evaluation of potential erg and epg changes to address ...15 task c1 – identify risk impact of...

Westinghouse Non-Proprietary Class 3

WCAP-16204 March 2004 Revision 1

Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SEE-0085) Volume 2 – Proposed Changes to Westinghouse Emergency Response Guidelines

WESTINGHOUSE NON-PROPRIETARY CLASS 3

Westinghouse Electric Company LLC P.O. Box 355

Pittsburgh, PA 15230-0355

© 2004 Westinghouse Electric Company LLC All Rights Reserved

6378Vol2_r1.doc-033104

WCAP-16204 Revision 1

Evaluation of Potential ERG and EPG Changes to Address

NRC Bulletin 2003-01 Recommendations (PA-SEE-0085)

Volume 2 – Proposed Changes to Westinghouse Emergency Response Guidelines

iii

WCAP-16204 March 2004 6378Vol2_r1.doc-033104 Revision 1

WESTINGHOUSE COPYRIGHT NOTICE AND LIABILITY STATEMENT

“This report bears a Westinghouse copyright notice. You as a member of the Westinghouse Owners Group are permitted to make the number of copies of the information contained in this report which are necessary for your internal use in connection with your implementation of the report results for your plant(s) in your normal conduct of business. Should implementation of this report involve a third party, you are permitted to make the number of copies of the information contained in this report which are necessary for the third party’s use in supporting your implementation at your plant(s) in your normal conduct of business, recognizing that the appropriate agreements must be in place to protect the proprietary information for the proprietary version of the report. All copies made by you must include the copyright notice in all instances and the proprietary notice if the original was identified as proprietary.”

“This report was prepared by Westinghouse as an account of work sponsored by the Westinghouse Owners Group (WOG). Neither the WOG, any member of the WOG, Westinghouse, nor any person acting on behalf of any of them:

• Makes any warranty or representation whatsoever, expressed or implied, (I) with respect to the use of any information, apparatus, method, process, or similar item disclosed in this report, including merchantability, and fitness for a particular purpose, (II) that such use does not infringe on or interfere with privately owned rights, including the party’s intellectual property, or (III) that this report is suitable to any particular user’s circumstance; or

• Assumes responsibility for any damages or other liability whatsoever (including any consequential damages, even if the WOG or any WOG representative has been advised of the possibility of such damages) resulting from any selection or use of this report or any information, apparatus, method, process, or similar item disclosed in this report.”

v


MASTER TABLE OF CONTENTS

VOLUME 1 – ENGINEERING EVALUATIONS AND ANALYSES REPORT

LIST OF FIGURES ..................................................................................................................................... xi

EXECUTIVE SUMMARY........................................................................................................................xiii

1 INTRODUCTION AND BACKGROUND..................................................................................1-1

2 EVALUATION ASSUMPTIONS .................................................................................................2-1 2.1 COMBUSTION ENGINEERING REFERENCE PLANT .............................................2-1

2.1.1 Safety Injection System (SIS)..........................................................................2-1 2.1.2 Containment Atmosphere Control System (CACS) ........................................2-5 2.1.3 Containment Isolation System (CIS) (07) .......................................................2-8

2.2 WESTINGHOUSE REFERENCE PLANT ..................................................................2-12 2.2.1 Safety Injection (SI) System..........................................................................2-12 2.2.2 Containment Spray System ...........................................................................2-18 2.2.3 Containment Atmosphere Control System ....................................................2-18 2.2.4 Containment Isolation System.......................................................................2-22

2.3 OPERATOR ACTION TIMES ......................................................................................2-25 2.3.1 Operator Actions With Time Assumptions ....................................................2-25 2.3.2 Standards Employed ......................................................................................2-26 2.3.3 Times Assumed..............................................................................................2-26

3 TASK B1/B13 – IDENTIFY UFSAR SECTIONS AFFECTED BY RECOMMENDED CHANGES....................................................................................................................................3-1 3.1 TASK OBJECTIVE.........................................................................................................3-1 3.2 IMPACT OF THROTTLING FLOW IN RECIRCULATION MODES ON

DESIGN BASIS ..............................................................................................................3-1 3.3 UFSAR SECTIONS TO BE CONSIDERED FOR REVIEW OR REVISION...............3-2 3.4 CONCLUSION................................................................................................................3-4

4 TASK B2 – IDENTIFICATION OF MANUAL OPERATOR ACTIONS ASSOCIATED WITH THE TERMINATION OF ECCS/CSS..............................................................................4-1 4.1 INTRODUCTION/TASK OBJECTIVE..........................................................................4-1 4.2 SUMMARY OF CHANGES TO MANUAL OPERATOR ACTIONS ...........................4-1 4.3 CONCLUSIONS ...........................................................................................................4-14

5 TASK B3 – REVIEW DESIGN BASIS ACCIDENT DOSE ANALYSIS ...................................5-1 5.1 INTRODUCTION/TASK OBJECTIVE..........................................................................5-1 5.2 SOURCE TERM METHODOLOGY..............................................................................5-1 5.3 EVALUATION APPROACH ..........................................................................................5-1 5.4 RESULTS SUMMARY ...................................................................................................5-2 5.5 IMPACT ON PLANT LICENSING BASIS....................................................................5-2

vi


MASTER TABLE OF CONTENTS (cont.)

5.6 CONCLUSIONS .............................................................................................................5-2 5.7 REFERENCES ................................................................................................................5-2

6 TASK B4 – IMPACT ON THE LOCA M&E ANALYSIS FOR LARGE DRY CONTAINMENTS .......................................................................................................................6-1 6.1 INTRODUCTION & TASK OBJECTIVE......................................................................6-1 6.2 LOCA MASS AND ENERGY RELEASE ANALYSES.................................................6-1 6.3 CONTAINMENT ANALYSIS RESULTS.......................................................................6-2 6.4 CONCLUSIONS .............................................................................................................6-2

7 TASK B5 – IMPACT ON THE LOCA M&E ANALYSIS FOR ICE CONDENSER CONTAINMENT .........................................................................................................................7-1 7.1 INTRODUCTION/TASK OBJECTIVE..........................................................................7-1 7.2 IMPACT TO CONTAINMENT PRESSURE M&E ANALYSIS FOR ICE

CONDENSER CONTAINMENT....................................................................................7-1 7.3 STRATEGIES FOR DELAYING CONTAINMENT SPRAY ACTUATION .................7-1 7.4 IMPACT ON PLANT LICENSING CRITERIA.............................................................7-1 7.5 CONCLUSIONS .............................................................................................................7-2

8 TASK B6 – IMPACT ON CONTAINMENT SUMP CHEMISTRY............................................8-1 8.1 OBJECTIVE ....................................................................................................................8-1 8.2 IMPACT ON SUMP PH AND IODINE REMOVAL......................................................8-1

8.2.1 Addition of Water Without Boron ...................................................................8-1 8.2.2 Addition of Water With Boron.........................................................................8-2

8.3 CONSIDERATION OF SAFETY INJECTION FLOW REQUIREMENTS ..................8-2 8.4 CONCLUSIONS .............................................................................................................8-2 8.5 REFERENCES ................................................................................................................8-3

9 TASK B7 – DETERMINE THE OPTIMAL RATE OF ADDITION (CE PLANT ONLY).........9-1 9.1 INTRODUCTION/TASK OBJECTIVE..........................................................................9-1 9.2 DISCUSSION..................................................................................................................9-1 9.3 CONCLUSION................................................................................................................9-1

10 TASK B8 – SECURING ONE TRAIN OF HPSI BEFORE AND AFTER TRANSFER TO RECIRCULATION ..............................................................................................................10-1 10.1 INTRODUCTION .........................................................................................................10-1 10.2 CRITERIA FOR SECURING ONE TRAIN .................................................................10-2 10.3 RESTART CRITERIA...................................................................................................10-4 10.4 IMPACT ON CORE COOLING OF A SINGLE FAILURE AFTER SECURING

ONE TRAIN ..................................................................................................................10-4 10.5 IMPACT ON EPG SER COMMITMENTS AND NUREG 0737

REQUIREMENTS.........................................................................................................10-5 10.6 CONCLUSIONS ...........................................................................................................10-5

vii



11 TASK B9 – SECURING ONE TRAIN OF LPSI BEFORE AND AFTER RECIRCULATION ACTUATION (CE NSSS ONLY) .............................................................. 11-1 11.1 INTRODUCTION ......................................................................................................... 11-1 11.2 PROCEDURE CHANGES............................................................................................ 11-1 11.3 IMPACT ON CORE COOLING OF A SINGLE FAILURE AFTER

SECURING ONE TRAIN ............................................................................................. 11-1 11.4 IMPACT ON EPG SER COMMITMENTS AND NUREG 0737

REQUIREMENTS......................................................................................................... 11-2 11.5 CONCLUSIONS ........................................................................................................... 11-2

12 TASK B10 – SECURING CSS PRIOR TO AND AFTER RECIRCULATION ALIGNMENT.............................................................................................................................12-1 12.1 INTRODUCTION/ TASK OBJECTIVE.......................................................................12-1 12.2 CRITERIA FOR REDUCING/SECURING SPRAY AND THE IMPACT OF

MISDIAGNOSIS...........................................................................................................12-1 12.3 APPROPRIATE RESTART CRITERIA........................................................................12-2 12.4 IMPACT ON CONTAINMENT PRESSURE/TEMPERATURE RESULTS................12-2 12.5 IMPACT ON OFF-SITE DOSE OF A SINGLE FAILURE AFTER

SECURING SPRAY......................................................................................................12-2 12.6 IMPACT ON PLANT LICENSING BASES.................................................................12-2 12.7 IMPACT ON EPG SER COMMITMENTS AND NUREG 0737

REQUIREMENTS.........................................................................................................12-2 12.8 CONCLUSIONS ...........................................................................................................12-2

13 TASK B11 – EVALUATE THE IMPACT ON OPERATOR RESPONSE TIMES ....................13-1 13.1 INTRODUCTION/TASK OBJECTIVE........................................................................13-1 13.2 OPERATOR RESPONSE TIME OF SECURING ONE TRAIN (HPSI, LPSI,

OR CS) EARLY.............................................................................................................13-1 13.3 IMPACT ON OPERATOR RESPONSE TIME EVALUATIONS.................................13-2 13.4 CONCLUSIONS ...........................................................................................................13-3

14 TASK B12 – REVIEW THE NUREG-1431 AND 1432, STANDARD TECHNICAL SPECIFICATIONS FOR WESTINGHOUSE AND COMBUSTION ENGINEERING PLANTS BASES........................................................................................................................14-1 14.1 INTRODUCTION/TASK OBJECTIVE........................................................................14-1 14.2 SECURE ONE OR TWO CONTAINMENT SPRAY PUMP(S) BEFORE

RECIRCULATION ALIGNMENT ...............................................................................14-1 14.2.1 TS 3.6.6 (A and B) Containment Spray and Cooling Systems......................14-1 14.2.2 TS 3.6.7 Spray Additive System (Atmospheric and Dual) ............................14-2

14.3 MANUALLY ESTABLISH ONE TRAIN OF CONTAINMENT SUMP RECIRCULATION PRIOR TO AUTOMATIC ACTUATION .....................................14-2 14.3.1 TS3.3.4 ESFAS Instrumentation Recirculation Actuation Signal .................14-2

viii



14.4 TERMINATE ONE TRAIN OF HPSI/HIGH-HEAD INJECTION AFTER RECIRCULATION ALIGNMENT ...............................................................................14-3

14.5 TERMINATE LPSI/RHR PUMP PRIOR TO RECIRCULATION ALIGNMENT.......14-3 14.6 REFILL REFUELING WATER STORAGE TANK......................................................14-3 14.7 INJECT MORE THAN ONE RWT/RWST VOLUME FROM REFILLED

RWT/RWST OR BY BYPASSING RWT/RWST..........................................................14-3 14.7.1 TS 3.3.11 PAM Instrumentation ....................................................................14-3

14.8 PROVIDE MORE AGGRESSIVE COOLDOWN AND DEPRESSURIZATION FOLLOWING A SMALL BREAK LOCA....................................................................14-4 14.8.1 TS 3.4.3 RCS Pressure and Temperature (P/T) Limits..................................14-4

14.9 PROVIDE GUIDANCE ON SYMPTOMS AND IDENTIFICATION OF CONTAINMENT SUMP BLOCKAGE ........................................................................14-5

14.10 DEVELOP CONTINGENCY ACTIONS IN RESPONSE TO: CONTAINMENT SUMP BLOCKAGE, LOSS OF SUCTION, AND CAVITATION ...............................14-5

14.11 TERMINATE ONE TRAIN OF HPSI/HIGH-HEAD INJECTION PRIOR TO RECIRCULATION ALIGNMENT ...............................................................................14-5

14.12 DELAY CONTAINMENT SPRAY ACTUATION FOR SMALL BREAK LOCA IN ICE CONDENSER PLANTS...................................................................................14-5

14.13 CONCLUSION..............................................................................................................14-5

15 TASK C1 – IDENTIFY RISK IMPACT OF ERG/EPG CHANGES (PRA EVALUATION) ....15-1 15.1 PROVIDE GUIDANCE ON SYMPTOMS AND IDENTIFICATION OF

CONTAINMENT SUMP BLOCKAGE AND DEVELOP CONTINGENCY ACTIONS (COA 8 AND 9)...........................................................................................15-1

15.2 PROVIDE GUIDANCE ON SYMPTOMS AND IDENTIFICATION OF CONTAINMENT SUMP BLOCKAGE AND DEVELOP CONTINGENCY ACTIONS AND TERMINATE ONE TRAIN OF INJECTION AFTER RECIRCULATION ALIGNMENT (COA 3, 8 AND 9) ................................................15-2

15.3 TERMINATE ONE TRAIN OF INJECTION AFTER RECIRCULATION ALIGNMENT, REFILL THE REFUELING WATER STORAGE TANK, AND INJECT MORE THAN ONE VOLUME RWST VOLUME (COA 3, 5, AND 6) ........15-2

15.4 TERMINATE ONE TRAIN OF INJECTION PRIOR TO RECIRCULATION ALIGNMENT, REFILL THE REFUELING WATER STORAGE TANK, AND INJECT MORE THAN ONE VOLUME RWST VOLUME (COA 10, 5, AND 6).......15-3

15.5 MANUAL TRANSFER OF ONE ECCS TO THE CONTAINMENT SUMP PRIOR TO AUTOMATIC RECIRCULATION ALIGNMENT, REFILL THE REFUELING WATER STORAGE TANK, AND INJECT MORE THAN ONE VOLUME RWST VOLUME (COA 2, 5, AND 6) ........................................................15-4

15.6 SECURE ONE CONTAINMENT SPRAY PUMP BEFORE RECIRCULATION ALIGNMENT, PROVIDE GUIDANCE ON SYMPTOMS AND IDENTIFICATION OF CONTAINMENT SUMP BLOCKAGE, TERMINATE LPSI/RHR PUMP PRIOR TO RECIRCULATION ALIGNMENT, REFILL THE REFUELING WATER STORAGE TANK, AND INJECT MORE THAN ONE VOLUME RWST VOLUME (COA 1, 4, 8, 5, AND 6) ................................................15-5

ix



16 TASK D3 – IMPACT ON EOP SETPOINTS.............................................................................16-1 16.1 INTRODUCTION/TASK OBJECTIVE........................................................................16-1 16.2 IDENTIFY IMPACTS TO EOP SETPOINTS AS A RESULT OF ERG CHANGES...16-1 16.3 GENERIC EVALUATION OF IMPACT ON SETPOINT UNCERTAINTIES ............16-1 16.4 CONCLUSIONS ...........................................................................................................16-2

17 TASK E3 – DEVELOP THE TECHNICAL BASES FOR ANY NEW EPG ACTION VALUES THAT MAY BE REQUIRED .....................................................................................17-1

18 TASK E4 – CONDUCT TABLE-TOP REVIEW .......................................................................18-1

19 TASK E5 – CONDUCT VALIDATION ON FULL SCOPE SIMULATOR ..............................19-1

APPENDIX A CANDIDATE OPERATOR ACTION (COA) EVALUATIONS....................................A-1 A1a-CE – Candidate Operator Action 1A – Combustion Engineering Plants Operator Action to Secure One Spray Pump ..................................................................A-1 A1a-W – Candidate Operator Action 1A – Westinghouse Plants Operator Action to Secure One Spray Pump .............................................................................................A-8 A1a-Ice Addendum – Candidate Operator Action 1A – Westinghouse Ice Condenser Plants Operator Action to Secure One Spray Pump....................................A-15 A1b – Candidate Operator Action 1B Operator Action to Secure Both Spray Pumps .................................................................................................................A-21 A2 – Candidate Operator Action 2 Manually Establish One Train of Containment Sump Recirculation Prior to Automatic Actuation .......................................................A-28 A3-CE – Candidate Operator Action 3 – Combustion Engineering Plants Terminate One Train of HPSI/High-Head Injection After Recirculation Alignment....A-32 A3-W – Candidate Operator Action 3 – Westinghouse Plants Terminate One Train of Safety Injection After Recirculation Alignment .......................................................A-40 A4 – Candidate Operator Action 4 Early Termination of One LPSI/RHR Pump Prior to Recirculation Alignment ..................................................................................A-47 A5 – Candidate Operator Action 5 Refill of Refueling Water Storage Tank ................A-52 A6 – Candidate Operator Action 6 Inject More Than One RWST Volume From a Refilled RWST or by Bypassing the RWST .................................................................A-60 A7 – Candidate Operator Action 7 Provide More Aggressive Cooldown and Depressurization Following A Small Break LOCA......................................................A-73 A8-CE – Candidate Operator Action 8 – Combustion Engineering Plants Provide Guidance on Symptoms and Identification of Containment Sump Blockage...............A-76 A8-W – Candidate Operator Action 8 – Westinghouse Plants Provide Guidance on Symptoms and Identification of Containment Sump Blockage...............................A-82 A9-CE – Candidate Operator Action 9 – Combustion Engineering Plants Develop Contingency Actions in Response to: Containment Sump Blockage, Loss of Suction, and Cavitation....................................................................................A-86

x



A9-W – Candidate Operator Action 9 – Westinghouse Plants Develop Contingency Actions in Response to: Containment Sump Blockage, Loss of Suction, and Cavitation.................................................................................................A-92 A10 – Candidate Operator Action 10 Early Termination of One Train of HPSI/High-Head Injection Prior to Recirculation Alignment (RAS) .........................A-104 A11 – Candidate Operator Action 11 Prevent or Delay Containment Spray for Small Break LOCAs (<1.0 Inch Diameter) in Ice Condenser Plants.......................... A-110

APPENDIX B LOCA ANALYSES IN SUPPORT OF RESOLUTION OF THE SUMP BLOCKAGE ISSUE....................................................................................................... B-1

B.1 INTRODUCTION ............................................................................................. B-1 B.2 RELAP5 DATABASE ....................................................................................... B-1 B.3 ACCIDENT SCENARIOS ANALYZED .......................................................... B-1 B.4 LOCA ANALYSIS RESULTS........................................................................... B-2 B.5 CONCLUSIONS ............................................................................................... B-4

VOLUME 2 – PROPOSED CHANGES TO WESTINGHOUSE EMERGENCY RESPONSE GUIDELINES

1 INTRODUCTION ........................................................................................................................1-1

VOLUME 3 – PROPOSED CHANGES TO CEN-152 (COMBUSTION ENGINEERING EMERGENCY PROCEDURE GUIDELINES)

1 INTRODUCTION ........................................................................................................................1-1

2 TASK E5 – FULL SCOPE SIMULATOR VALIDATION OF POTENTIAL EPG CHANGES TO ADDRESS NRC BULLETIN 2003-1 RECOMMENDATIONS .......................2-1 2.1 INTRODUCTION/TASK OBJECTIVE..........................................................................2-1 2.2 VALIDATION SCENARIOS ..........................................................................................2-1 2.3 VALIDATION GUIDELINES.........................................................................................2-2 2.4 RESULTS ........................................................................................................................2-2 2.5 CONCLUSIONS .............................................................................................................2-6

3 EMERGENCY PROCEDURE GUIDELINES ............................................................................3-1

1-1


1 INTRODUCTION

Volume 2 of this report contains the following documents:

• WOG Generic Guideline SBCRG, Sump Blockage Control Room Guideline Revision 0 Validation Report

• Westinghouse Emergency Response Guidelines and Bases document

– Direct Work Item DW-03-018

– Direct Work Item DW-03-020

– Sump Blockage Control Room Guideline

– Background Information for Westinghouse Owners Group Sump Blockage Guideline

WOG Generic Guideline SBCRG, Sump Blockage Control Room Guideline

Revision 0 Validation Report

WOG GENERIC GUIDELINE SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE

REVISION 0 VALIDATION REPORT

AUTHORS

S. R. Prokopovich D. M. Roehlich D. M. Scheef

March 2004

i

SUMMARY

The Sump Blockage Control Room Guideline (SBCRG) was developed by the

Westinghouse Owners Group (WOG) to provide generic guidance for responding to

a recirculation sump blockage condition that prevents establishing or maintaining at

least one train of ECCS flow in the recirculation mode. To demonstrate the

effectiveness of SBCRG, the guideline was subjected to a thorough validation test

in January 2004 at the Shearon Harris Nuclear Plant simulator. This test concluded

that for various degrees of containment sump blockage, SBCRG was effective in

providing operator direction for balancing the need for safety injection flow for core

cooling while trying protecting the safety injection pumps from loss of suction due to

sump blockage.

This validation successfully demonstrated that the new SBCRG generic guideline

was usable and operationally correct. The changes resulting from the validation

exercises were incorporated into SBCRG prior to its formal transmittal to WOG

members.

ii

ACKNOWLEDGMENTS

The success of this project was dependent upon the contributions of many

individuals. Their personal commitment and professional attitude is gratefully

acknowledged:

The Westinghouse Owners Group Procedures Working Group, and chairman

Dennis Baker, who provided valuable guidance.

The SBCRG Core Review Group, who devoted considerable time and effort to

perform an extensive review of the SBCRG guideline to verify its written correctness

and technical accuracy. Special thanks to: Jim Abshire, Dennis Baker, Jim Brau,

Dave Kelly, Pete Sidelinger, Doug Smith, Hank Stroup and Mike Weiner.

Hank Stroup, who organized the Shearon Harris Nuclear Plant personnel and

simulator activities and also coordinated the validation activities between the WOG

and Progress Energy.

The Shearon Harris Nuclear Plant simulator operator and operating crews who

performed admirably under a very demanding schedule considering there was very

little preparation time and no special training. Special thanks to Mac McDade for

his excellent support at running the simulator and adjusting the malfunctions to

achieve the desired simulated sump blockage. Also special thanks to the plant

operators: Tim English, Ed Lipetzky, Robert Smith, David Corlett, Randy Wilson,

and Jeff Trogdon.

The WOG validation team, consisting of members of the Procedures Working

Group and Westinghouse who provided valuable input and comments during the

validation test. Thanks to: Dennis Baker, Bob Bleacher, Charles Eberle, David

McIntosh, Vic Smith, Hank Stroup, Terry Vandenbosch, Mike Weiner, Rich

Prokopovich, Paul Marcucci, Don Roehlich and Donald Scheef.

iii

SBCRG VALIDATION REPORT

TABLE OF CONTENTS

Topic Page No.

1.0 INTRODUCTION 1

2.0 OBJECTIVES 4

3.0 SBCRG DOCUMENTATION REVIEW 4

4.0 VALIDATION PROGRAM 5

4.1 Preparation Phase 5

4.1.1 Scope of Validation 5

4.1.2 Validation Method 5

4.1.3 Validation Criteria 6

4.1.3.1 Usability 7

4.1.3.1.1 Level of Detail 7

4.1.3.1.2 Understandability 7

4.1.3.2 Operational Correctness 8

4.1.3.2.1 Reference Plant Compatibility 8

4.1.3.2.2 Operator Compatibility 8

4.1.4 Validation Test ARG 8

4.1.5 Test Scenarios 9

4.1.6 Observation Team 11

4.1.7 Operating Crew 12

4.2 Assessment Phase 12

4.3 Resolution Phase 14

4.4 Documentation Phase 14

5.0 RESULTS AND CONCLUSIONS 14

5.1 Usability 15

5.1.1 Level of Detail 15

5.1.2 Understandability 15

5.1.3 Conclusion on Usability 16

iv

TABLE OF CONTENTS (cont.)

Topic Page No.

5.2 Operational Correctness 17

5.2.1 Reference Plant Compatibility 17

5.2.2 Operator Compatibility 17

5.2.3 Conclusion on Operational Correctness 18

5.3 General Conclusion from the SBCRG 18

Validation Test

6.0 RECOMMENDATIONS 19

6.1 Guideline Change 19

6.2 Information To Include In The Background Document 19

6.3 No Change Required 20

6.4 Addressed By Another Discrepancy Sheet 20

6.5 Conclusion on Recommendations 20

7.0 APPLICATION TO PLANT SPECIFIC VALIDATION 21

8.0 REFERENCES 22

List of Tables

4.1 SBCRG Validation Test Scenarios 10

APPENDICES

APPENDIX A DEFINITIONS AND ABBREVIATIONS

APPENDIX B SBCRG (GENERIC GUIDELINE AS OF DATE OF

VALIDATION)

APPENDIX C SHEARON HARRIS VALIDATION COPY OF SBCRG

APPENDIX D SBCRG VALIDATION DISCREPANCY FORMS

APPENDIX E SBCRG VERIFICATION AND VALIDATION

DOCUMENTATION FORMS

1

1.0 INTRODUCTION

On June 9, 2003, the NRC issued NRC Bulletin 2003-01, “Potential Impact of

Debris Blockage on Emergency Sump Recirculation at Pressurized-Water

Reactors.” It was issued to inform licensees of the potential for additional

adverse effects due to debris blockage of flow paths necessary for

Emergency Core Cooling System (ECCS) and Containment Spray System

(CSS) recirculation and containment drainage. These additional adverse

effects were based on NRC-sponsored research that identified the potential

susceptibility of Pressurized Water Reactor (PWR) recirculation sump

screens to debris blockage in the event of a High Energy Line Break (HELB)

that would require ECCS and CSS operation in the recirculation mode.

NRC Bulletin 2003-01 required licensees to provide a written response within

60 days in accordance with 10 CFR 50.54(f) to either:

1. State that the ECCS and CSS recirculation functions have been

analyzed with respect to the potentially adverse post-accident debris

blockage effects identified in the NRC Bulletin are in compliance with

10 CFR 50.46(b)(5) and all existing applicable regulatory requirements

(Option 1), or

2. Describe any interim compensatory measures that have been or will

be implemented to reduce the risk which may be associated with the

potentially degraded or nonconforming ECCS and CSS recirculation

functions until an evaluation to determine compliance has been

completed (Option 2).

One of the Bulletin 2003-01 recommendations was to develop contingency

actions in response to containment sump blockage, loss of suction, and

cavitation. The WOG Procedures Working Group was tasked by the WOG

to develop the applicable guidance. Guideline SBCRG, SUMP BLOCKAGE

2

CONTROL ROOM GUIDELINE, provides the interim compensatory guidance

for responding to sump blockage during recirculation-mode operation of the

Emergency Core Cooling System (ECCS) and/or Containment Spray (CS)

System. SBCRG was written to be applicable to those situations in which

sump blockage causes the guidance in the Emergency Response Guidelines

(ERGs) to be ineffective. Operators enter this guideline based upon

indications of loss of pump suction caused by recirculation sump blockage

that prevents establishing or maintaining at least one train of ECCS flow in

the recirculation mode.

The SBCRG guidance is a part of the interim measures in response to NRC

Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump

Recirculation at Pressurized-Water Reactors. The guidance is interim in

nature because future actions (analysis and/or plant modifications) must

resolve the associated Generic Safety Issue (GSI) 191. Individual facilities

that have achieved long-term resolution of GSI 191 no longer require interim

compensatory actions.

This generic guidance for responding to sump blockage is in the form of a

“Control Room Guideline” separate from the Emergency Response Guideline

network. Issuance of the SBCRG does not change the ERG network nor

does it create a requirement for any plant to incorporate the content of this

guideline into the approved plant procedures. The format and style of the

SBCRG is consistent with the ERG Writer’s Guide. The SBCRG borrows

elements and information from the ERGs, including the Footnotes (and, by

inference, the Footnote Basis Document), the Plant Engineering Staff

Evaluation document (part of the Executive Volume, Generic Issues section)

and various ERGs and associated Background Documents. Usage of the

ERG Format and writing rules simplifies the burden of the utility procedure

writers in implementing plant-specific procedures based on this guideline.

The procedure writers would then be able to use the same process that they

used for the generation of their plant emergency operating procedures. This

3

provides individual plants the greatest flexibility in implementing the

guidance. Individual plants may select the implementation strategy best

suited to their needs. Appropriate ERG definitions and abbreviations can be

found in Appendix A.

Consistent with the Configuration and Control procedure and the procedure

for validating ERG revisions, a simulator validation of SBCRG was conducted

at Shearon Harris Power Station, Unit 2 simulator on January 29, 2004.

Following the validation exercise, the discussion and disposition the findings

occurred at a meeting held later in that week.

4

2.0 OBJECTIVES

The validation of SBCRG was performed in the same manner that was used

to validate the ERGs. Validation of the ERGs/ARGs is a structured process

which demonstrates that actions specified in the ERGs/ARGs can be

followed by trained operators to manage emergency conditions. Validation is

a performance evaluation that addresses whether or not the ERGs/ARGs are

usable and operationally correct. Usability ensures that the ERGs/ARGs

provide sufficient and understandable information. Operational correctness

ensures that the ERGs/ARGs are compatible with the reference plant and

the operator.

Therefore, the objectives of the SBCRG Validation were to demonstrate that

the actions in SBCRG are usable and operationally correct.

3.0 SBCRG DOCUMENTATION REVIEW

Prior to validation, the pre-validation draft version of SBCRG was subjected

to an extensive review by the WOG SBCRG Core Review Group to ensure

its written correctness and technical accuracy. The pre-validation draft

version of SBCRG is provided in Appendix B.

To facilitate testing of SBCRG, the Shearon Harris footnote and setpoint

values and Shearon Harris specific nomenclature were incorporated into the

pre-validation draft version of SBCRG to produce a validation version of

SBCRG. This modification was made with minimal perturbation to the

wording and usage of the SBCRG. The Shearon Harris Validation Version of

SBCRG is provided in Appendix C.

5

4.0 VALIDATION PROGRAM

This section describes the actual validation test for SBCRG. The simulator

format was derived from the guidance provided in Reference 13. The

validation consisted of four phases: preparation, assessment, resolution and

documentation.

4.1 Preparation Phase

During this phase, the resources required for the program were identified, the

validation method to be used was selected, the test scenarios were selected

and developed, and the extent and application of validation criteria were

determined.

4.1.1 Scope of Validation

The test program evaluated the effectiveness of the SBCRG in responding to

a selected set of simulated sump blockage scenarios. A validation version of

SBCRG was modified to include Shearon Harris plant-specific details and

setpoints. This Shearon Harris specific validation version of SBCRG was

then provided to the Operating Crews.

4.1.2 Validation Method

The actual validation was done on the Shearon Harris simulator. Two normal

operating crews used a Shearon Harris specific validation version of SBCRG

to guide their actions in response to control room (plant/simulator) indications

during the simulated sump blockage scenarios. Detailed observations were

made of operator performance, procedure usage, and plant response by the

observation team.

6

4.1.3 Validation Criteria

In order to accurately assess the effectiveness of SBCRG during simulated

sump blockage scenarios, specific criteria have been developed. The typical

ERG/ARG evaluation criteria is broken down into the following two major

areas:

• usability

- level of detail

- understandability

• operational correctness

- reference plant compatibility

- operator compatibility

The success of the validation is contingent upon input from the entire

validation team. Without comprehensive input, the results of the validation

may not be all inclusive. This section contains the evaluation criteria used in

determining the usability and operational correctness of the guideline. The

Observation Team members used this evaluation criteria as a detailed guide

for recording any possible guideline problems. The Operating Crew was also

briefed on the evaluation criteria in order to provide more comprehensive

input during the simulator exercises and the debriefing sessions.

7

4.1.3.1 Usability

4.1.3.1.1 Level of Detail

• Is sufficient information provided in order to perform the

specified actions for each step?

• Are the actions explicit or adequately described at each

decision point (use of “OR”)?

• Are the contingency actions sufficient to address the observed

symptoms?

4.1.3.1.2 Understandability

• Are the SBCRG steps easy to read and readily

understandable?

• Are the figures and tables easy to read with sufficient accuracy?

• Are caution and note statements readily understandable and

complied with?

8

4.1.3.2 Operational Correctness

4.1.3.2.1 Reference Plant Compatibility

• Can the actions specified in the guideline be performed in the

designated sequence?

• Are adequate plant symptoms provided in the SBCRG that

enable the operator to perform the actions specified?

4.1.3.2.2 Operator Compatibility

• Can the guideline action steps be performed by the operating

crew?

• Can the operating crew follow the designated action step

sequences?

• Can particular steps or sets of steps be readily located when

required?

• Are SBCRG entry and exit points specified adequately?

4.1.4 Validation Test SBCRG

The generic SBCRG validated was the pre-validation draft version of SBCRG

that was subjected to an extensive review by the WOG SBCRG Core Review

Group to ensure its written correctness and technical accuracy. Every effort

was made to keep the Shearon Harris specific validation version of SBCRG

as similar to the generic guideline as possible to facilitate transfer of

validation results. The generic SBCRG validated and the corresponding

Shearon Harris specific validation version of SBCRG are presented in

9

Appendices B and C, respectively. The transition from the ERGs to SBCRG

was accomplished by placing a small sheet of self-stick removable note

paper in the Shearon Harris ES-1.3 procedure telling the operators to go to

SBCRG if both RHR pumps are cavitating after the recirculation alignment.

4.1.5 Test Scenarios

The SBCRG Validation program consisted of 8 scenarios. The 8 scenarios

are listed in Table 4.1.

10

TABLE 4.1

SBCRG VALIDATION TEST SCENARIOS

1. Large LOCA. At time of recirculation, ramp sump blockage to full blockage in

ten minutes on both trains. Blockage cannot be corrected. 2. IC small break LOCA (7% of 4.5 inch) at time of recirculation. At time of

recirculation, ramp sump blockage to full blockage in ten minutes or so on both trains. Blockage cannot be corrected.

3. IC large LOCA at time of recirculation. At time of recirculation, sump blockage

allows only flow of about one CSIP or so on each train. Blockage cannot be corrected. Blockage used was 96% (140 lb/sec).


allows only flow of about on half of one CSIP or so in one train. Other train completely blocked. Blockage cannot be corrected. Blockage used was 98% (70 lb/sec).


allows only flow of about one CSIP or so in one train. Other train completely blocked. Blockage cannot be corrected. Train A blockage is full, Train B blockage at 96% (140 lb/sec).


allows only flow of about on half of one CSIP or so in one train and one CSIP in the other train. Blockage cannot be corrected. Train A blockage is at 98% (70 lb/sec), Train B blockage at 96% (140 lb/sec).


allows only flow of about more than one CSIP or so in one train and full blockage in the other train. Blockage cannot be corrected. Train A blockage at 90%. Train B blockage is full.


allows only flow of about more than one CSIP or so in one train and full blockage in the other train. Blockage cannot be corrected. Three fan coolers are failed. Train A blockage at 90%. Train B blockage is full.

11

4.1.6 Observation Team

Each of the test scenarios was observed by an Observation Team. The

team was responsible for identifying deviations from nominal (expected)

performance observed during the scenario. The team was made up of:

• Westinghouse personnel familiar with ERG/ARG development,

human factors evaluations and power plant operations.

• Several members from the WOG Procedures Working Group

familiar with ERG/ARG development and with expertise in

operations, training and/or procedures.

Each individual on the observation team was briefed in his duties as an

observer. Checklists stating the Validation Evaluation Criteria were provided

as constant reminders of the expected nominal performance.

It was the observation team’s responsibility to record all observed deviations,

real or suspected, positive or negative, discuss them subsequently with the

operators during the debriefing session, make an initial evaluation of the

cause, and, with the operators input, suggest possible resolutions.

12

4.1.7 Operating Crew

Two full crews of operators were provided by Shearon Harris. Each crew

consisted of at least a Shift Supervisor, two Reactor Operators, and a Shift

Technical Advisor (STA).

4.2 Assessment Phase

This phase comprised the actual simulator exercises of the test scenarios

including SBCRG usage by the operators. The simulator exercises were

conducted during one 8 hour shift.

Orientation for test participants was completed at the beginning of the

simulator test day and all necessary materials were on hand. Selection of

the test scenarios to be run was made randomly on the day of the test.

For each test scenario, the following sequence was observed.

1. The simulator instructor initialized the simulation and properly aligned

the control board.

2. One full operating crew entered the control room and was briefed on

current plant operating and equipment status, and given operating

instructions (i.e., raise or lower power, synchronize generator, reactor

startup, etc.).

3. The observation crew took up positions in the back of the control

room, which provided them an unobstructed view of the entire control

room. They had several copies of the validation version of SBCRG.

4. When directed by the observation team leader, the simulator instructor

activated the simulation and the computer data recording program.

13

5. After a minute or two of “steady-state” operation, the malfunctions

specified for the test scenario were input at the instructor’s console.

6. The operators responded to indicated plant conditions using SBCRG.

Observations and plant data were recorded.

7. At some appropriate time, determined by the observation team leader,

the test scenario was terminated. Most often, termination

corresponded to the achievement of some steady-state condition or

controlled, longer-term process.

8. Operators and observation team members proceeded to a debriefing

room, taking along all observation notes.

9. In the debriefing session, all noted observations were discussed.

Comments were recorded on forms provided for this purpose. Copies

of SBCRG were available in the debriefing room. At the same time,

the second operating crew and observation team began the next

scenario in the control room.

10. All discrepancy forms for each scenario were cataloged by a scenario

and discrepancy number for future reference and analysis.

11. Following the debriefing, the operating crew and observation team

were free until called for their next test scenario.

14

4.3 Resolution Phase

At the end of the validation test, all valid discrepancies were reviewed and

proposed resolutions were presented to the WOG Procedures Working

Group for approval. All discrepancies and/or resolutions were documented

on Discrepancy Forms (see Appendix D). Electronic signatures were

provided by the lead evaluators.

4.4 Documentation Phase

An ERG Verification and Validation Documentation Form for each scenario

was completed to signify that all open items were satisfactorily resolved and

that all required actions as outlined in the validation program were properly

executed. The forms were then reviewed by the Procedures Working Group

Chairman and the Westinghouse Plant Operations Manager and electronic

signatures were attached. Appendix E contains the forms with the electronic

signatures.

5.0 RESULTS AND CONCLUSIONS

Conclusions based on the actual test observations and the resulting

documentation are as follows:

1) A significant number of comments on SBCRG were discussed relating

particularly to wording and usage of the SBCRG.

2) Of the 62 documented discrepancies, 17 discrepancies were

recommended to be incorporated into SBCRG prior to the issuance,

3 discrepancies were recommended to be incorporated into the

15

SBCRG Background Document, 28 had no impact on the guidelines,

and 14 discrepancies were addressed by previous items. Section 6

contains a more detailed discussion of the discrepancies.

5.1 Usability

The principle of usability is one of the major aspects of validation

demonstrated by the test results. It is broken down into two procedure

characteristics: level of detail and understandability, which together indicate

that SBCRG provides sufficient and understandable information to the

operator.

5.1.1 Level of Detail

This characteristic means that the guideline contains sufficient information for

the operator to properly perform the required actions. The test results

showed that the operators were able to perform the expected actions and

make the required diagnoses using the information provided in the SBCRG.

5.1.2 Understandability

This characteristic means that the user can understand the information

presented in the guideline. Very few cases of operator confusion were

noted. The particular wording or step construction responsible for most of

the test observations can be easily corrected in the plant-specific procedure

or by special training emphasis. In nearly all scenarios, the information

presented in the SBCRG was plainly understood, as evidenced by correct

implementation. The meanings of NOTEs and CAUTIONs were plainly

understood.

Based on the test observations, the criteria of understandability was satisfied

by the test SBCRG.

16

5.1.3 Conclusion on Usability

The multiple aspects of usability were adequately demonstrated by the

validation test of SBCRG.

17

5.2 Operational Correctness

The principle of operational correctness indicates the degree to which

SBCRG is adequate to provide proper operational guidance in the

development of a plant-specific procedure based on simulated plant

responses to manage a sump blockage event. For the case of SBCRG, the

characteristics evaluated were the reference plant compatibility and the

operator compatibility.

5.2.1 Reference Plant Compatibility

This characteristic means that the guideline is compatible with the reference

plant. The test results showed that the actions specified in the guidelines

can be performed in the designated sequence and that the plant symptoms

enabled the operator to use SBCRG.

5.2.2 Operator Compatibility

This characteristic means that the guideline is compatible with shift manning

levels and policies. While control room staffing is not explicitly defined in the

ERG/ARG programs, it is recognized that all plants require a minimum shift

compliment composed of at least one Senior Reactor Operator (SRO) and

two Reactor Operators (ROs) or equivalent. The test results showed that the

SBCRG Operating Crew was able to perform the guideline actions and follow

the designated action step sequences. In addition, the Operating Crew had

no problems in locating particular steps or sets of steps.

18

5.2.3 Conclusion on Operational Correctness

The principle of operational correctness was adequately demonstrated by the

validation test. It can be concluded that SBCRG demonstrated compatibility

with the reference plant and that the intent of SBCRG could be effectively

implemented by the Operating Crews.

5.3 General Conclusion from the SBCRG Validation Test

From the information presented above, it can be concluded that SBCRG is

technically correct and provides a set of generic guidance which supports

efficient and correct management of sump blockage events.

19

6.0 RECOMMENDATIONS

As a result of the simulator testing and the debriefing sessions,

62 Discrepancy Sheets were submitted to the Core Team for resolution. The

Discrepancy Sheets were labeled by their scenario number (e.g., 1-1, 2-1,

etc.). The Core Team evaluated each of the discrepancies on the day

following the validation exercise and concurred on resolutions for each of

them. The approved resolutions to the 62 Discrepancy Sheets fall into four

categories: 1) guideline change (including associated background change if

appropriate), 2) information to include in the background document, 3) no

change required and 4) addressed by another Discrepancy Sheet.

6.1 Guideline Change

The 17 discrepancies were placed in this category that resulted in a change

to the guideline.

1-3

1-11

2-7

8-4

1-5

1-20

2-8

8-5

1-8

1-22

3-3

1-9

1-23

3-5

1-10

2-6

4-3

6.2 Information To Include In The Background Document

The 3 discrepancies were placed in this category that resulted in additional

information being added to the background document.

1-2

1-7

5-1

20

6.3 No Change Required

The 28 discrepancies were placed in this category that resulted in no

change.

1-1

1-14

1-19

2-9

5-4

7-1

1-4

1-15

1-21

3-1

6-1

8-1

1-6

1-16

2-1

4-4

6-2

8-2

1-12

1-17

2-2

4-6

6-3

1-13

1-18

2-4

5-2

6-4

6.4 Addressed By Another Discrepancy Sheet

The 14 discrepancies were placed in this category since they were

addressed by the resolution of other Discrepancy Sheets.

2-3

4-2

6-5

2-5

4-5

6-6

3-2

4-7

7-2

3-4

5-3

8-3

4-1

5-5

6.5 Conclusion on Recommendations

All of the above recommendations were reviewed and approved by the

Westinghouse Owners Group Procedures Working Group.

21

7.0 APPLICATION TO PLANT-SPECIFIC VALIDATION

One of the initial objectives of the original ERG Revision 1 validation program

was to “document the validation program in such a manner that it might be

referenced by any plant writing EOPs based on the ERGs.” The SBCRG

validation program is considered to be an extension of the ERG program and

all plants writing a procedure employing the structure, format, and wording of

the SBCRG as a basis may reference the applicable results in this report as

well as the ERG Revision 1, Revision 1A, Revision 1B, Revision 1C and

ARG-3 Revision 0 Validation Reports (References 1, 14, 15, 16 and 17).

The results of the SBCRG validation program are presented below:

1) The principle of USABILITY has been demonstrated on a generic basis.

It remains to be demonstrated by an individual plant that plant-specific

additions or modifications to the reference SBCRG do not detract from

the original usability.

2) The principle of OPERATIONAL CORRECTNESS has also been

demonstrated for the reference plant. The overall technical accuracy of

SBCRG is applicable to all plants providing that design differences from

the reference plant are properly addressed.

The compatibility of any procedure based on SBCRG with shift manning and

policy must be demonstrated on an individual plant basis.

22

8.0 REFERENCES

1. Emergency Response Guidelines Validation Program - Final Report

WCAP-10599, June 1984

2. Emergency Operating Procedures Validation Guidelines, INPO 83-006,

July 1983

3. Component Verification and System Validation Guideline, INPO 83-024,

December 1983 (NUTAC)

4. Emergency Operating Procedures Verification Guideline, INPO 83-004,

March 1983

5. Westinghouse Owners Group Emergency Response Guidelines -

Revision 1 Users Guide, September 1, 1983


Revision 1C, September 30, 1997


Revision 1A Writers Guide, July 1, 1987, as modified through Revision 1C


Revision 1 Reference Plant Description, September 1, 1983, as modified

through Revision 1C


Revision 1 Background Documents, September 1, 1983, as modified

through Revision 1C

23


Revision 1 Generic Issues, September 1, 1983, as modified through

Revision 1C

11. Emergency Response Guidelines Maintenance Summary Program

Summary Report, January 20, 1986, as modified through March 15, 2003


Revision 1A, Configuration Control, July 1, 1987, as modified through

Revision 1C

13. Emergency Response Guidelines Revision 1A Validation Report

WCAP 11638, October 1987

14. Emergency Response Guidelines Revision 1B Validation Report

WCAP 13236, May 1992

15. Emergency Response Guidelines Revision 1C Validation Report

WCAP 14973, September 1997

16. Abnormal Response Guideline ARG-3, Steam Generator Tube Leak

Revision 0 Validation Report WCAP 15917, July 2002

APPENDIX A

DEFINITIONS AND ABBREVIATIONS

A-1

APPENDIX A

DEFINITIONS

Abnormal Response Guidelines (ARG) - Detailed guidelines which are specifically

intended to respond to an abnormal plant condition when the ERGs are not

applicable.

Control Room Simulator - Dynamic device which imitates functions of control room

hardware in real, fast or slowed time.

Emergency Operating Procedures (EOPs) - Plant procedures directing the operator

actions to mitigate consequences of transients and accidents that cause plant

parameters to exceed reactor protection setpoints, engineered safety feature

setpoints, or other appropriate technical limits.

Emergency Response Guideline (ERG) - A complex and detailed network of generic

emergency guidance for W plants.

Function Restoration Guideline (FRG) - Those sets of operator action steps which

are specifically intended to respond to a Critical Safety Function challenge as

determined by plant symptoms.

Optimal Recovery Guideline (ORG) - Those sets of operator action steps in the

ERG network which respond to a specific, diagnosed event. Guidance is provided

to recover the plant from the event in the most efficient manner.

Reference Validation - Method of validation whereby data developed in a common

EOP validation program is referenced by similar plants.

(Critical) Safety Functions - A limited set of plant functions which, if maintained, will

prevent core damage and/or radioactivity release to the environment. An activity

which assures the integrity of the physical barriers against radiation release.

A-2

Status Tree - Graphical device to quickly evaluate the condition of a Critical Safety

Function. Identifies off-normal conditions and the appropriate FRG for restoration

of the function.

Symptoms - Displayed plant characteristics which directly or indirectly indicate plant

status.

System Operational Correctness - A characteristic of the System which indicates

the degree to which the components are compatible.

Table-Top - Method of validation whereby an operating crew explains their step-by-

step actions during a proposed event scenario to an observer/review team.

Verification - The evaluation performed to ensure consistency between any system

element and its appropriate source documents.

Walk-Through - Method of validation whereby an operating crew conducts a step-

by-step enactment of their actions during a proposed event scenario without

carrying out the actual control functions.

Westinghouse Owners Group (WOG) - Organization of utilities which own nuclear

power plants with Westinghouse-supplied Nuclear Steam Supply Systems.

Activities involve generic engineering, licensing, and operational issues relating to

Westinghouse-designed nuclear units.

Writers Guide of EOPs - A plant document that provides instructions for writing

EOPs, emphasizing the incorporation of good writing principles.

A-3

APPENDIX A

ABBREVIAITONS

AC - alternating current

AER - action/expected response

AFW - auxiliary feedwater

ARG - abnormal response guideline

ATWS - anticipated transient without scram

BIT - boric acid injection tank

BOL - beginning of life

CCP - centrifugal charging pump

CCW - component cooling water

CST - condensate storage tank

CTMT - containment

CVCS - chemical and volume control system

DBA - design basis accident

DG - diesel generator

ECCS - emergency core cooling system

ECR - emergency coolant recirculation

EOL - end of life

EOPs - emergency operating procedures

ERGs - emergency response guidelines

FRG - function restoration guideline

FSAR - final safety analysis report

FW - feedwater

GPM - gallons per minute

HHSI - high-head safety injection

HP - high pressure

LOCA - loss-of coolant accident

MD - motor driven

MSIV - main steam isolation valve

NIS - nuclear instrumentation system

A-4

NR - narrow range

NRC - Nuclear Regulatory Commission

ORG - optimal recovery guideline

PD - positive displacement

PORV - power operated relief valve

PPM - parts per million

PRT - pressure relief tank

PRZR - pressurizer

PSID - pounds per square inch differential

PSIG - pounds per square inch gauge

PTS - pressurized thermal shock

RCP - reactor coolant pump

RCS - reactor coolant system

RHR - residual heat removal

RNO - response not obtained

RO - reactor operator

RVLIS - reactor vessel level indication system

RWST - refueling water storage tank

SG - steam generator

SGTR - steam generator tube rupture

SI - safety injection

SRO - senior reactor operator

STA - shift technical advisor

TAVG - average temperature

TCOLD - cold leg temperature

TCs - thermocouples

THOT - hot leg temperature

VCT - volume control tank

WOG - Westinghouse Owners Group

WR - wide range

APPENDIX B

SBCRG (GENERIC GUIDELINE AS OF DATE OF VALIDATION)

Number SBCRG

Title SUMP BLOCKAGE CONTROL ROOM GUIDELINE

Rev./Date Draft 01/21

SBCRG 1 of 19

A. PURPOSE This guideline provides actions to protect SI pumps and spray pumps from damage caused by loss of suction, to reduce flow through the recirculation sump, to re-establish injection flow to the RCS and to depressurize the RCS to minimize break flow.

B. SYMPTOMS AND ENTRY CONDITIONS This guideline is entered from: 1) ES-1.3, TRANSFER TO COLD LEG RECIRCULATION, Step 5 when symptoms of

recirculation sump blockage are indicated. 2) ECA-1.1, LOSS OF EMERGENCY COOLANT RECIRCULATION, Step 1 when

symptoms of recirculation blockage are indicated..

Number SBCRG



STEP ACTION/EXPECTED RESPONSE RESPONSE NOT OBTAINED

SBCRG 2 of 19

CAUTION • Any pump receiving suction from a low-head SI pump should be stopped before stopping the low-head SI pump.

• If suction source is lost to any SI or spray pump, the pump should be stopped.

*1 Monitor Low-Head SI Pump Suction Conditions – NO INDICATION OF CAVITATION [Enter plant-specific means]

1. Perform the following: a. Stop any containment spray

pump(s) taking suction from sump.

b. IF indications of cavitation continue, THEN reduce flow using RHR flow control valve(s) until cavitation stops.

c. IF indications of cavitation continue, THEN close associated RHR injection isolation valve(s).

d. IF indications of cavitation continue, THEN perform the following: 1) Stop any charging/SI

pump(s) and high-head SI pump(s) supplied from affected low-head SI pump(s).

2) Stop affected low-head SI pump(s).

2 Verify Containment Fan Coolers - RUNNING IN EMERGENCY MODE

Manually start fan coolers in emergency mode.

*3 Monitor RWST Level – GREATER THAN (U.03)

Stop pumps taking suction from RWST.

Number SBCRG




SBCRG 3 of 19

NOTE Whenever possible, containment spray pumps should be aligned to take suction from sources separate from running SI pumps.

4 Determine Containment Spray Requirements With Suction From RWST:

a. RWST level – GREATER THAN (U.03)

a. Go to step 5.

b. Spray pump suction – ALIGNED TO RWST

b. Go to step 5.

c. Determine number of spray pumps required from table:

CONTAINMENT PRESSURE

FAN COOLERS RUNNING IN EMERGENCY

MODE

SPRAY PUMPS

REQUIRED

(T.09) 1 GREATER THAN (T.02) PSIG

ALL 0

LESS THAN (T.02) PSIG ----- 0

d. Spray pumps running – EQUAL TO NUMBER REQUIRED

c. Manually operate pumps as necessary.

Number SBCRG




SBCRG 4 of 19

5 Establish SI Recirculation Suction:

a. Any low-head SI pump – RUNNING WITH SUCTION FROM SUMP

a. Perform the following:

1) Stop any spray pump taking suction from sump.

2) Close RHR injection isolation and flow control valve(s).

3) Start one low-head SI pump.

4) IF indications of cavitation occur, THEN stop the running pump AND start the other low-head SI pump.

5) IF indications of cavitation continue, THEN stop the running pump AND go to Step 8.

b. Start or stop low-head SI pumps to obtain only one pump running

Number SBCRG




SBCRG 5 of 19

CAUTION: A low-head SI pump stopped because of cavitation in the previous step should not be restarted in this step..

6 Establish Low-Head SI Recirculation Flow:

a. RCS pressure – LESS THAN (B.07) PSIG [(B.08) PSIG FOR ADVERSE CONTAINMENT]

a. Go to Step 7.

b. Perform the following:

1) Open low-head SI injection isolation valves.

2) Manually adjust flow control valves to establish indication of low-head SI injection flow without cavitation

b. IF indications of cavitation occur with flow control valve closed, THEN perform the following:

1) Stop the running low-head SI pump.

2) Start the other low-head SI pump.

3) IF no low-head SI pump will operate without cavitation, THEN stop any running SI pump AND go to Step 8.

4) Manually adjust flow control valve to establish low-head SI injection flow without indication of cavitation.

5) IF indications of cavitation occur with flow control valve closed, THEN stop the running low-head SI pump and go to Step 8.

IF a pump is running but no indication of injection flow can be established, THEN go to Step 7.

b. Go to Step 9

Number SBCRG




SBCRG 6 of 19

7 Establish High-Head ECCS In Recirculation Mode:

a. High-head SI pump and charging/SI pump - SUCTIONS ALIGNED TO RUNNING LOW-HEAD SI PUMP

a. Align high-head SI pump and charging/SI pump suctions to running low-head SI pump. [enter plant-specific means]

b. High-head SI pumps and charging/SI pumps – ONLY ONE RUNNING

b. Start or stop high-head SI pumps and charging/SI pumps to obtain one high-head SI pump or charging/SI pump running in recirculation alignment.

c. High-head SI pump or charging/SI pump – RUNNING IN RECIRCULATION ALIGNMENT

c. Go to Step 8.

d. Go to step 9

8 Establish High-Head ECCS With Suction From RWST:

a. Check RWST level – GREATER THAN (U.03)

a. Go to Step 9.

b. Any high-head SI pump or charging/SI pump suction – ALIGNED TO RWST

b. Align high-head SI pump and charging/SI pump suctions to RWST.

c. Start or stop high-head SI pumps and charging/SI pumps to obtain one running with suction from RWST

9 Check If Containment Spray Should Be

Aligned For Recirculation:

a. Recirculation sump level – GREATER THAN (T.08)

a. Continue with Step 11. WHEN recirculation sump level greater than (T.08), THEN do Steps 9b and 10.

b. Align spray for recirculation: [Enter plant-specific means]

Number SBCRG




SBCRG 7 of 19

CAUTION: If running a spray pump causes indications of cavitation for a SI pump, the spray pump should be stopped immediately.


10 Determine Spray Requirements With Suction From Recirculation Sump:

a. Determine number of spray pumps required from table:

CONTAINMENT PRESSURE FAN COOLERS

RUNNING IN EMERGENCY MODE

SPRAY PUMPS

REQUIRED

(T.09) 1 GREATER THAN (T.02) PSIG

ALL 0

LESS THAN (T.02) PSIG ----- 0 b. Spray pumps running - EQUAL TO

NUMBER REQUIRED b. Manually operate spray pumps as

necessary.

11 Notify Plant Engineering Staff To Evaluate Optimum SI And Spray Alignment

12 Verify No Backflow From RWST To Sump:

a. Sump recirculation valves – ANY OPEN

a. IF both sump recirculation valves closed, THEN go to Step 13.

b. Valve from RWST to low-head SI pump in same train – CLOSED

b. Manually close valve(s).

13 Add Makeup To RWST As Necessary:

[Enter plant-specific means]

Number SBCRG




SBCRG 8 of 19

NOTE Before starting any pump with suction aligned to low-head SI pumps, adequate suction path should be ensured.

*14 Monitor For Adequate RCS Makeup Flow:

a. Check RVLIS indication:

• Full range - GREATER THAN (K.02) IF NO RCP RUNNING

-OR- • Dynamic head range - GREATER

THAN (L.08) IF ONE RCP RUNNING

a. Increase RCS makeup flow to maintain RVLIS indication as necessary.

IF RVLIS indication can NOT be maintained, THEN try to add makeup to RCS from alternate source.

[Enter plant-specific means].

b. Core exit TCs - STABLE OR DECREASING

b. Increase RCS makeup flow to maintain TCs stable or decreasing.

IF TC indication can NOT be maintained, THEN try to add makeup to RCS from alternate source.


15 Check For RCS Makeup Capability:

• Charging/SI pump flow indicators – FLOW INDICATED - OR –

• High-head SI pump flow indicators – FLOW INDICATED - OR –

• Low-head SI pump flow indicators – FLOW INDICATED

Go to Step 33.

Number SBCRG




SBCRG 9 of 19

CAUTION Alternate water sources for AFW pumps will be necessary if CST level decreases to less than (U.01).

*16 Check Intact SG Levels: a. Narrow range level - GREATER THAN

(M.02)% [(M.03)% FOR ADVERSE CONTAINMENT]

a. Maintain total feed flow greater than (S.02) gpm until narrow range level greater than (M.02)% [(M.03)% for adverse containment] in at least one SG.

b. Control feed flow to maintain narrow range level between (M.02)% [(M.03)% for adverse containment] and 50%

b. IF narrow range level in any SG continues to increase, THEN stop feed flow to that SG.

NOTE • Shutdown margin should be monitored during RCS cooldown.

• Low steamline pressure SI signal should be blocked when PRZR pressure decreases to less than (A.05) psig.

• After the low steamline pressure SI signal is blocked, main steamline isolation will occur if the high steam pressure rate setpoint is exceeded.

17 Initiate RCS Cooldown To Cold Shutdown:

a. Maintain cooldown rate in RCS cold legs - LESS THAN 100°F/HR

b. Dump steam to condenser from intact SG(s)

b. Manually or locally dump steam from intact SG(s):

• Use PORV.

-OR-

• [Enter plant-specific means].

IF no intact SG available, THEN use faulted SG.

Number SBCRG




SBCRG 10 of 19

CAUTION If RCP seal cooling had previously been lost, the affected RCP(s) should not be started prior to a status evaluation.

NOTE RCPs should be run in order of priority to provide normal PRZR spray.

18 Check If An RCP Should Be Started:

a. All RCPs - STOPPED a. Stop RCP(s) NOT required for normal PRZR spray. Go to Step 19.

b. RCS subcooling based on core exit TCs - GREATER THAN (R.01)°F [(R.02)°F FOR ADVERSE CONTAINMENT]

b. Go to Step 19.

c. Try to start an RCP to provide normal PRZR spray:

1) Establish conditions for starting an RCP:

[Enter plant-specific list]

2) Start RCP in loop with surge line

c. IF RCP in loop with surge line can NOT be started, THEN try to start other RCP(s) as necessary to provide normal spray.

*19 Check If SI Can Be Terminated:



-OR-

• Dynamic head range - GREATER THAN (L.08) IF ONE RCP RUNNING

a. Go to Step 27.


b. Establish minimum SI flow to remove decay heat. Perform the following:

1) Determine minimum SI flow required from Figure ECA13-1.

2) Establish minimum SI flow.

3) Go to Step 27.

20 Reset Containment Isolation Phase A And Phase B

Number SBCRG




SBCRG 11 of 19

21 Establish Instrument Air To Containment

Start one air compressor and establish instrument air to containment.

22 Stop Running High-Head SI Pump And Place In Standby

23 Isolate BIT:

a. Check charging/SI pump miniflow isolation valves - OPEN

a. Manually open valves.

b. Close BIT inlet isolation valves

c. Close BIT outlet isolation valves

24 Establish Charging Flow:

a. Close charging line hand control valve

b. Open charging line isolation valves

c. Establish desired charging flow using charging flow control valve and charging line hand control valve

25 Check If Charging/SI Pump Can Be Realigned To RWST:

a. RWST level – GREATER THAN (U.03)

a. Go to Step 27.

b. RWST refill rate – GREATER THAN CHARGING FLOW RATE

b. Go to Step 27.

c. Open charging/SI pump suction valves from RWST

d. Close charging/SI pump suction valves from low-head SI pump

26 Stop Running Low-head SI Pump And Place In Standby

Number SBCRG




SBCRG 12 of 19

NOTE Before starting any pump with suction aligned to low-head SI pumps, adequate suction path should be ensured.

*27 Monitor Need For Additional RCS Makeup Flow:



-OR-


a. Increase RCS makeup flow to maintain RVLIS indication as necessary.

IF RVLIS indication can NOT be maintained, THEN try to add makeup to RCS from alternate source.



b. Increase RCS makeup flow to maintain TCs stable or decreasing.

IF TC indication can NOT be maintained, THEN try to add makeup to RCS from alternate source.


Number SBCRG




SBCRG 13 of 19

NOTE The upper head region may void during RCS depressurization if RCPs are not running. This will result in a rapidly increasing PRZR level.

28 Depressurize RCS To Decrease RCS Subcooling:

a. RCS subcooling based on core exit TCs - GREATER THAN (R.08)°F [(R.09)°F FOR ADVERSE CONTAINMENT]

a. Go to Step 29.

b. Use normal PRZR spray b. Use one PRZR PORV. IF RCS can NOT be depressurized using any PRZR PORV, THEN use auxiliary spray.

c. Depressurize RCS until either of the following conditions satisfied:

• RCS subcooling based on core exit TCs - BETWEEN (R.01)°F [(R.02)°F FOR ADVERSE CONTAINMENT] AND (R.08)°F [(R.09)°F FOR ADVERSE CONTAINMENT]

-OR-

• PRZR level - GREATER THAN (D.08)% [(D.09)% FOR ADVERSE CONTAINMENT]

c. IF RCS subcooling less than (R.01)°F [(R.02)°F for adverse containment], THEN increase RCS makeup flow as necessary to restore subcooling.

d. Stop RCS depressurization

29 Check If RHR System Should Be Placed In Service:

a. Check the following:

• RCS temperature – LESS THAN (F.06)°F [(F.07)°F FOR ADVERSE CONTAINMENT]

• RCS pressure - LESS THAN (B.01) PSIG [(B.02) PSIG FOR ADVERSE CONTAINMENT]

a. Go to Step 30.

b. Consult plant engineering staff to determine if RHR System should be placed in service

Number SBCRG




SBCRG 14 of 19

30 Check If SI Accumulators Should Be Isolated:

a. At least two RCS hot leg temperatures - LESS THAN (F.05)°F

a. Continue with Step 31. WHEN at least two RCS hot leg temperatures less than (F.05)°F, THEN do Steps 30.b and c.

b. Check power to isolation valves - AVAILABLE

b. Restore power to isolation valves.

c. Close all SI accumulator isolation valves

c. Vent any unisolated accumulators. IF an accumulator can NOT be isolated or vented, THEN consult the plant engineering staff to determine contingency actions.

*31 Check If RCPs Must Be Stopped:


• Number 1 seal differential pressure - LESS THAN (W.01) PSID

-OR-

• Number 1 seal leakoff flow - LESS THAN (W.02) GPM

a. IF neither condition satisfied, THEN go to Step 32.

b. Stop affected RCP(s)

32 Check RCS Temperature - GREATER THAN 200°F

Go to Step 40.

33 Try To Add Makeup To RCS From Alternate Source:


Number SBCRG




SBCRG 15 of 19

34 Check If Cooldown Rate Is Adequate:

a. RVLIS indication:

• Full range – GREATER THAN (K.02) IF NO RCP RUNNING

- OR –

• Dynamic head range – GREATER THAN (L.08) IF ONE RCP RUNNING

a. Go to Step 35.

b. Core exit TCs – STABLE OR DECREASING

b. Go to Step 35.

c. Return to Step 16

35 Check If All Intact SGs Should Be Depressurized To (O.06) PSIG:

a. Check SG pressures - GREATER THAN (O.06) PSIG

a. Go to Step 36.

b. Dump steam to condenser at maximum rate

b. Manually or locally dump steam at maximum rate from intact SG(s):

• Use PORV.

-OR-


c. Check SG pressures – LESS THAN (O.06) PSIG

c. Return to Step 35.b.

d. Stop SG depressurization

Number SBCRG




SBCRG 16 of 19

36 Depressurize All Intact SGs To Inject Accumulators As Necessary:

a. Dump steam to condenser as necessary to maintain appropriate RVLIS indication:

• Full range at (K.02) - IF NO RCP RUNNING

-OR-

• Dynamic head range at (L.08) - IF ONE RCP RUNNING

a. Manually or locally dump steam from intact SG(s) as necessary to maintain appropriate RVLIS indication:

• Use PORV.

-OR-


b. Check SG pressures – LESS THAN (O.07) PSIG

b. Return to Step 36.a.

c. Stop SG depressurization



a. Continue with Step 38. WHEN at least two RCS hot leg temperatures less than (F.05)°F, THEN do Steps 37.b and c.








-OR-




Number SBCRG




SBCRG 17 of 19

39 Depressurize All Intact SGs To Atmospheric Pressure:

a. Maintain cooldown rate in RCS cold legs – LESS THAN 100°F/HR

b. Dump steam to condenser b. Manually or locally dump steam from intact SG(s):

• Use PORV.

-OR-


40 Check Core Exit TCs – LESS THAN 1200oF

IF core exit temperatures greater than 1200oF and increasing, THEN go to SACRG-1, SEVERE ACCIDENT CONTROL ROOM GUIDELINE INITIAL RESPONSE, Step 1.





a. Return to Step 39.


Number SBCRG




SBCRG 18 of 19

*42 Maintain RCS Heat Removal:

a. Use RHR System if in service

b. Dump steam to condenser from intact SGs

b. Manually or locally dump steam from intact SGs:

• Use PORV.

-OR-


IF no intact SG available and RHR system NOT in service, THEN use faulted SG.

43 Check Containment Hydrogen Concentration:

a. Obtain a hydrogen concentration measurement:


b. Hydrogen concentration - LESS THAN (T.05)% IN DRY AIR

b. Consult plant engineering staff for additional recovery actions. Go to Step 44.

c. Hydrogen concentration - LESS THAN 0.5% IN DRY AIR

c. Turn on hydrogen recombiner system.

44 Consult Plant Engineering Staff

– END –

Number SBCRG



SBCRG 19 of 19

0

100

200

300

400

500

600

10 100 1000 10000Time (Minutes)

Flo

w R

ate

(GP

M) EXAMPLE

ONLY

FIGURE ECA11-1. MINIMUM SI FLOW RATE VERSUS TIME AFTER TRIP

APPENDIX C

SHEARON HARRIS VALIDATION COPY OF SBCRG

WESTINGHOUSE OWNERS GROUP

VALIDATION TEST

AT SHEARON HARRIS SIMULATOR

SBCRG

SUMP BLOCKAGE CONTROL ROOM GUIDELINE

Validation

01/29/2004

Number SBCRG


Rev./Date Validation 01/29/2004

1 of 36 1/29/04

A. PURPOSE This guideline provides actions to protect SI pumps and spray pumps from damage caused by loss of suction, to reduce flow through the recirculation sump, to re-establish injection flow to the RCS and to depressurize the RCS to minimize break flow.

B. SYMPTOMS AND ENTRY CONDITIONS This guideline is entered from: 1) ES-1.3, TRANSFER TO COLD LEG RECIRCULATION, when symptoms of

recirculation sump blockage are indicated. 2) ECA-1.1, LOSS OF EMERGENCY COOLANT RECIRCULATION, when symptoms

of recirculation blockage are indicated..

Number SBCRG




2 of 36 1/29/04

CAUTION • Any pump receiving suction from an RHR pump should be stopped before stopping the RHR pump.

• If suction source is lost to any SI or spray pump, the pump

should be stopped.

1 Monitor RHR Pump Suction Conditions – NO INDICATION OF CAVITATION

Perform the following:

a. Stop any containment spray pump(s) taking suction from sump.

b. IF indications of cavitation

continue, THEN reduce flow using RHR flow control valve(s) until cavitation stops.

1RH-30 (HC-603A1) 1RH-20 (FK-605A1) 1RH-66 (HC-603B1) 1RH-58 (FK-605B1) c. IF indications of cavitation

continue, THEN close associated RHR injection isolation valve(s).

1SI-340 1SI-341 1SI-326 1SI-327 1SI-359 d. IF indications of cavitation

continue, THEN perform the following:

1) Stop any CSIPs supplied

from affected RHR pump(s).

2) Stop affected RHR

pump(s).

Number SBCRG




3 of 36 1/29/04

2 Verify Containment Fan Coolers -

ONE FAN PER UNIT RUNNING IN SLOW SPEED

Manually start fan coolers.

3 Monitor RWST Level – GREATER

THAN 3% (Empty Alarm) Stop pumps taking suction from

RWST.

Number SBCRG




4 of 36 1/29/04


4 Determine Containment Spray Requirements With Suction From RWST:

a. RWST level – GREATER THAN 3%

a. Go to Step 5.

b. Spray pump suction – ALIGNED TO RWST

b. Go to Step 5.

c. Determine number of spray pumps

required from table:

CONTAINMENT PRESSUREFAN COOLER UNITS

RUNNINGCNMT SPRAY

PUMPS REQUIRED

LESS THAN 2 1

2 OR MORE 0

LESS THAN 10 PSIG N/A 0

GREATER THAN 10 PSIG

d. Spray pumps running – EQUAL TO NUMBER REQUIRED

d. Manually operate pumps as necessary.

1) Reset CNMT spray signal if

necessary 2) Align CNMT spray pump(s)

stopped in this Step for standby operation: o Shut CNMT spray pump

discharge valve(s): 1CT-50 (A CT Pump) 1CT-88 (B CT Pump) o Shut chemical addition

valve(s) 1CT-12 (a CT Pump) 1CT-11 (B CT Pump)

Number SBCRG




5 of 36 1/29/04

5 Establish SI Recirculation Suction:

a. Any RHR pump – RUNNING WITH SUCTION FROM SUMP


1) Stop any spray pump taking suction from sump.

2) Close RHR injection isolation

and flow control valve(s). 1SI-340 1SI-341 1SI-326 1SI-327 1SI-359 1RH-30 (HC-603A1) 1RH-20 (FK-605A1) 1RH-66 (HC-603B1) 1RH-58 (FK-605B1) 3) Start one RHR pump. 4) IF indications of cavitation

occur, THEN stop the running pump AND start the other RHR pump.

5) IF indications of cavitation

continue, THEN stop the running pump AND go to Step 8.

b. Start or stop RHR pumps to obtain only one pump running

Number SBCRG




6 of 36 1/29/04

CAUTION An RHR pump stopped because of cavitation in the previous step should not be restarted in this step.

6 Establish RHR Recirculation Flow:

a. RCS pressure – LESS THAN 230 PSIG

a. Go to Step 7.


1) Open RHR injection isolation valves.

1SI-340 1SI-341 2) Manually adjust flow control

valves to establish indication of RHR injection flow without cavitation

1RH-30 (HC-603A1) 1RH-20 (FK-605A1) 1RH-66 (HC-603B1) 1RH-58 (FK-605B1)


1) Stop the running RHR pump.

2) Start the other RHR pump.

3) IF no RHR pump will operate without cavitation, THEN stop any running SI pump AND go to Step 8.

4) Manually adjust flow control valve to establish RHR injection flow without indication of cavitation.

5) IF indications of cavitation occur with flow control valve closed, THEN stop the running RHR pump and go to Step 8.


c. Go to Step 9

Number SBCRG




7 of 36 1/29/04

7 Establish High-Head ECCS In Recirculation Mode:

a. CSIPs - SUCTIONS ALIGNED TO RUNNING RHR PUMP

a. Align CSIP suctions to running RHR pump.

"A" RHR: 1RH-25 "B" RHR: 1RH-63

b. CSIPs – ONLY ONE RUNNING b. Start or stop CSIPs to obtain one CSIP running in recirculation alignment.

c. CSIP – RUNNING IN

RECIRCULATION ALIGNMENT

c. Go to Step 8.

d. Go to step 9 8 Establish High-Head ECCS With

Suction From RWST:

a. Check RWST level – GREATER THAN 3%

a. Go to Step 9.

b. Any CSIP suction – ALIGNED TO RWST

b. Align CSIP suctions to RWST. (Refer to EOP-EPP-010,

Attachment 2).

c. Start or stop CSIPs to obtain one running with suction from RWST

Number SBCRG




8 of 36 1/29/04

9 Check If Containment Spray Should Be Aligned For Recirculation:

a. Check CNMT wide range sump level - GREATER THAN 137.5 INCHES

a. WHEN level greater than 137.5 INCHES, THEN do Steps 9b and 10.

Continue with Step 11.

b. Align CNMT spray for recirculation:

1) Open CNMT spray pump suction valves:

1CT-102 1CT-105 2) Shut RWST to CNMT spray

pump suction valves: 1CT-26 1CT-71

Number SBCRG




9 of 36 1/29/04

CAUTION If running a spray pump causes indications of cavitation for a SI pump, the spray pump should be stopped immediately.

NOTE Whenever possible, containment spray pumps should be aligned to

take suction from sources separate from running SI pumps.

10 Determine Spray Requirements With Suction From Recirculation Sump:

a. Determine number of spray pumps required from table:

CONTAINMENT PRESSUREFAN COOLER UNITS

RUNNINGCNMT SPRAY

PUMPS REQUIRED

LESS THAN 2 1

2 OR MORE 0

LESS THAN 10 PSIG N/A 0

GREATER THAN 10 PSIG

b. Spray pumps running - EQUAL TO NUMBER REQUIRED

b. Manually operate pumps as necessary.

1) Reset CNMT spray signal if

necessary 2) Align CNMT spray pump(s)

stopped in this Step for standby operation:

o Shut CNMT spray pump

discharge valve(s): 1CT-50 (A CT Pump) 1CT-88 (B CT Pump) o Shut chemical addition

valve(s) 1CT-12 (a CT Pump) 1CT-11 (B CT Pump)

Number SBCRG




10 of 36 1/29/04

11 Notify Plant Operations Staff To Evaluate Optimum SI And Spray Alignment

Number SBCRG




11 of 36 1/29/04

12 Verify No Backflow From RWST To Sump:

a. Check sump recirculation valve – OPEN

1CT-105

a. Go to Step 12c.

b. Verify RWST suction valve – SHUT 1CT-26

b. Manually close valve.

c. Check sump recirculation valve – OPEN

1CT-102

c. Go to Step 12e.

d. Verify RWST suction valve – SHUT 1CT-71

d. Manually close valve.

e. Check both of the following sump recirculation valves - OPEN

1SI-300 1SI-310

e. Go to Step 12g.

f. Verify RWST suction valve – SHUT 1SI-322

f. Manually close valve.

g. Check both of the following sump recirculation valves - OPEN

1SI-301 1SI-311

g. Go to Step 13.

h. Verify RWST suction valve – SHUT 1SI-323

h. Manually close valve.

Number SBCRG




12 of 36 1/29/04

13 Add Makeup To RWST As Necessary: • Add Makeup to RWST Using OP-

107, "CHEMICAL AND VOLUME CONTROL SYSTEM", SECTION 8.7

Consult plant operations staff for alternate makeup sources.

NOTE Before starting any pump with suction aligned to RHR pumps,

adequate suction path should be ensured.

14 Monitor For Adequate RCS Makeup Flow:


o Full range - GREATER THAN 63% IF NO RCP RUNNING

-OR-

o Dynamic head range - GREATER THAN 34% IF ONE RCP RUNNING

a. Increase RCS makeup flow to maintain RVLIS indication as necessary using Attachment 2.

IF RVLIS indication can NOT be

maintained, THEN try to add makeup to RCS from alternate source. Consult plant operations staff.


b. Increase RCS makeup flow to maintain TCs stable or decreasing using Attachment 2.

IF TC indication can NOT be


Number SBCRG




13 of 36 1/29/04

15 Check For RCS Makeup Capability: • SI flow indicators – FLOW

INDICATED - OR –

• RHR pump flow indicators – FLOW INDICATED

Go to Step 36.

CAUTION Alternate water sources for AFW pumps will be necessary if CST

level decreases to less than 10% .

16 Check Intact SG Levels:

a. Any level - GREATER THAN 25% [40%]

a. Maintain total feed flow greater than 210 KPPH until level greater than 25% [40%] in at least one intact SG.

b. Control feed flow to maintain all

intact leve ls between 25% and 50% [40% and 50%]

b. IF level in any SG continues to increase, THEN stop feed flow to that SG.

NOTE After the low steamline pressure SI signal is blocked, main

steamline isolation will occur if the high steam pressure rate setpoint is exceeded.

17 Check PRZ Pressure

a. Pressure - LESS THAN 2000 PSIG

a. When PRZ pressure less than 2000 PSIG, THEN block low steam pressure SI.

Observe CAUTION prior to

Step 18 and continue with Step 18.

b. Block low steam pressure SI

Number SBCRG




14 of 36 1/29/04

CAUTION The RCS cooldown should be performed as quickly as possible to minimize potential offsite releases.

18 Initiate RCS Cooldown To Cold

Shutdown:


b. Check SGs - AT LEAST ONE INTACT SG AVAILABLE

b. Dump steam from faulted SGs.

Go to Step 19.

c. Check if steam dump to condenser

- AVAILABLE:

o Check any intact SG MSIV - OPEN

o Check condenser available

(C-9) light (BPLB 3-3) - LIT o Steam dump control system -

AVAILABLE

c. Dump steam from intact SGs using any of the following (listed in order of preference):

1) SG PORVs

2) Locally operate SG PORVs using OP-126, "MAIN STEAM, EXTRACTION STEAM, AND STEAM DUMP SYSTEMS", Section 8.2.

3) TDAFW pump

Go to Step 19.

d. Transfer steam dump to steam pressure mode using OP-126, "MAIN STEAM, EXTRACTION STEAM AND STEAM DUMP SYSTEM", Section 5.3

e. Dump steam from intact SGs to condenser using condenser steam dumps

Number SBCRG




15 of 36 1/29/04

19 Monitor Shutdown Margin While Continuing RCS Cooldown:

a. Coordinate with plant operations staff AND chemistry to perform the following to obtain primary and secondary samples:

1) Operate the primary AND

secondary sample panels 2) Open CCW to sample HX

valves: 1CC-114 1CC-115 3) Open CCW to GFFD valves: 1CC-304 1CC-305 4) Align AND obtain activity AND

boron samples of the following:

• RCS hot legs • All SGs (Refer to OP-101, "SAMPLING

SYSTEM", Section 5.0)

b. Determine boron required for shutdown margin for anticipated RCS temperatures

(Refer to OST-1036, "SHUTDOWN

MARGIN CALCULATION".)

c. Check RCS loop boron - GREATER THAN BORON REQUIRED FOR SHUTDOWN MARGIN

c. Consult plant operations staff concerning boration requirements while continuing with this procedure.

Number SBCRG




16 of 36 1/29/04

CAUTION Following a complete loss of seal cooling, the affected RCP(s) should NOT be started prior to a status evaluation.

NOTE RCPs should be run in order of priority (B,A,C) to provide normal

PRZ spray.

20 Check RCP Status:

a. RCS Subcooling - GREATER THAN

10°F [40°F] - C 20°F [50°F] - M

a. Stop all RCPs. Go to Step 21.

b. Check all RCPs - STOPPED b. Stop all but one RCP. Go to Step 21.

c. Establish support conditions AND start one RCP while continuing with this procedure:

1) Check all of the following - IN

SERVICE

o CCW to motor oil coolers o CCW to thermal barrier

HXs o Seal injection

2) Establish conditions for

running an RCP using OP-100, "REACTOR COOLANT SYSTEM", Section 8.11

3) Start one RCP using OP-100,

"REACTOR COOLANT SYSTEM", Section 8.12

1) Establish cooling to RCPs

using OP-100, "REACTOR COOLANT SYSTEM", Section 8.10 while continuing with this procedure.

Number SBCRG




17 of 36 1/29/04

21 Check SI Termination Criteria Using Both Of The Following:



-OR-


a. Go to Step 30.

b. RCS Subcooling - GREATER THAN

60°F [90°F] - C 70°F [100°F] - M

b. Go to Step 22.

c. Go to Step 23.

Number SBCRG




18 of 36 1/29/04

22 Establish Minimum SI Flow Needed To Remove Decay Heat:

a. Verify any CSIP - RUNNING

a. Go to Step 22c.

b. Stop RHR pump injection

c. Determine minimum SI flow from Attachment 1, "MINIMUM SI FLOW RATE VERSUS TIME AFTER REACTOR TRIP"

d. Check SI flow - GREATER THAN MINIMUM FOR DECAY HEAT REMOVAL

d. Go to Step 22f.

e. Go to Step 30

f. RCS pressure - LESS THAN 230 PSIG

f. Start CSIPs to establish SI flow greater than minimum for decay heat removal.

g. Start CSIPS AND RHR pumps to establish SI flow greater than minimum for decay heat removal

h. Go to Step 30

23 Reset Phase A And Phase B

Isolation Signals

Number SBCRG




19 of 36 1/29/04

24 Establish Instrument Air AND Nitrogen To Containment

a. Open the following valves: 1IA-819 1SI-287

a. Perform the following: 1) Verify air compressor 1A

AND 1B - IN LOCAL CONTROL MODE

(Refer to PATH-1 GUIDE,

Attachment 5.) 2) Establish instrument air AND

nitrogen to CNMT 25 Isolate High Head SI Flow:

a. Open normal miniflow isolation valves:

1CS-182 1CS-196 1CS-210 1CS-214

a. Observe NOTE prior to Step 26 AND go to Step 26.

b. Shut BIT outlet valves: 1SI-3 1SI-4

b. Locally shut OR isolate valves.

c. Verify cold leg AND hot leg injection valves - SHUT

1SI-52 1SI-86 1SI-107

c. Locally shut valves.

d. Observe CAUTION prior to Step 27 AND go to Step 27

d.

Number SBCRG




20 of 36 1/29/04

NOTE The following step contains an SI termination sequence for which CSIP normal miniflow is not available. The charging flow control valve is opened a minimal amount prior to isolating the BIT to ensure the running CSIP is not deadheaded.

26 Establish Minimum Charging Flow

AND Isolate BIT Flow:

a. Shut charging flow control valve: FK-122.1

b. Open charging line isolation valves: 1CS-235 1CS-238

c. Set charging flow controller demand position to 30%

d. Shut BIT outlet valves: 1SI-3 1SI-4

d. Locally shut OR isolate valves.

e. Verify cold leg AND hot leg injection valves - SHUT

1SI-52 1SI-86 1SI-107

e. Locally shut valves.

f. Establish and maintain at least 60 GPM flow through CSIP

g. Go to Step 30

Number SBCRG




21 of 36 1/29/04

CAUTION High head SI flow should be isolated before continuing.

27 Establish Charging Lineup:

a. Shut charging flow control valve: FK-122.1

b. Open charging line isolation valves: 1CS-235 1CS-238

c. Open charging flow control valve to establish charging flow:

FK-122.1

c. Locally perform the following: 1) Shut charging flow control

inlet isolation valve: 1CS-228 2) Control charging using

bypass flow control valve: 1CS-227

28 Check If The CSIPS Can Be

Realigned To RWST:

a. RWST level – GREATER THAN 3%

a. Go to Step 30.


b. Go to Step 30.

c. Open CSIP suction valves from RWST

d. Close CSIP suction valves from RHR pumps

29 Stop RHR Pumps

Number SBCRG




22 of 36 1/29/04

NOTE Before starting any pump with suction aligned to RHR pumps, adequate suction path should be ensured.

30 Monitor Need For Additional RCS

Makeup Flow:



-OR-


a. Increase RCS makeup flow to maintain RVLIS indication as necessary using Attachment 2.

IF RVLIS indication can NOT be



b. Increase RCS makeup flow to maintain TCs stable or decreasing using Attachment 2.

IF TC indication can NOT be


Number SBCRG




23 of 36 1/29/04

CAUTION • Voiding may occur in the RCS during RCS depressurization. This will result in a rapidly increasing PRZ level.

• Charging or injection flow should NOT be increased if

subcooling is temporarily lost during RCS depressurization.


a. RCS Subcooling - GREATER THAN

10°F [40°F] - C 20°F [50°F] - M

a. Go to Step 32.

b. Depressurize the RCS until any of the following conditions occurs:

o RCS subcooling - BETWEEN 10°F AND 20°F - C [40°F AND 50°F] - C 20°F AND 30°F - M [50°F AND 60°F] -M

o PRZ level - GREATER THAN

75% [60%]

c. Use normal PRZ spray c. Depressurize using one of the following (listed in order of preference):

1) One PRZ PORV 2) IF SI is NOT in service,

THEN use auxiliary spray.

d. Check RCS Subcooling - GREATER THAN

10°F [40°F] - C 20°F [50°F] - M

d. Increase RCS makeup flow to restore subcooling

Attachment 2.

Number SBCRG




24 of 36 1/29/04

32 Check RHR System Status:

a. Check for both of the following:

o RCS hot leg temperature – LESS THAN 350°F [330°F]

o RCS pressure - LESS THAN

360 PSIG

a. Go to Step 33.

b. Consult plant operations staff to determine whether RHR System should be placed in service

c. RHR system - TO BE PLACED IN SERVICE

c. Go to Step 33.

d. Place RHR system in service using GP-007, "NORMAL PLANT COOLDOWN" AND OP-111, "RESIDUAL HEAT REMOVAL SYSTEM", Section 5.1.

Number SBCRG




25 of 36 1/29/04

33 Isolate SI Accumulators To Prevent Nitrogen Injection:

a. RCS hot leg temperatures - AT LEAST TWO LESS THAN 370°F

a. WHEN at least two RCS hot leg temperatures less than 370°F, THEN do Steps 33b, c and d.


b. Locally unlock AND close both breakers for each SI accumulator discharge valve:

1SI-246 (MCC-1A21-SA-5C) 1SI-247 (MCC-1B21-SB-5C) 1SI-248 (MCC-1A21-SA-3D)

c. Shut SI accumulator discharge valves:

1SI-246 1SI-247 1SI-248

c. Perform the following:

o Vent any unisolable accumulator using OP-110, "SAFETY INJECTION", Section 8.3.

o Maintain RCS pressure

greater than unisolable accumulator(s) pressure.

d. Locally open AND lock both

breakers for each SI accumulator discharge valve

Number SBCRG




26 of 36 1/29/04

34 Check If An RCP Should Be Stopped:

a. Check for any of the following:

o RCP #1 seal differential pressure - LESS THAN 200 PSID

o RCP #1 seal leakoff flow -

LESS THAN 0.2 GPM

a. IF any of the conditions occurs, THEN stop affected RCPs.


b. Stop affected RCPs 35 Check RCS Temperature -

GREATER THAN 200°F

Go to Step 43.

36 Establish Makeup To The RCS:

a. Verify makeup to RCS from alternate sources - AVAILABLE

o VCT (Refer to OP-107,

"CHEMICAL AND VOLUME CONTROL SYSTEM")

o PMS (Refer to OP-102,

"PRIMARY MAKE-UP SYSTEM")

o BRS (Refer to OP-109,

"BORON RECYCLE SYSTEM")

Locally de-energize control power to the CSIP 6.9 KV breakers: 1A-SA-CUB 5 (A CSIP) 1A-SA CUB 7 (C CSIP) 1B-SB CUB 4 (B CSIP) 1B-SB CUB 7 (C CSIP)

b. Add makeup to the RCS using alternate sources

Number SBCRG




27 of 36 1/29/04




-OR-


a. Go to Step 38.


b. Go to Step 38.


Number SBCRG




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38 Depressurize All Intact SGs:

a. Check SG pressures - GREATER THAN 690 PSIG

a. Go to Step 39.

b. Dump steam from intact SGs at maximum rate indication using any of the following (listed in order of preference):

1) Condenser steam dump 2) SG PORVs 3) Locally operate SG PORVs

using OP-126, "MAIN STEAM, EXTRACTION STEAM, AND STEAM DUMP SYSTEMS", Section 8.2

4) TDAFW pump

c. SG pressure – LESS THAN 690 PSIG

c. Return to Step 38b.

d. Stop SG depressurization AND stabilize SG pressure

Number SBCRG




29 of 36 1/29/04


a. Check RCPs - ALL STOPPED a. Maintain RVLIS dynamic range at 34%.

Go to Step 39c.

b. Maintain RVLIS full range at 63%

c. Dump steam to maintain RVLIS indication using any of the following (listed in order of preference):



4) TDAFW pump

d. SG pressure – LESS THAN 80 PSIG

d. Return to Step 39a.

e. Stop SG depressurization AND stabilize SG pressure

Number SBCRG




30 of 36 1/29/04

40 Isolate SI Accumulators To Prevent Nitrogen Injection:

a. RCS hot leg temperatures - AT LEAST TWO LESS THAN 370°F

a. WHEN at least two RCS hot leg temperatures less than 370°F, THEN do Steps 40b, c and d.


b. Locally unlock AND close both breakers for each SI accumulator discharge valve:

1SI-246 (MCC-1A21-SA-5C) 1SI-247 (MCC-1B21-SB-5C) 1SI-248 (MCC-1A21-SA-3D)

c. Shut SI accumulator discharge valves:

1SI-246 1SI-247 1SI-248


o Vent any unisolable accumulator using OP-110, "SAFETY INJECTION", Section 8.3.

o Maintain RCS pressure

greater than unisolable accumulator(s) pressure.

d. Locally open AND lock both

breakers for each SI accumulator discharge valve

Number SBCRG




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41 Check If An RCP Should Be Stopped:

a. Check for any of the following:

o RCP #1 seal differential pressure - LESS THAN 200 PSID

o RCP #1 seal leakoff flow -

LESS THAN 0.2 GPM

a. IF any of the conditions occurs, THEN stop affected RCPs.


b. Stop affected RCPs 42 Depressurize All Intact SGs To

Atmospheric Pressure:

a. Maintain RCS cooldown rate less than 100°F/HR

b. Dump steam from intact SGs using any of the following (listed in order of preference):



4) TDAFW pump

43 Check Core Exit TCs – LESS THAN

1200oF IF core exit temperatures greater than

1200oF and increasing, THEN go to SACRG-1, SEVERE ACCIDENT CONTROL ROOM GUIDELINE INITIAL RESPONSE, Step 1.

Number SBCRG




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44 Check RHR System Status:

a. Check for both of the following:

o RCS hot leg temperature – LESS THAN 350°F [330°F]

o RCS pressure - LESS THAN

360 PSIG


b. Consult plant operations staff to determine whether RHR System should be placed in service

c. RHR system - TO BE PLACED IN SERVICE

c. Go to Step 45.

d. Place RHR system in service using GP-007, "NORMAL PLANT COOLDOWN" AND OP-111, "RESIDUAL HEAT REMOVAL SYSTEM", Section 5.1.

Number SBCRG




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45 Maintain RCS Heat Removal:

a. Check RHR System - OPERATING IN SHUTDOWN COOLING MODE

a. Go to Step 45e.

b. Cooldown using RHR

c. Dump steam from intact SG(s) to supplement cooldown and cool SG(s) using any of the following (listed in order of preference):



4) TDAFW pump

d. Go to Step 46

e. Check SGs - AT LEAST ONE INTACT SG AVAILABLE

e. Dump steam using faulted SGs

f. Dump steam from intact SG(s) using any of the following (listed in order of preference):



4) TDAFW pump

Number SBCRG




34 of 36 1/29/04


a. Align Hydrogen Monitoring system using OP-125, "POST ACCIDENT HYDROGEN SYSTEM", Section 8.4

b. Obtain hydrogen concentration from any of the following:

o SPDS o Computer points ACM0700A ACM0700B o Locally at hydrogen control

panels

c. Hydrogen concentration - LESS THAN 4%


o Consult plant operations staff for additional recovery actions (including use of hydrogen purge).

o Evaluate EAL network using entry points T AND V.

o Continue monitoring hydrogen concentration.

Go to Step 47.

d. Hydrogen concentration - LESS THAN 0.5%

d. Energize hydrogen recombiners using OP-125, "POST ACCIDENT HYDROGEN SYSTEM", Section 5.0.

47 Consult Plant Operations Staff

– END –

Number SBCRG



35 of 36 1/29/04

ATTACHMENT 1 Sheet 1 of 1

MINIMUM SI FLOW RATE VERSUS TIME AFTER REACTOR TRIP

TIME AFTER REACTOR TRIP MINIMUM SI FLOW (GPM)

10 TO 15 MINUTES 500







1 TO 1.5 HOURS 300

1.5 TO 2 HOURS 275

2 TO 3 HOURS 250

3 TO 4 HOURS 225

GREATER THAN 4 HOURS 200

Number SBCRG



36 of 36 1/29/04

ATTACHMENT 2

Sheet 1 of 1 GUIDANCE ON INCREASING RCS MAKEUP FLOW

NOTE: This attachment provides guidance for increasing RCS makeup flow when

directed by procedure steps to restore RVLIS, core exit temperature or subcooling. The methods are listed in order of priority and include plant conditions required for effectiveness. (For example, to use RHR pumps the RCS must be below their shutoff head.)

• IF charging is in service (SI terminated), THEN increase charging flow. • IF charging flow can NOT restore the desired condition, THEN perform the following:

a. Shut charging line isolation valves AND open BIT valves.

b. Verify normal miniflow isolation valves - SHUT • IF one CSIP is in service in the injection mode, THEN start the standby CSIP. • IF all of the following conditions are met:

o All available CSIP are operating in the injection mode o RCS pressure is LESS THAN 230 PSIG

THEN restart RHR pumps in the low-head injection mode.

APPENDIX D

SBCRG VALIDATION

DISCREPANCY FORMS

FORM 2 DISCREPANCY FORM DISCREPANCY SHEET NUMBER 1-1

TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: ES-1.3 REV.: STEP NUMBER(S): N/A DISCREPANCY: Not clear that transition continues to apply after exiting ES-1.3 (EPP-10).

EVALUATOR: Date: 1-29-2004 RESOLUTION: Background document specifies this. Individual plant guidance must implement this.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1-7 DISCREPANCY: Strategy to restart pumps may not be effective plants where screen is not completely covered. Need additional guidance to deal with air entrainment.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Background document – individual plants need to evaluate susceptibility and possibility of venting.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SGCRG REV.: STEP NUMBER(S): 14,30 DISCREPANCY: What is objective for RVLIS? Is it sufficient to have level trending up, or must level be above setpoint to continue?

EVALUATOR: Date: 1-29-2004 RESOLUTION: Reword RNO to make intent clear. Intent is that upward trend is sufficient. Possibly relax level setpoint, document in background.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 14,30 DISCREPANCY: Increasing flow: If temperature is decreasing or steady, is this sufficient? Do we need both RVLIS and temperatures acceptable?

EVALUATOR: Date: 1-29-2004 RESOLUTION:

Retain both RVLIS and temperatures to maintain consistency with existing guidelines.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 14,30 DISCREPANCY: We put in a lot more injection flow than we really needed. Established ~100 gpm, (4000 gpm with RHR) needed by a few hundred gpm. [Done in accordance with Attachment 1]

EVALUATOR: Date: 1-29-2004 RESOLUTION: Use of Attachment 1 is a plant-specific issue. Reword guideline and state in Background Document that minimizing flow is an objective. * Added CAUTION preceding steps: SI recirculation flow should not be increased to a condition

that causes indication of SI pump cavitation.” * Background Document, section 3.1, High-Level Action Summary includes for “Establish and

Maintain Emergency Coolant Flow” describes the concept that optimum flow is that which supports critical safety functions at the lowest possible flow rates.

* Background Document, Step Description for Step 7 includes additional information on the intent to minimize flow (to no more than that needed to support safety functions).


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 13 DISCREPANCY: Should be adding makeup to RWST as soon as possible.

EVALUATOR: Date: 1-29-2004 RESOLUTION: COA-5 and COA-6 evaluate actions to makeup to the RWST before entering this guideline. First 10 steps – intended to protect pumps – are more urgent.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY X TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 6,7 DISCREPANCY: Injection alignment creates possibility of injecting to only one loop – this may be faulted loop. Any way to address this in procedure?

EVALUATOR: Date: 1-29-2004 RESOLUTION: Must be addressed on plant-specific basis if such an alignment is possible. Background document – specify intent to inject to all loops. Step Description for Step 7 includes this in the Basis.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1 (Note) DISCREPANCY: Need explicit statement that CSF status trees do not apply.


Added note preceding Step 1 addresses this concern. The Background Document describes the

basis of this note.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY X TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1 DISCREPANCY: Rather than reducing flow, close flow control values, then attempt to reopen. [On plant-specific basis, this may isolate recirculation.]


Preferred strategy is to reduce flow to (zero or minimum for recirculation flow), then re-open.

Step 1 modified to reflect this strategy. The Background Document Step Description for Step 1,

Basis, identifies the need to maintain pump cooling flow.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY X TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1 DISCREPANCY: Seems that step allows CSIPs to run while cavitating. May be better to stop all charging pumps, then try to restart. (Move RNO D1 to top of procedure.)


Accept suggestion.

Step 1, RNO 1) instructs the operator to stop any affected charging/SI pump. The second caution

preceding Step 1 also addresses this concern.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1 DISCREPANCY: Confusion of intent – Caution 2 implies immediate trip of RHR pumps. Step 1 directs other actions before tripping RHR pumps.


Change Step 1 Caution 2 to “charging/SI pump, high head SI pump” rather than “SI pump”.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: ES-1.3 REV.: STEP NUMBER(S): DISCREPANCY: Transition intent is not clear. Do we need caution of all ECCS pumps?


Clarify transition step(s) from ES-1.3, ECA-1.1.

SYMPTOMS AND ENTRY CONDITIONS for SBCRG identify conditions as, “indications of pump

cavitation caused by sump blockage prevent establishing or maintaining at least one train of

ECCS flow in the recirculation mode.

The Background Document Introduction provides additional detail on the intent of this transition.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 35 DISCREPANCY: Which temperatures are being checked? (Crew checked Cold Leg.) This appears to be a plant-specific issue of interface between standard wording of procedures and operator training.


Plant-specific issue. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 3 DISCREPANCY: Don’t like continuous action steps – prefer foldout page. This step should apply from the beginning.


Plant-specific issue to add foldout page. No changes to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) X WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 8 DISCREPANCY: EPP-10 Attachment 2 starts both pumps. Intent of guideline is to start only one.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Plant-specific issue: use of EPP10 Attachment 2 rather than (attachment) specifically for SBCRG. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: EPP-10 isolates non-essential CCW. Tripping CSIPs causes loss of all seal cooling. Restarting RCPs induces thermal shock on seals. Do we want to restore easy on isolate seal injection? (not a primary concern)

EVALUATOR: Date: 1-29-2004 RESOLUTION: Plant-specific issue. Integrity of RCP seals is negligible in these circumstances. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 19 DISCREPANCY: Plant-specific: need additional steps to establishing sampling.




TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY X TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6 DISCREPANCY: b. 2) incorrect valve #’s




TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 14,30 DISCREPANCY: Need to make clear need for any alternate source. Operators identified normal markup and charging. [This is in Step 36. [Step 35 used incorrectly] Guidance not specific for CET vs. cold leg]. Plant specific




TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: Ensure Step 36 is performed if no pumps are running. [Is Step 15 continuous action?] Longer-scale issue – what to do at any time in guideline if all flow is lost (including unique alignments).

EVALUATOR: Date: 1-29-2004 RESOLUTION: Step 15 is a continuous action step. Provide mechanism to repeat actions of first ten steps if all flow is lost. Step 13 (as modified in latest generic version) provides this mechanism. Strengthen Step 11 to determine optimum alignment for extreme circumstances. Background Document Step Description for Step 9 identifies the need to continually reevaluate pump operation. It also describes the need for operators to implement strategies to establish and maintain makeup flow to the RCS.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 43 DISCREPANCY: This transition seems to be buried at end. Would it be performed in a timely manner? Include in backup ?? (on in Q&A) Should this be continuous action step after reaching the step for the first time. No small loop.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Location is correct. Background Document addresses the reason for this location as a Frequently Asked Question/Answer. Step should not be continuous action: it is an element of a small loop.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 18 DISCREPANCY: Depressurize SGs as soon as possible and at the maximum achievable rate. To some safe level WRT PTS. Regardless of 100ºF/hour.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Accelerated cooldown provides no significant benefit in these circumstances, and may not be physically possible. Clarify intent to control cooldown rate rather than preventing PTS. * Added Note (4) preceding Step 17, “Previous temperature changes should not be considered

when establishing desired cooldown rate.” * Background Document Step Description, Basis for Step 17, Note 4 provides additional

information. * Background Document Step Description, Basis for Step 17 states that the maximum cooldown

rate is based on ensuring a controlled cooldown.

FORM 2

DISCREPANCY FORM DISCREPANCY SHEET NUMBER 1-23

TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1 CAUTION 2 DISCREPANCY: Change “suction source is lost” to “pump cavitates”. This makes terminology consistent with the rest of the guideline.


Accept suggested change. CAUTION reads, “… loses suction or shows indication of

cavitation,…”


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: ES-1.3 REV.: STEP NUMBER(S): DISCREPANCY: Consider placing transition to SBCRG before step to monitor FRPs in ES-1.3.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Locate the transition step right after SI recirc is established. Locate the FRP monitoring step after this. Basis Document, Introduction discusses this concern.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): DISCREPANCY: Address in Background Document to include on a plant-specific basis some assurance to maintain RHR minimum flow.


Addresses in Background Document, Step Description, Step 1, Basis, Plant-Specific Information,

and Knowledge.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 8 DISCREPANCY: Ensure that the plant-specific means to align CSIP suction to RWST is consistent with the intent of the overall step to have one CSIP from RWST.


Covered by Discrepancy 1-15.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 10 DISCREPANCY: Consider rewording caution before Step 10 to include stopping a CS pump if it indicates cavitation.


Covered by second Caution before Step 1.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 18 DISCREPANCY: Establish a clear priority in Step 18 between prior cooldowns and this cooldown. Some conflict exists if a cooldown is started after previous direction avoided it; do we need to factor in previous cooldown, or start with the current temp?


Covered by Discrepancy 1-22.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 18 DISCREPANCY: In a LB LOCA, would like to be able to bypass actions such as SDM calc when time is critical.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Added new Step 15 to provide bypass of unnecessary actions. All steps bypassed are not applicable for conditions in which RCS is depressurized.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 27 DISCREPANCY: Consider, after establishing normal charging, some way to assess charging/CSIP alignment. Recirc flow for CSIPs back to VCT was “wasting” RWST inventory.


Added instruction to Step 20, “Consult with plant engineering staff to determine desired SI and

CVCS alignment following SI termination.”


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 22 DISCREPANCY: Step 22 must include some consideration that core cooling (RVLIS, CETC’s) is being adequately maintained on normal CHG such that realignment to SI (per curve) is not necessary.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Included a check of SI in service to bypass this step similar to ECA-1.1 (and SI termination sequence). The curve/table is intended to give a flow to reduce to or a check of flow greater than a minimum value.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): DISCREPANCY: When conditions of stable core cooling are reached, consider securing RWST makeup and reestablishing normal VCT makeup alignment.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Once initiated, RWST makeup should continue as a contingency for additional blockage. Switching from RWST makeup to VCT makeup is within determination of optimum alignment (Step 11).


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6 DISCREPANCY: Use Attachment 1 earlier in the procedure.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Earlier use of Attachment 1 would slow down actions to protect pumps and establish some flow. Use of “Attachement 1” is a plant-specific practice. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 1 DISCREPANCY: Do we need explicit instructions to NOT restart pumps.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Issue of pump restart addressed in other discrepancies. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6 DISCREPANCY: b. 2) What is the desired flow? Should we provide a specific flow value? Intent is to obtain minimum flow indicator that indicates time flow (see Attachment 1).

EVALUATOR: Date: 1-29-2004 RESOLUTION: Add “minimum” to flow indication. (Plant-specific may specify value). Background Document Step Description for Step 7, Basis includes reason and additional information for this issue.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: Performed Step 6 with CSIPs running. This re-initiated cavitation and led to no pumps running.


Addressed in Discrepancy 1-10.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 11 DISCREPANCY: Does Step 11 need to be beefed-up. Is there a way to return to earlier steps and re-attempt suction from sump?

EVALUATOR: Date: 1-29-2004 RESOLUTION: Change wording from “Consult” to “Determine”. Add content to fix Steps 1-10 for repeat.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: Is there any way to caption necessary actions for plants/pumps that are vulnerable to air-binding? (including venting of pumps)




TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6 DISCREPANCY: Verbatim compliance does not establish the desired pump alignment/flow conditions.




TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6,7 DISCREPANCY: May be preferable to stop CSIP before attempting establishing low-head injection flow.


Step 3 modified to implement this strategy.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 5 DISCREPANCY: Add Note or background information to allow flow conditions to stabilize after starting/before stopping pumps.


Not necessary to wait for stable conditions. Waiting may unnecessarily delay urgent subsequent

actions. Background Document Step Description for Step 1 – Note 2 addresses this concept.

Identifying Step 1 as a continuous action step provides adequate guidance for delayed changes

in pump operating conditions.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: Need more options – try RWST, try sump again, etc. after Step 10 (Attachment 2).

EVALUATOR: Date: 1-29-2004 RESOLUTION: Use of Attachment 2 and its content are plant-specific. Discrepancy 3-5 addresses the generic issue.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: Indication of cavitation unclear. Stable pressure, less than shut off head with no visible motor current (discharge isolation valves closed).

EVALUATOR: Date: 1-29-2004 RESOLUTION: This is an issue of operator training (and possibly simulator modeling). No change to generic document required. Background Document, Introduction discusses indications of cavitation.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): DISCREPANCY: Need special consideration for plants in which screen is not fully submerged.




TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): DISCREPANCY: For plants that have sump level indication downstream of screen, use behavior (trend) of sump level to determine how much you can increase RHR FCV. Note delayed cavitation indications when sump level decreases after a temporary refill.


Background Document addresses this issue. Delayed cavitation indications add to Operator

Knowledge items in Background Document, Step Description for Step 1.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 6 DISCREPANCY: Consider use of Step 6 with computer indications of RHR flow vice board indicators. Use the behavior of finer indicators to judge success.


Plant-specific item. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1-10 DISCREPANCY: When CA Step 1 is revisited upon indications of RHR pump cavitation and the last running RHR pump is stopped, need to continue to Step 2 to eventually reach Step 8 for alignment of flow from RWST.


Covered previously. See Discrepancy 1-20 and 3-5.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): DISCREPANCY: Consider a Foldout Page item: When both RHR pumps have to be stopped due to cavitation, need to align a HHSI from RWST. Can qualify it for applicability “after have reached a certain point in guideline.”


Not on a generic basis – plant-specific decision to have a Foldout Page.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY X OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 1 DISCREPANCY: There was some concern over the amount of time CSIPs were operating with indications of cavitation before they were stopped.


Covered previously in Discrepancy 1-10.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 5-7 DISCREPANCY: Pumps were started/stopped several cycles – does this place excessive challenge to pump/motor operability?


Background Document justifies Draconian actions for extreme conditions.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 5-8 DISCREPANCY: Should we go directly to RWST for CSIP suction and then attempt re-establishing sump such and receive flow afterwards.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Background Document specifies that sequence of Steps 5 through 8 may vary. On plant-specific basis, RWST alignment may be placed first.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6b DISCREPANCY: Perhaps b. Open isolation valves Check for no cavitation Go to Step __

c. Manually adjust flow


Plant-specific issue to add additional detail. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 6 DISCREPANCY: Format of b RNO is not good for human factors – is there a cleaner way to get to the RNO?

EVALUATOR: Date: 1-29-2004 RESOLUTION: Technically correct. Requires individual plant to modify as required. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 5-8 DISCREPANCY: Procedure does not guide operators through all possible combinations of pump operation. Need to be able to re-try Step 5-8. Possible attachment of possible alignments and flow conditions.


Addressed in Discrepancies 1-20 and 3-5.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 1 DISCREPANCY: Rules of usage: Continuous action Step 1: on second and third iterations, attempted pump restarts in Step 5-8. Is this correct usage? Should it be?


Addressed in Discrepancy 1-20 and 3-5.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 11 DISCREPANCY: When one train (or sump) exhibits “more” blockage than the other for example, one CS pump suction pressure low, not the other, this can be a valuable tool when determining which RHR pump to start later (a “preferred” pump is identified).

EVALUATOR: Date: 1-29-2004 RESOLUTION: TSC is best source for this evaluation following Step 9. Plant engineering staff should determine the preferred alignment based on a variety of considerations. Evaluations of this form are not appropriate for control room operators and should not be detailed in this control room guidelines. No change to generic document required.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS X USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: SBCRG REV.: STEP NUMBER(S): 14,22,30 DISCREPANCY: Consider some note/caution/action to not increase flow (when stable) unless there is a direct reason to do so. Maybe just training or BD preface info.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Addressed by discrepancy 1-5. CAUTIONs preceding Steps 12 and 28 provide guidance on increasing flow.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 10 (also 4) DISCREPANCY: Not clear that pump should be started:


Initial issue was plant-specific. No change to generic document required.

Changes made for other reasons make this discrepancy moot.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 10, 4 DISCREPANCY: Not clear that this is continuous action (plant-specific usage).


Initial issue was plant-specific. No change to generic document required.

Changes made for other reasons make this discrepancy moot.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 14 DISCREPANCY: After discussion with staff, determined no action should be taken. Does this step need more explicit instruction on how/when to increase flow?


Addressed by Discrepancy 3-5.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 11 DISCREPANCY: Caution should allow operators decision to not start spray pump based on expected cavitation (experience that corresponding sup screen was blocked to the extent that only partial RHR flow possible without cavitation).

EVALUATOR: Date: 1-29-2004

RESOLUTION:

Change Step 1 RNO to stop all CS pumps. Delete step 4 In Step 10, run only if suction from sump separate from any RHR pump. Ice condenser and subatmospheric plants need totally different instructions because is providing heat sink. Step 3: stops CS pumps with same suction as RHR pumps before starting RHR pumps.


TYPE OF VERIFICATION DISCREPANCY TYPE OF VALIDATION DISCREPANCY (CHECK APPLICABLE) (CHECK APPLICABLE) WRITTEN CORRECTNESS USABILITY TECHNICAL ACCURACY OPERATIONAL CORRECTNESS ERG DESIGNATOR: REV.: STEP NUMBER(S): 4, 10 DISCREPANCY: Should Note/Step instruct operators to never start spray pump on some suction as RHR pumps.

EVALUATOR: Date: 1-29-2004 RESOLUTION: Revised Step 3 incorporates this concept. Revised Step 9 allows starting spray pumps with suction common to RHR pumps following PES evaluation.

APPENDIX E

SBCRG VERIFICATION AND

VALIDATION DOCUMENTATION FORMS


E-1

FORM 1

VERIFICATION AND VALIDATION DOCUMENTATION SCENARIO NO. (IF APPLICABLE): 1 ERG DESIGNATOR)S): SBCRG GUIDELINE VERIFICATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. WRITTEN CORRECTNESS __________ ______________________ ______________________ 2. TECHNICAL ACCURACY __________ ______________________ ______________________ GUIDELINE VALIDATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. USABILITY X 1-1, 1-3, 1-8, 1-11, 1-12, 1-14, 1-23 2. OPERATIONAL CORRECTNESS X 1-2, 1-4, 1-5, 1-13 ALL ACTIONS REQUIRED IN THE AREA(S) NOTED BELOW HAVE BEEN COMPLETED AND APPROVED. ITEM (CHECK APPROPRIATE) [ ] VERIFICATION [X] VALIDATION [ ] BOTH VERIFICATION AND VALIDATION

__________________________ PROCEDURES WORKING GROUP CHAIRMAN

_________________________ WESTINGHOUSE PLANT OPERATIONS MANAGER


E-2

FORM 1

VERIFICATION AND VALIDATION DOCUMENTATION SCENARIO NO. (IF APPLICABLE): 2 ERG DESIGNATOR)S): SBCRG GUIDELINE VERIFICATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. WRITTEN CORRECTNESS __________ ______________________ ______________________ 2. TECHNICAL ACCURACY __________ ______________________ ______________________ GUIDELINE VALIDATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. USABILITY X 2-1, 2-2, 2-4, 2-6, 2-7 2. OPERATIONAL CORRECTNESS X 2-3, 2-5, 2-8 ALL ACTIONS REQUIRED IN THE AREA(S) NOTED BELOW HAVE BEEN COMPLETED AND APPROVED. ITEM (CHECK APPROPRIATE) [ ] VERIFICATION [X] VALIDATION [ ] BOTH VERIFICATION AND VALIDATION

________________________ PROCEDURES WORKING GROUP CHAIRMAN

_________________________ WESTINGHOUSE PLANT OPERATIONS MANAGER


E-3

FORM 1

VERIFICATION AND VALIDATION DOCUMENTATION SCENARIO NO. (IF APPLICABLE): 3 ERG DESIGNATOR)S): SBCRG GUIDELINE VERIFICATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. WRITTEN CORRECTNESS __________ ______________________ ______________________ 2. TECHNICAL ACCURACY __________ ______________________ ______________________ GUIDELINE VALIDATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. USABILITY X 2. OPERATIONAL CORRECTNESS X ALL ACTIONS REQUIRED IN THE AREA(S) NOTED BELOW HAVE BEEN COMPLETED AND APPROVED. ITEM (CHECK APPROPRIATE) [ ] VERIFICATION [X] VALIDATION [ ] BOTH VERIFICATION AND VALIDATION


____________________________ WESTINGHOUSE PLANT OPERATIONS MANAGER


E-4

FORM 1

VERIFICATION AND VALIDATION DOCUMENTATION SCENARIO NO. (IF APPLICABLE): 4 ERG DESIGNATOR)S): SBCRG GUIDELINE VERIFICATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. WRITTEN CORRECTNESS __________ ______________________ ______________________ 2. TECHNICAL ACCURACY __________ ______________________ ______________________ GUIDELINE VALIDATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. USABILITY X 2. OPERATIONAL CORRECTNESS X ACTIONS REQUIRED IN THE AREA(S) NOTED BELOW HAVE BEEN COMPLETED AND APPROVED. ITEM (CHECK APPROPRIATE) [ ] VERIFICATION [X] VALIDATION [ ] BOTH VERIFICATION AND VALIDATION




E-5

FORM 1

VERIFICATION AND VALIDATION DOCUMENTATION SCENARIO NO. (IF APPLICABLE): 5 ERG DESIGNATOR)S): SBCRG GUIDELINE VERIFICATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. WRITTEN CORRECTNESS __________ ______________________ ______________________ 2. TECHNICAL ACCURACY __________ ______________________ ______________________ GUIDELINE VALIDATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 1. USABILITY X 5-1, 5-2, 5-4 2. OPERATIONAL CORRECTNESS X 5-3, 5-5 ALL ACTIONS REQUIRED IN THE AREA(S) NOTED BELOW HAVE BEEN COMPLETED AND APPROVED. ITEM (CHECK APPROPRIATE) [ ] VERIFICATION [X] VALIDATION [ ] BOTH VERIFICATION AND VALIDATION


___________________________ WESTINGHOUSE PLANT OPERATIONS MANAGER


E-6

FORM 1





E-7

FORM 1

VERIFICATION AND VALIDATION DOCUMENTATION SCENARIO NO. (IF APPLICABLE): 7 ERG DESIGNATOR)S): SBCRG GUIDELINE VERIFICATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 3. WRITTEN CORRECTNESS __________ ______________________ ______________________ 4. TECHNICAL ACCURACY __________ ______________________ ______________________ GUIDELINE VALIDATION OF REVISIONS ACCEPTABLE DISCREPANCY SHEET #(S) 3. USABILITY X 7-1, 7-2 4. OPERATIONAL CORRECTNESS X ALL ACTIONS REQUIRED IN THE AREA(S) NOTED BELOW HAVE BEEN COMPLETED AND APPROVED. ITEM (CHECK APPROPRIATE) [ ] VERIFICATION [X] VALIDATION [ ] BOTH VERIFICATION AND VALIDATION




E-8

FORM 1




• Direct Work Item DW-03-018

• Direct Work Item DW-03-020

• Sump Blockage Control Room Guideline

• Background Information for Westinghouse Owners Group Sump Blockage Guideline

ERG Feedback Direct Work Request Form

Direct Work Number DW-03-018 Pg 1 of 12

ERG Feedback Category 04 Response Letter No. Response Date Affected ERG Version ERG Change - Y ERG-04-007 2/20/2004 HP, LP Human Factors - N Affected Guidelines: E-1, ES-1.3, ECA-1.1

Name: Hank Stroup Address: Harris Nuclear Plant Box 165 City/State/Zip: New Hill NC 27562 Organization: Progress Energy-Harris Nuclear Plant Telephone: 919-362-2637 Submittal Date: 6/9/2003

NOTE: The ERG Maintenance Screening Criteria Checklist (Figure 2) must be submitted with this form. COMMENT OR QUESTION Guidance for diagnosing recirculation sump blockage and potential mitigating actions should be evaluated for incorporation into the ERGs. NRC sponsored technical report LA-UR-02-7562, “The Impact of Recovery From Debris-Induced Loss of ECCS Recirculation of PWR Core Damage Frequency,” has concluded the “potential increase in risk during sump clogging could be reduced by approximately one order of magnitude if PWR licensees have appropriate mitigative measures in place.” The majority of Westinghouse plants have no such guidance; however, it is anticipated many of these plants will find it necessary to develop this guidance as at least an interim measure in response to NRC Bulletin 2003-01, “Potential Impact of Debris Blockage On Emergency Sump Recirculation at Pressurized Water Reactors” PWRs, issued June 9, 2003. The bulletin requires plant provide either (1) evidence the current containment and recirculation sump designs meet regulatory requirements, or (2) a description of interim compensatory actions implemented to reduce the risk of sump blockage. The following recommended mitigating strategies cited in the bulletin and/or WOG letter OG-02-026 are of particular concern:

(1) Delaying switchover to containment recirculation sumps by securing ECCS and Containment Spray pumps that are “not necessary” to provide core or containment cooling. (2) Ensuring alternate sources are available to refill the RWST. (3) Reducing ECCS and Containment Spray flow rates following identification of degraded sump performance after switchover to the recirculation sumps has occurred.

These recommendations are inconsistent with the accident analyses and/or licensing basis of the majority of Westinghouse plants, and/or have previously been rejected in the responses to previous ERG Maintenance Items. Any ERG guidance developed regarding the sump blockage issue must (1) be reconciled with the responses to these previous ERG Maintenance Items, and (2) include some recommendations for individual plants to evaluate the guidance against its licensing basis and accident analyses. Note, that since the response to NRC Bulletin is due within 60 days of issuance, it may be necessary to provide guidance to utilities regarding changes to plant specific EOPs through some mechanism other than an ERG Maintenance Item response.



RESPONSE The Procedures Working Group agrees that guidance for diagnosing recirculation sump blockage and potential mitigating actions should be evaluated for incorporation into the ERGs. To accomplish this, the WOG approved a Project Authorization (PA-SEE-0085) to evaluate potential changes to the ERGs (and Combustion Engineering EPGs) as recommended by NRC Bulletin 2003-01 and the impact of these changes on the Technical Specifications, licensing and design basis, and operational issues associated with the proposed changes. In support of PA-SEE-0085, an Engineering Evaluations and Analysis Report (WCAP-16204) was developed to document the evaluations of potential guideline changes designated as Candidate Operator Actions (COA). The COA were selected from the actions outlined in NRC Bulletin 2003-01, with operations input from the PWG. It is intended that incorporation of any COA into an individual plant’s EOP set must be justified by considering the trade-off between operational, design and housekeeping aspects of NRC Bulletin 2003-01. WCAP-16204 provides guidance in assessing the operational part of this trade-off, including some changes to the ERGs and potential impact on the plant licensing basis, but does not provide plant-specific recommendations. In parallel with development of the COA, the ERG Maintenance Core Group and Westinghouse personnel developed guideline SBCRG, “SUMP BLOCKAGE CONTROL ROOM GUIDELINE”, to provide interim compensatory guidance for responding to sump blockage during recirculation-mode operation of the ECCS and/or containment spray system. This generic guidance is in the form of a “Control Room Guideline” entered from specific ERGs, but separate from the ERG network. The following discussion will identify the specific parts of WCAP-16204 and guideline SBCRG that address the concerns raised in the comment, including associated changes to the ERGs. Each concern will be addressed individually. Concern (1): Delaying switchover to containment recirculation sumps by securing ECCS and Containment Spray pumps that are “not necessary” to provide core or containment cooling. • Candidate Operator Action 1A – Westinghouse Plants (A1a-W), “Operator Action to Secure

One Spray Pump”, evaluates actions to secure one containment spray pump prior to initiating sump recirculation for Westinghouse-designed plants. This action is recommended for implementation at plants with containment fan coolers capable of removing significant heat loads after a LOCA. Three specific reasons are cited for recommending implementation:

1) There is potential for a modest increase in the time to initiate recirculation during small-

break LOCAs (however, this action will have a negligible effect on the plant response to large-break LOCAs).

2) This action has the ability to reduce the flow and potential pressure differential across the recirculation sump screen by the time recirculation begins.

3) Minimal analysis is necessary to incorporate the action into the current EOPs.

Since this action is considered an interim measure, no changes to the generic guideline actions will result from this COA. The following is provided as an example method for incorporating this action into E-1 to assist individual plants in incorporating this COA guidance into their procedures:



Check If Containment Spray Should Be Stopped: a. Spray pumps – ANY RUNNING a. Go to Step (next). b. Determine number of spray pumps required from table:

CONTAINMENT PRESSURE

FAN COOLERS RUNNING IN EMERGENCY

MODE

SPRAY PUMPS

REQUIRED

GREATER THAN (T.03) PSIG ----- 2

BETWEEN (T.04) AND (T.03) AND INCREASING ----- 2

LESS THAN 2 2 BETWEEN (T.04) AND (T.03) AND DECREASING 2 OR MORE 1 LESS THAN (T.04) PSIG ----- 0

c. Spray pumps running – EQUAL TO c. Perform the following: NUMBER REQUIRED

1) Reset containment spray signal.

2) Verify dose analysis assumptions are met as

necessary.

3) Manually operate spray pumps as necessary.

d. Verify containment pressure – d. Return to (substep b).

STABLE OR DECREASING The logic in the example table above is based on the reference plant design, in which design basis containment heat removal capability is provided by operating one spray pump with two fan coolers. Also note that, although the COA specifies a containment temperature criterion (“less than EQ requirement”) for stopping one spray pump, the example table above does not include containment temperature. This is consistent with the ERG design assumption that containment temperature instrumentation is not considered qualified and is not required for design basis accident mitigation. The response of containment pressure is sufficient to confirm that the containment spray pumps have performed their safety function. If the COA guidance is incorporated into E-1 as shown above, the status of the operating spray pump and fan coolers should be monitored, via a continuous action, after a spray pump is stopped. This is necessary to ensure a spray pump is restarted in a timely manner if the



running spray pump or operating fan cooler(s) were to fail. Generic analyses supporting the COA have determined that, if a spray pump is restarted within 10 minutes after failure of the running pump, containment pressure and temperature will remain below assumed limits for the reference plant. Similarly, if the number of operating fan coolers is reduced below two due to subsequent failure, then restarting a spray pump within 10 minutes will maintain containment pressure and temperature below assumed limits. On a plant-specific basis, if it is determined that a spray pump can not be restarted within the time requirements of the associated plant-specific analyses, the COA guidance should not be incorporated into E-1. The operating spray pump and fan coolers must be monitored after a spray pump is manually secured, to ensure the secured spray pump is restarted within the required time if the running spray pump fails. The effectiveness of the plant containment fan coolers will determine the amount of time available to restart the secured spray pump. Note that DW-99-054 revised the Containment status tree F-0.5 to reflect that containment pressure above the High-3/spray actuation setpoint (T.01/T.02) with at least one containment spray pump running constitutes a YELLOW condition (not satisfied) rather than an ORANGE condition (severe challenge) for the containment critical safety function. With this change, FR-Z.1 will only be entered based on operator judgment if a spray pump is stopped with containment pressure above (T.02). If this change has not been implemented, FR-Z.1 would be entered on an ORANGE condition due to containment pressure above (T.01), and FR-Z.1 will direct the operator to start the spray pumps. In this case, the actions of the step in E-1 with the COA guidance incorporated would conflict with the actions directed by FR-Z.1. Individual plants in this situation should either implement the change resulting from DW-99-054 or provide instruction to operate containment spray as directed in the E-1 step rather than as directed by FR-Z.1 To address potential use of the above guidance, the following will be added to the Plant-Specific Information section of the Background Document for E-1 Step 7 (Step 12 LP): o Conditions for stopping one containment spray pump (containment pressure, fan cooler

status) may be included in this step for plants with fan coolers capable of significant post-accident heat removal. Some plants may be able to take credit for use of non-safety grade fan coolers in this capacity.

o If conditions for stopping one containment spray pump are included in this step, plants that credit containment spray in their dose analysis should verify that their dose analysis assumptions are met before stopping one spray pump. Some plants may satisfy these assumptions by verifying SI flow has remained adequate (i.e., no core damage has occurred), while other plants may have additional requirements.

o If conditions for stopping one containment spray pump are included in this step, plants may include this step in other guidelines (for example, ES-1.2) if considered risk beneficial for reducing sump blockage on recirculation.

It should be noted that early reduction of containment spray in E-1, in order to conserve RWST inventory during a severe accident, was rejected by the response to DW-93-021. It was determined that premature termination of containment spray based on RWST level could result in violation of design basis containment pressure transients if a severe accident is not in progress. This concern was discussed in the response as follows:



“Part of the foundation of the ERGs is addressing events that are caused by multiple or subsequent failures that are beyond the plant's design basis while still maintaining the plant's design basis for events that do not contain failures that exceed the design basis assumptions. The Operations Subcommittee believes that it is more important to prevent the violation of the plant's design basis for the most likely events than to take preemptive actions beneficial for a severe accident that could possibly result in the violation of the plant's design basis.”

This discussion reinforces the importance of evaluating the negative aspects of securing containment spray early, including potential violation of the plant licensing basis, before incorporating this guidance into plant-specific EOPs. Each plant should consider the applicable advantages and disadvantages, including whether it is allowable within the plant licensing basis and risk beneficial with respect to potential containment sump blockage.

• Candidate Operator Action 1B (A1b), “Operator Action to Secure Both Spray Pumps”,

evaluates actions to secure all containment spray prior to initiating sump recirculation. This action is recommended for implementation only at plants with containment fan coolers that can remove 100% of the decay heat load when spray is stopped, and spray is not required for iodine removal or pH control. This action has the potential to significantly increase the time to recirculation during small-break LOCAs, however, it will have a negligible effect on time to recirculation during large-break LOCAs.

Since this action is considered an interim measure, no changes to the generic guideline actions will result from this COA. The previous example for incorporating (A1a-W) into E-1 can be used to incorporate (A1b) guidance into plant-specific procedures.

• Early termination of one train of high-head SI or one train of low-head SI was not considered

for Westinghouse plants, beyond the guidance already contained in ES-1.2, “Post LOCA Cooldown and Depressurization”. This guidance will delay depletion of the RWST for small to medium LOCAs by sequentially stopping operating SI pumps based on pre-established criteria that maintains core cooling, thereby delaying switchover to recirculation. For smaller LOCAs, it is possible to cooldown and depressurize the RCS to cold shutdown conditions before the RWST is drained to the switchover level such that recirculation is not required and sump blockage is not an issue.

Concern (2): Ensuring alternate sources are available to refill the RWST. • Candidate Operator Action 5 (A5), “Refill of Refueling Water Storage Tank”, evaluates

actions to prepare to refill the RWST or align an alternate RCS makeup source that bypasses the RWST, in anticipation of possible sump blockage when recirculation occurs. This action is generally recommended for implementation. Note that initiation of RWST refill is not recommended until after switchover to recirculation has occurred.



Injection of greater than one RWST inventory into containment may exceed the containment flooding limit, with the potential for submergence of equipment and instrumentation inside containment that may be required for the recovery. This concern was discussed in the response to DW-93-039, which stated the following:

“Refilling the RWST in ES-1.3 could result in a violation of the plant design basis containment flooding limits and the subsequent loss of equipment and instrumentation used to recover from the accident. Since the intent of the ERGs is to recover from design basis events without violating the plant design basis, adding a RWST refill strategy in ES-1.3 would go against the intent of the ERGs. Therefore, RWST refill will not be included as a recovery strategy in ES-1.3.”

In the ERGs, actions to refill the RWST are included in ECA-1.1 and ECA-3.2 to provide a long-term makeup water supply during certain low-probability, multiple failure events. However, for recovery from a design basis event, refill of the RWST should not be directed in order to maintain compliance with analysis and licensing bases. Note that local actions to prepare for RWST refill (e.g., sampling, aligning valves, removing flanges, connecting hoses, staging temporary pumps, etc.) may be performed during design basis accident recovery. To ensure containment flooding limits are not exceeded, RWST refill should not be initiated while SI or containment spray pumps are still providing injection flow or spray flow from the RWST. However, once injection from the RWST has stopped (i.e., SI pumps and spray pumps are on recirculation) RWST refill may be initiated on a plant-specific basis if applicable conditions are established. For example, some plants may have a margin to the containment flooding limit after completely injecting one RWST inventory; these plants could add makeup to the RWST while monitoring the amount of makeup. Conversely, some plants may have experienced leakage through closed RWST outlet valves; these plants would need some assurance of positive inventory control. Additional measure may be required depending on the source of makeup to the RWST. For example, spent fuel pool level would have to be monitored and maintained above minimum if water is transferred from the pool to the RWST. Additionally, the boron concentration and/or pH of the recirculated sump water could change over the long-term following mixing with the refill water. Conditions governing RWST refill could be placed in the plant-specific TSC guidance document, enabling the plant engineering staff to assist the operators in this action. Note that, if RWST outlet isolation has occurred and can be assured for the long-term, there should be no restrictions on initiating refill and plant engineering staff evaluation would not be required. Given the above considerations, plants may add guidance for initiating RWST refill after recirculation alignment has been established for the SI and containment spray systems. Since this action is considered an interim measure, no changes to the generic guideline actions will result from this COA. The following is provided as an example method for incorporating this action into ES-1.3 (after recirculation switchover is completed) to assist individual plants in incorporating this COA guidance into their procedures: Determine If RWST Refill Should Be Initiated:

a. Consult plant engineering staff



Concern (3): Reducing ECCS and Containment Spray flow rates following identification of degraded sump performance after switchover to the recirculation sumps has occurred. • Candidate Operator Action 9 – Westinghouse Plants (A9-W), “Develop Contingency Actions

in Response to: Containment Sump Blockage, Loss of Suction, and Cavitation”, evaluates the feasibility and appropriateness of numerous actions in response to sump blockage, loss of ECCS pump suction and cavitation. In general, the following actions were determined to be advantageous for response to sump blockage:

- Stop Pumps Experiencing Loss of Suction to Prevent Pump Damage - Reduce Recirculation Flow to the Minimum Required to Support Design Basis or

Critical Safety Functions - Verify Containment Cooling Unit Operation to Minimize Cooling Demand for

Containment Spray Flow - Establish Alternate Water Sources to Inject into the Reactor Core and Spray into the

Containment - Optimize Use of Available Sources of Flow for Injection into the Reactor Core and

Spray into the Containment - Cooldown and Depressurize the RCS Using the Secondary System to Reduce Required

Injection Flow to the RCS and Allow Placing the RHR System in Service

These actions have been included in the generic guideline SBCRG, “SUMP BLOCKAGE CONTROL ROOM GUIDELINE”. The SBCRG provides interim compensatory guidance for responding to sump blockage during the recirculation mode operation of the ECCS and/or containment spray system. The guidance is considered interim since future actions (analysis and/or plant modifications) must eventually resolve the associated Generic Safety Issue, GSI-191. Individual plants that achieve long-term resolution of GSI-191 will no longer require interim compensatory actions. The SBCRG is separate from the ERG network, as sump blockage renders the guidance in the ERGs ineffective. Individual plants may implement the guidance of the SBCRG in several ways, including:

- Issue this guidance as a unique document, similar to the Severe Accident Management

Guidelines, or - Issue this guidance as a new procedure, either as a part of the EOPs or in a different set

of procedures, or - Incorporate selected parts of the guidance into existing procedures (such as ECA-1.1,

LOSS OF EMERGENCY COOLANT RECIRCULATION), or - Use some other plant-specific implementation strategy.



It is acknowledged that some plants have already implemented procedure changes to address the interim compensatory measures of NRC Bulletin 2003-01. Issuance of the SBCRG should not require those plants to change the format or content of compensatory guidance that has already been implemented.

• Candidate Operator Action 8 – Westinghouse Plants (A8-W), “Provide Guidance on

Symptoms and Identification of Containment Sump Blockage”, evaluates the use of all available instrumentation to identify symptoms of containment sump blockage or degraded ECCS pump performance. This guidance is recommended for implementation at all plants as a transition to the plant-specific sump blockage recovery actions. On a generic basis, the SBCRG is entered upon indications of loss of pump suction caused by recirculation sump blockage that prevents establishing or maintaining at least one train of ECCS flow in the recirculation mode. For most plants, indication of loss of pump suction is limited to symptoms of pump cavitation. To provide an interface with the ERG network, the following guidelines will include explicit transitions to the SBCRG:

- ES-1.3, TRANSFER TO COLD LEG RECIRCULATION, Step 5, when sump blockage

prevents establishing or maintaining at least one train of SI recirculation flow, and - ECA-1.1, TRANSFER TO COLD LEG RECIRCULATION, Step 1, when sump

blockage prevents maintaining at least one train of SI recirculation flow.

The plant-specific implementation of these transitions to SBCRG should observe the following criteria: - The transition step from ES-1.3 should immediately follow the first step that verifies or

establishes flow from the recirculation sump. Sump blockage may occur soon after establishing flow from the sump. If this occurs, operators must transition to SBCRG as soon as possible.

- The transition steps from ES-1.3 and ECA-1.1 are continuous action steps that continue

to apply to all subsequent guidelines entered after the applicable step. Sump blockage may build up gradually over an extended time. If worsening sump blockage causes delayed loss of recirculation suction, operators must be able to transition to SBCRG at any time.

Based on the above information, the following continuous action step will be added as Step 5 (HP and LP) of ES-1.3:



5 Verify ECCS Pumps Not Affected IF both trains are affected such that

By Sump Blockage: at least one train of SI recirculation flow can not be established or

[Enter plant-specific means] maintained, THEN go to SBCRG, SUMP BLOCKAGE CONTROL

ROOM GUIDELINE, Step 1.

IF only one train is affected, THEN take actions to protect the affected train:


Additionally, the following continuous action step will be added as Step 1 (HP and LP) of ECA-1.1: 1 Verify ECCS Pumps Not Affected IF both trains are affected such that

By Sump Blockage: at least one train of SI recirculation flow can not be maintained, THEN

[Enter plant-specific means] go to SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE,

Step 1. The following will be added to the Step Description Table of ES-1.3 (HP and LP) to support the new Step 5 (HP and LP) of ES-1.3: STEP: Verify ECCS Pumps Not Affected By Sump Blockage: PURPOSE: To ensure that ECCS pumps operating on recirculation are not exhibiting

symptoms of distress BASIS: Following a high energy line break inside containment, analyses have determined that debris transported to the recirculation sump may collect on the sump screen such that flow through the sump may be inadequate to support operation of ECCS pumps on recirculation. Most plants do not have instrumentation capable of directly detecting sump blockage (such as screen differential pressure) therefore symptoms of pump distress resulting from the sump blockage will be used to determine if blockage exists. Indications of pump cavitation or loss of suction caused by sump blockage normally include erratic or abnormally reduced pump motor current, discharge pressure or flow, or abnormally high pump vibration. Conversely, these indications would be stable at normal values if no sump blockage is evident.



If indications of ECCS pump cavitation are observed, it is expected that operators will take action to protect the pumps from damage. It is possible that only one train of ECCS will be affected by sump blockage, such that the other train is capable of providing recirculation flow. In this case the operator should continue with the procedure in effect while taking actions to protect the affected pumps. SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE, provides interim compensatory guidance for responding to sump blockage during recirculation. This guidance is separate from the ERG network, and is applicable to conditions in which sump blockage renders the guidance in the ERGs ineffective. It is important that SBCRG only be entered when both trains of ECCS are so degraded that recirculation flow can not be established or maintained. ACTIONS: o Monitor ECCS pump operating conditions o Determine if ECCS pump(s) are operating normally o Determine if SI recirculation flow can be established or maintained o Take actions to protect affected ECCS pumps o Transfer to SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE INSTRUMENTATION: o SI pump flow indication o SI pump discharge pressure indication o SI pump motor current indication CONTROL/EQUIPMENT: N/A KNOWLEDGE: o This step is a continuous action step o Symptoms of pump cavitation PLANT-SPECIFIC INFORMATION: o If additional indications of sump screen blockage such as screen differential pressure,

internal sump water level, pump suction pressure, and computed low NPSH alarms are available, they should be included in this step.



The following will be added to the Step Description Table of ECA-1.1 (HP and LP) to support the new Step 1 (HP and LP) of ECA-1.1: STEP: Verify ECCS Pumps Not Affected By Sump Blockage: PURPOSE: To ensure that ECCS pumps operating on recirculation are not exhibiting

symptoms of distress

BASIS: Following a high energy line break inside containment, analyses have determined that debris transported to the recirculation sump may collect on the sump screen such that flow through the sump may be inadequate to support operation of ECCS pumps on recirculation. Most plants do not have instrumentation capable of directly detecting sump blockage (such as screen differential pressure) therefore symptoms of pump distress resulting from the sump blockage will be used to determine if blockage exists. Indications of pump cavitation or loss of suction caused by sump blockage normally include erratic or abnormally reduced pump motor current, discharge pressure or flow, or abnormally high pump vibration. Conversely, these indications would be stable at normal values if no sump blockage is evident. This step is included here to ensure that operators do not remain in ECA-1.1 if sump blockage is the cause of the recirculation loss, as ECA-1.1 does not provide appropriate guidance for recovery from that condition. ECA-1.1 may have been entered before symptoms resulting from sump blockage are evident, or the loss of recirculation may have been attributed to pump or valve malfunction rather than sump blockage. This step provides a mechanism to either confirm that the operator is in the proper guideline or to direct the operator to the guideline that should be in effect. SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE, provides interim compensatory guidance for responding to sump blockage during recirculation. This guidance is separate from the ERG network, and is applicable to conditions in which sump blockage renders the guidance in the ERGs ineffective. It is important that SBCRG only be entered when both trains of ECCS are so degraded that recirculation flow can not be established or maintained. ACTIONS: o Monitor ECCS pump operating conditions o Determine if ECCS pump(s) are operating normally o Determine if SI recirculation flow can be maintained o Transfer to SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE INSTRUMENTATION: o SI pump flow indication o SI pump discharge pressure indication o SI pump motor current indication



CONTROL/EQUIPMENT: N/A KNOWLEDGE: o This step is a continuous action step o Symptoms of pump cavitation PLANT-SPECIFIC INFORMATION: o If additional indications of sump screen blockage such as screen differential pressure,

internal sump water level, pump suction pressure, and computed low NPSH alarms are available, they should be included in this step.

These changes will be included with the documentation for SBCRG, but will not be incorporated into Revision 2 of the ERGs. Subsequent changes to this material will be evaluated for incorporation in future ERG revisions.



ERG Feedback Category 04 Response Letter No. Response Date Affected ERG Version ERG Change - N ERG-04-008 2/20/2004 Human Factors - N Affected Guidelines:

Name: Bob Bryan Address: 1101 Market Street City/State/Zip: Chattanooga TN 27402 Organization: Tennessee Valley Authority Telephone: 423-751-8201 Submittal Date: 8/14/2003

NOTE: The ERG Maintenance Screening Criteria Checklist (Figure 2) must be submitted with this form. COMMENT OR QUESTION This applies to the Ice Condenser Plants. For small RCS breaks, we want to be able to put both containment spray pumps in pull to lock. The size break we want to use is 500 gpm or less. The reason that this should be done is that while there is ice in the ice condenser, the spray pumps do not provide any pressure suppression. For these small breaks, it will be many hours before the ice is melted. More importantly, if the sprays start, the plant will transition from injection to sump recirculation in less than one hour. Without sprays, switchover to sump recirculation will not take place until about 9 hours for a 500 gpm break or 18 hours for a 250 gpm break. Since the transition to sump recirculation dominates the core damage frequency risk for small breaks, this is a very positive step from a risk perspective. Further, for the sump issue, allowing the sprays to come on changes the flow through the sump from 500 gpm to a value closer to 10,000 gpm. A 10,000 gpm-flowrate will transmit much more material a much longer distance. So, preventing the sprays from running will substantially reduce the likelihood of sump blockage. RESPONSE The Procedures Working Group agrees that actions to prevent or delay automatic actuation of the containment spray system following smaller break LOCAs may reduce the likelihood of sump blockage and thus be beneficial for ice condenser plants. An analysis of these actions is provided in WCAP-16204. However, since the ERG reference plant is based on the large, dry containment design, no changes to the ERGs will result from this evaluation. The PWG provides the following discussion: The WOG approved a Project Authorization (PA-SEE-0085) to evaluate potential changes to the ERGs (and Combustion Engineering EPGs) as required by NRC Bulletin 2003-01 and the impact of these changes on the Technical Specifications, licensing and design basis, and operational issues associated with the proposed changes. In support of PA-SEE-0085, an Engineering Evaluations and Analysis Report (WCAP-16204) was developed to document the evaluations of potential guideline changes designated as Candidate Operator Actions (COA). The COA were selected from the actions outlined in NRC Bulletin 2003-01, with operations input from the PWG. It is intended that incorporation of any COA into an individual plant’s EOP set must be justified by considering the trade-off between operational, design and housekeeping aspects of



NRC Bulletin 2003-01. WCAP-16204 provides guidance in assessing the operational part of this trade-off, but does not provide plant-specific recommendations. Candidate Operator Action 11 (A11), “Prevent or Delay Containment Spray for Small Break LOCAs (< 1.0 Inch Diameter) in Ice Condenser Plants”, evaluates the feasibility and appropriateness of actions to prevent or delay automatic actuation of the containment spray system for ice condenser plants. This evaluation concluded that licensees may determine, based on the potential for debris related concerns, as well as enhancing plant response to smaller break LOCAs, that it is advisable to implement logic changes to prevent automatic initiation of containment spray until ice melt. Note that actions blocking the automatic actuation of safeguards equipment or modification of the spray actuation setpoint will require a revision to licensing documentation and a 10CFR50.59 evaluation with accompanying re-analysis of containment transients using the new actuation setpoint. Based on the above information, no modifications to the ERGs are required.

Number SBCRG W-PLANTS


Rev./Date HP/LP Rev. 0 03/23/2004

SBCRG – W-PLANTS 1 of 21

A. PURPOSE This guideline provides actions to respond to a recirculation sump blockage condition that prevents establishing or maintaining at least one train of ECCS flow in the recirculation mode.

B. SYMPTOMS AND ENTRY CONDITIONS This guideline is entered from: 1) ES-1.3, TRANSFER TO COLD LEG RECIRCULATION, Step 5 when indications of pump

cavitation caused by sump blockage prevent establishing or maintaining at least one train of ECCS flow in the recirculation mode.

2) ECA-1.1, LOSS OF EMERGENCY COOLANT RECIRCULATION, Step 1 when indications

of pump cavitation caused by sump blockage prevent establishing or maintaining at least one train of ECCS flow in the recirculation mode.






CAUTION • Any pump receiving suction from a low-head SI pump should be stopped before stopping the low-head SI pump.

• If any charging/SI pump, high-head SI pump or spray pump loses suction or shows indication of cavitation, the pump should be stopped.

NOTE • CSF Status Trees should be monitored for information only.

FRGs should not be implemented. • Indications of cavitation should be monitored following any

change of recirculation flow. *1 Monitor Low-Head SI Pump Suction

Conditions – NO INDICATION OF CAVITATION [Enter plant-specific means]

Perform the following: 1) Stop any charging/SI pump(s) and

high-head SI pump(s) taking suction from affected low-head SI pump(s)

2) Stop any containment spray pump(s) taking suction from sump.

3) IF indications of cavitation continue, THEN close RHR flow control valve(s).

4) IF indications of cavitation continue, THEN close associated RHR injection isolation valve(s).

5) IF indications of cavitation continue, THEN stop affected low-head SI pump(s).

2 Verify Containment Fan Coolers - RUNNING IN EMERGENCY MODE

Manually start fan coolers in emergency mode.

3 Stop Containment Spray Pumps


*4 Monitor RWST Level – GREATER THAN (U.03)

Stop all pumps taking suction from RWST.






5 Try To Establish SI Recirculation Suction:

a. Any low-head SI pump – RUNNING WITH SUCTION FROM SUMP


1) Close RHR injection isolation valve(s).

2) Start one low-head SI pump.

3) IF indications of cavitation occur, THEN stop the running pump AND start the other low-head SI pump.

4) IF no low-head SI pump will run without indications of cavitation, THEN stop any running low-head SI pump AND go to Step 8.

b. Close RHR injection isolation valves

c. Low-head SI pumps – ONLY ONE RUNNING WITH SUCTION FROM SUMP

c. Start or stop low-head SI pumps to obtain one pump running with suction from sump.

6 Try To Establish High-Head SI In

Recirculation Mode:

a. High-head SI pump and charging/SI pump - SUCTIONS ALIGNED TO RUNNING LOW-HEAD SI PUMP

a. Align high-head SI pump and charging/SI pump suctions to running low-head SI pump. [enter plant-specific means]

b. High-head SI pumps and charging/SI pumps – ONLY ONE RUNNING

b. Start or stop high-head SI pumps and charging/SI pumps to obtain one high-head SI pump or charging/SI pump running in recirculation alignment.

c. High-head SI pump or charging/SI pump – RUNNING IN RECIRCULATION ALIGNMENT

c. Go to Step 7.

d. Go to Step 9






7 Try To Establish Low-Head SI Recirculation Flow:

a. RCS pressure – LESS THAN (B.07) PSIG [(B.08) PSIG FOR ADVERSE CONTAINMENT]

a. Go to Step 8.


1) Close RHR flow control valves

2) Open low-head SI injection isolation valves

3) Manually adjust flow control valves to establish minimum indication of low-head SI injection flow without cavitation


1) Stop the running low-head SI pump.

2) Start the other low-head SI pump.

3) Manually adjust flow control valve to establish minimum indication of low-head SI injection flow without cavitation.

4) IF indications of cavitation occur with flow control valve closed, THEN perform the following:

a) Close the low-head SI injection isolation valves.

b) Stop any running low-head SI pump.

c) Go to Step 8.


c. Go to Step 9






8 Try To Establish High-Head SI With Suction From RWST:

a. Check RWST level – GREATER THAN (U.03)

a. Go to Step 9.

b. Any high-head SI pump or charging/SI pump suction – ALIGNED TO RWST

b. Align high-head SI pump and charging/SI pump suctions to RWST.

c. Start or stop high-head SI pumps and charging/SI pumps to obtain one running with suction from RWST

9 Consult Plant Engineering Staff To Determine Optimum SI And Spray Alignment

10 Verify No Backflow From RWST To Sump: a. Sump recirculation valves – ANY

OPEN a. IF both sump recirculation valves

closed, THEN go to Step 11. b. Valve from RWST to low-head SI

pump in same train – CLOSED b. Manually close valve(s).

11 Add Makeup To RWST As Necessary: [Enter plant-specific means]






CAUTION SI recirculation flow should not be increased to a condition that causes indication of SI pump cavitation.

NOTE Before starting any pump with suction aligned to low-head SI

pumps, adequate suction path should be ensured.






a. Try to increase RVLIS indication using any of the following:

• Increase SI flow.

• Add makeup to RCS from alternate source.



b. Try to maintain TCs stable or decreasing using any of the following:

• Increase SI flow.

• Dump steam from intact SGs.



*13 Operate ECCS To Maintain RCS Makeup Flow Without Pump Cavitation: • Start or stop pumps as required • Align flowpaths as required • Throttle flow as required [Enter plant-specific means]






*14 Monitor For RCS Makeup Capability: • Charging/SI pump flow indicators –

FLOW INDICATED - OR –

• High-head SI pump flow indicators – FLOW INDICATED - OR –

• Low-head SI pump flow indicators – FLOW INDICATED

Try to restore RCS makeup capability. IF RCS makeup capability can NOT be restored, THEN go to Step 34.

15 Check RCS pressure: GREATER THAN (B.07) PSIG [(B.08) PSIG FOR ADVERSE CONTAINMENT]

Go to Step 39.

CAUTION Alternate water sources for AFW pumps will be necessary if CST level decreases to less than (U.01).

*16 Check Intact SG Levels: a. Narrow range level – GREATER THAN

(M.02)% [(M.03)% FOR ADVERSE CONTAINMENT]

a. Maintain total feed flow greater than (S.02) gpm until narrow range level greater than (M.02)% [(M.03)% for adverse containment] in at least one SG.

b. Control feed flow to maintain narrow range level between (M.02)% [(M.03)% for adverse containment] and 50%

b. IF narrow range level in any SG continues to increase, THEN stop feed flow to that SG.






NOTE • Shutdown margin should be monitored during RCS cooldown.

• Low steamline pressure SI signal should be blocked when PRZR pressure decreases to less than (A.05) psig.

• After the low steamline pressure SI signal is blocked, main steamline isolation will occur if the high steam pressure rate setpoint is exceeded.

• Previous temperature changes should not be considered when establishing desired cooldown rate.

17 Initiate RCS Cooldown To Cold Shutdown:


b. Dump steam to condenser from intact SG(s)

b. Manually or locally dump steam from intact SG(s):

• Use PORV.

-OR-


IF no intact SG available, THEN use faulted SG.






CAUTION If RCP seal cooling had previously been lost, the affected RCP(s) should not be started prior to a status evaluation.

NOTE RCPs should be run in order of priority to provide normal PRZR

spray.

18 Check If An RCP Should Be Started:

a. All RCPs - STOPPED a. Stop RCP(s) NOT required for normal PRZR spray. Go to Step 19.


b. Go to Step 19.

c. Try to start an RCP to provide normal PRZR spray:

1) Establish conditions for starting an RCP:


2) Start RCP in loop with surge line

c. IF RCP in loop with surge line can NOT be started, THEN try to start other RCP(s) as necessary to provide normal spray.

19 Check If SI Is In Service: • High-head SI pumps – ANY RUNNING

- OR – • BIT – NOT ISOLATED

- OR – • Low-head SI pumps – ANY RUNNING IN

SI MODE

Go to Step 28.






*20 Check If SI Can Be Terminated:



-OR-


a. Go to Step 28.



1) Determine minimum SI flow required to remove decay heat from Figure SBCRG-1.

2) Try to establish minimum SI flow without causing indications of pump cavitation.

3) Go to Step 28.

c. Charging/SI pumps – AT LEAST ONE RUNNING


1) Consult with plant engineering staff to determine desired SI termination sequence.

2) Go to Step 28.

d. Consult with plant engineering staff to determine desired SI and CVCS alignment following SI termination

21 Reset Containment Isolation Phase A And Phase B

22 Establish Instrument Air To Containment

Start one air compressor and establish instrument air to containment.

23 Stop SI Pumps And Place In Standby:

• High-head SI pumps

• All but one charging/SI pump






24 Isolate BIT:

a. Check charging/SI pump – SUCTION ALIGNED TO RWST

a. IF aligned to the discharge of the low-head SI pumps in the SI recirculation mode, THEN perform the following:

1) Close charging line hand control valve.

2) Open charging line isolation valves.

3) Open charging flow control valve (S.0.6)%.

4) Close BIT inlet isolation valves.

5) Close BIT outlet isolation valves.

6) Establish and maintain (S.01) gpm charging flow using charging flow control valve and charging line hand control valve.

7) Go to Step 26.

b. Check charging/SI pump miniflow isolation valves - OPEN

b. Manually open valves.

c. Close BIT inlet isolation valves

d. Close BIT outlet isolation valves

25 Establish Charging Flow:

a. Close charging line hand control valve

b. Open charging line isolation valves

c. Establish desired charging flow using charging flow control valve and charging line hand control valve






26 Check If Charging/SI Pump Should Be Realigned To RWST:

a. RWST level – GREATER THAN (U.03) a. Go to Step 28.


b. Go to Step 28.

c. Consult plant engineering staff to determine if charging/SI pump suction should be realigned to RWST

27 Check If Running Low-head SI Pump Should Be Stopped

a. Charging/SI pumps – NO RUNNING PUMP SUCTION ALIGNED TO LOW-HEAD SI PUMP

a. Go to Step 28.

b. Stop running low-head SI pump and place in standby






CAUTION SI recirculation flow should not be increased to a condition that causes indication of SI pump cavitation.

NOTE Before starting any pump with suction aligned to low-head SI

pumps, adequate suction path should be ensured.






a. Try to increase RVLIS indication using any of the following:

• Increase ECCS flow.




b. Try to maintain TCs stable or decreasing using any of the following:

• Increase ECCS flow.

• Dump steam from intact SGs.








NOTE The upper head region may void during RCS depressurization if RCPs are not running. This will result in a rapidly increasing PRZR level.


a. RCS subcooling based on core exit TCs - GREATER THAN (R.08)°F [(R.09)°F FOR ADVERSE CONTAINMENT]

a. Go to Step 30.

b. Use normal PRZR spray b. Use one PRZR PORV. IF RCS can NOT be depressurized using any PRZR PORV, THEN use auxiliary spray.

c. Depressurize RCS until either of the following conditions satisfied:

• RCS subcooling based on core exit TCs - BETWEEN (R.01)°F [(R.02)°F FOR ADVERSE CONTAINMENT] AND (R.08)°F [(R.09)°F FOR ADVERSE CONTAINMENT]

-OR-

• PRZR level - GREATER THAN (D.08)% [(D.09)% FOR ADVERSE CONTAINMENT]

c. IF RCS subcooling less than (R.01)°F [(R.02)°F for adverse containment], THEN increase RCS makeup flow as necessary to restore subcooling.

d. Stop RCS depressurization










a. Go to Step 31.




a. Continue with Step 32. WHEN at least two RCS hot leg temperatures less than (F.05)°F, THEN do Steps 31b and c.








-OR-









33 Check RCS Temperature - GREATER THAN 200°F

Go to Step 41.

34 Try To Add Makeup To RCS From Alternate Source:



a. RVLIS indication:

• Full range – GREATER THAN (K.02) IF NO RCP RUNNING

- OR –

• Dynamic head range – GREATER THAN (L.08) IF ONE RCP RUNNING

a. Go to Step 36.

b. Core exit TCs – STABLE OR DECREASING

b. Go to Step 36.


36 Check If All Intact SGs Should Be Depressurized To (O.06) PSIG:

a. Check SG pressures - GREATER THAN (O.06) PSIG

a. Go to Step 37.

b. Dump steam to condenser at maximum rate

b. Manually or locally dump steam at maximum rate from intact SG(s):

• Use PORV.

-OR-


c. Check SG pressures – LESS THAN (O.06) PSIG

c. Return to Step 36b.

d. Stop SG depressurization







a. Dump steam to condenser as necessary to maintain appropriate RVLIS indication:

• Full range at (K.02) - IF NO RCP RUNNING

-OR-

• Dynamic head range at (L.08) - IF ONE RCP RUNNING

a. Manually or locally dump steam from intact SG(s) as necessary to maintain appropriate RVLIS indication:

• Use PORV.

-OR-


b. Check SG pressures – LESS THAN (O.07) PSIG

b. Return to Step 37a.

c. Stop SG depressurization



a. Continue with Step 39. WHEN at least two RCS hot leg temperatures less than (F.05)°F, THEN do Steps 38b and c.













-OR-




40 Depressurize All Intact SGs To Atmospheric Pressure:

a. Maintain cooldown rate in RCS cold legs – LESS THAN 100°F/HR

b. Dump steam to condenser b. Manually or locally dump steam from intact SG(s):

• Use PORV.

-OR-


41 Check Core Exit TCs – LESS THAN 1200oF IF core exit temperatures greater than 1200oF and increasing, THEN go to SACRG-1, SEVERE ACCIDENT CONTROL ROOM GUIDELINE INITIAL RESPONSE, Step 1.












*43 Maintain RCS Heat Removal:

a. Use RHR System if in service

b. Dump steam to condenser from intact SGs

b. Manually or locally dump steam from intact SGs:

• Use PORV.

-OR-


IF no intact SG available and RHR system NOT in service, THEN use faulted SG.


a. Obtain a hydrogen concentration measurement:


b. Hydrogen concentration - LESS THAN (T.05)% IN DRY AIR

b. Consult plant engineering staff for additional recovery actions. Go to Step 45.

c. Hydrogen concentration - LESS THAN 0.5% IN DRY AIR

c. Turn on hydrogen recombiner system.






45 Consult Plant Engineering Staff

– END –





10 100 1000 10000

EXAMPLE ONLY

Flow Rate (GPM)

Time (Minutes)

0

100

200

300

400

500

600

FIGURE SBCRG-1. MINIMUM SI FLOW RATE VERSUS TIME AFTER TRIP

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BACKGROUND INFORMATION FOR

WESTINGHOUSE OWNERS GROUP SUMP BLOCKAGE GUIDELINE

SBCRG (W-PLANTS) SUMP BLOCKAGE CONTROL ROOM GUIDELINE (W-PLANTS)

HP/LP Rev. 0 March 23, 2004

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SBCRG Background (W-PLANTS) i HP/LP Rev. 0

TABLE OF CONTENTS SECTION PAGE 1. INTRODUCTION 1 2. DESCRIPTION 5 3. RECOVERY/RESTORATION TECHNIQUE 8

3.1 High Level Action Summary 8 3.2 Key Utility Decision Points 10

4. DETAILED DESCRIPTION OF GUIDELINE 12

4.1 Detailed Description of Steps, Notes, and Cautions 12 4.2 Step Sequence Requirements 113

5. FREQUENT QUESTIONS 116 6. REFERENCES 119 FIGURES 1. Cold Leg Recirculation Phase 7 2. Decay Heat Flow Rate Per MWt Versus Time After Trip 66

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SBCRG Background (W-PLANTS) 1 HP/LP Rev. 0

1. INTRODUCTION Guideline SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE, provides interim compensatory guidance for responding to sump blockage during recirculation-mode operation of the Emergency Core Cooling System (ECCS) and/or Containment Spray (CS) System. The SBCRG is applicable to all situations in which sump blockage makes the guidance in the Emergency Response Guidelines (ERGs) ineffective. Operators enter this guideline based upon indications of loss of pump suction caused by recirculation sump blockage that prevents establishing or maintaining at least one train of ECCS flow in the recirculation mode. For most plants, indication of loss of pump suction is limited to symptoms of pump cavitation. The SBCRG guidance is a part of the interim response to NRC Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors. The guidance is interim in nature because future actions (analysis and/or plant modifications) must resolve the associated Generic Safety Issue (GSI) 191. Individual facilities that have achieved long-term resolution of GSI 191 no longer require interim compensatory actions. This generic guidance for responding to sump blockage is in the form of a “Control Room Guideline” separate from the Emergency Response Guideline network. Issuance of the SBCRG does not change the ERG network nor does it create a requirement for any plant to incorporate the content of this guideline into the approved plant procedures. The format and style of the SBCRG is consistent with the ERG Writer’s Guide. The SBCRG borrows elements and information from the ERGs, including the Footnotes (and, by inference, the Footnote Basis Document), the Plant Engineering Staff Evaluation document (part of the Executive Volume, Generic Issues section) and various ERGs and associated Background Documents. This format provides individual plants the greatest flexibility in implementing the guidance. Individual plants may select the implementation strategy best suited to their needs: • Issue this guidance as a unique document, similar to the Severe Accident Management

Guidelines, or • Issue this guidance as a new procedure (either as a part of the Emergency Operating

Procedures or in a different set of procedures), or • Incorporate selected parts of the guidance into existing procedures (such as ECA-1.1, LOSS

OF EMERGENCY COOLANT RECIRCULATION), or • Use some other plant-specific implementation strategy. The following considerations led to adopting this non-prescriptive approach to implementation: • The requirement for this guidance, as described in NRC Bulletin 2003-01 is part of the

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interim compensatory measures (Option 2). Upon resolution of GSI 191, the requirement for this guidance no longer applies. Maintaining this guidance outside the Emergency Response Guideline (ERG) network facilitates more rapid implementation (and subsequent deletion) of this guidance.

• Any individual facility that has completed the Option 1 requirements of NRC Bulletin 2003-01 no longer has a requirement to maintain interim compensatory measures, including this guidance.

• Some facilities have already implemented procedure changes on plant-specific basis. Issuance of this guideline should not require these facilities to change the format or content of compensatory guidance that has already been implemented.

• The background of the ERGs includes detailed analysis that demonstrates the effectiveness of action setpoints and recovery strategies in maintaining Critical Safety Functions. The uncertain nature of recirculation sump blockage prevents developing equivalent levels of assurance for the success of strategies in response to this challenge.

The following guidelines include explicit transitions to guideline SBCRG:

1. ES-1.3, TRANSFER TO COLD LEG RECIRCULATION, Step 5, when sump blockage prevents establishing or maintaining at least one train of SI recirculation flow,

2. ECA-1.1, LOSS OF EMERGENCY COOLANT RECIRCULATION, Step 1, when sump blockage prevents maintaining at least one train of SI recirculation flow.

The plant-specific implementation of these transitions to SBCRG should observe the following criteria:

• The transition step from ES-1.3 should immediately follow the first step that verifies or establishes flow from the recirculation sump. Sump blockage may occur soon after establishing flow from the sump. If this occurs, operators must transition to SBCRG as soon as possible.

• The transition steps from ES-1.3 and ECA-1.1 are continuous action steps that continue to apply to all subsequent guidelines entered after the applicable step. Sump blockage may build up gradually over an extended time. If worsening sump blockage causes delayed loss of recirculation suction, operators must be able to transition to SBCRG at any time.

Individual plants must determine the most effective indications of sump blockage available to the operators. Most plants do not provide control board display of parameters directly associated with sump blockage or loss of pump suction. Examples of parameters directly associated with sump blockage include:

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• For plants in which the sump screen is expected to be completely submerged during recirculation conditions; differential pressure across the sump screen

• For plants in which the sump screen is expected to be partially above the water level during recirculation conditions; water level inside the sump screen

• SI pump and spray pump suction pressure Plants that do provide indication of parameters directly associated with sump blockage should specify use of these parameters in determining whether excessive sump blockage exists. Whenever possible, plant-specific action setpoints should be determined for these parameters. This may not be possible because the values of the parameters depend on other parameters, such as total recirculation flow, as well as the degree of sump blockage. For long-term monitoring, tables or graphs of acceptable parameter values ve rsus recirculation flow may be useful. For plants in which the sump screen is expected to be partially uncovered during recirculation and internal sump level is available, an action setpoint should be selected that precludes air entrainment into the recirculation piping. Since the development of such information is highly plant-specific, this document provides no specific calculation methods. Plants that do not provide control board display of parameters directly associated with sump blockage must use parameters that indirectly indicate loss of pump suction. Typical parameters associated with loss of pump suction include pump discharge pressure, system flow and motor current. For these parameters, no explicit action setpoints exist that provide definitive diagnosis of sump blockage. Proper entry into the SBCRG guideline depends on operator interpretation of multiple parameters. Existing licensed operator training standards require knowledge of the symptoms and response to generic loss of suction for centrifugal pumps. For example, a typical set of conditions indicating that excessive sump blockage does NOT exist might be: • SI flow – STABLE AND CONSISTENT WITH RCS PRESSURE • SI pump discharge pressure – STABLE AND CONSISTENT WITH SI FLOW • SI pump motor cur rent – STABLE AND CONSISTENT WITH SI FLOW For typical plants, none of the instrumentation described above meet the requirements of Regulatory Guide 1.97. The NRC Staff Responses to Industry Pre-Meeting Questions and Comments on Bulletin 2003-01 Provided in Support of June 30, 2003 NRC Public Meeting provides the following NRC staff response to item #15:

“As the interim compensatory measures requested in the bulletin are intended as risk reduction measures, the staff finds that non-Regulatory Guide 1.97 instrumentation may be used for this purpose.”

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Two transitions from the SUMP BLOCKAGE CONTROL ROOM GUIDELINE exist:

1. From Step 41 RNO, if core exit thermocouples are greater than 1200°°F and can not be reduced, to SACRG-1, SEVERE ACCIDENT CONTROL ROOM GUIDELINE INITIAL RESPONSE.

2. After completing the actions of SBCRG, the last step directs the operators to consult the plant engineering staff for further actions. Once sump blockage occurs to the extent that safeguards systems cannot maintain required recirculation flow, no credible strategy exists to reduce this blockage. Therefore, the guideline must ultimately take the plant to a condition that protects the physical barriers with reduced or alternate flow.

The SBCRG provides no provision for returning from the SBCRG to the ERG network. No effective strategy exists to remove sump blockage once it has occurred. The most likely long-term effect is increasing sump blockage as recirculation flow continues to transport debris to the sump screen. The basic strategy of the SBCRG is to maintain Critical Safety Functions (in particular, core cooling) as well as possible under these circumstances while cooling and depressurizing the RCS to conditions that no longer require recirculation flow.

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2. DESCRIPTION Recirculation sump blockage is defined as blockage of the containment recirculation sump screen to an extent that low-head SI pumps have inadequate net positive suction head (NPSH) for required flow conditions. Operators can enter guideline SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE, at two distinct times subsequent to a LOCA. The first time occurs during the switchover from the injection phase to the cold leg recirculation phase when the RWST level is below the switchover alarm setpoint but above the empty alarm setpoint. The second time occurs when the plant is already in the cold or hot leg recirculation phase and the RWST is below the empty alarm setpoint. Operators can not recognize symptoms of sump blockage before the first pumps begin operating in the recirculation alignment. Therefore, SBCRG contains no anticipatory actions to prevent or delay the effects of sump blockage. The time of entering SBCRG depends strongly on plant-specific and event-specific parameters that are difficult to predict. If the initiating event rapidly transports large amounts of debris into the sump, sump blockage could occur shortly after starting the first pump in the recirculation mode. On the other hand, a gradual buildup of debris on the screen or changing flow requirements could force operators into SBCRG some significant time after completing the recirculation alignment. The probability and consequences of recirculation sump blockage differs from plant-to-plant depending on unique design features. Each plant must evaluate their individual susceptibility to sump blockage to determine the potential effects on safeguards recirculation operation. In particular, the configuration of the containment recirculation suctions has a significant effect on responses to sump blockage. For plant designs in which low-head SI pumps and containment spray pumps take suction from a common sump, the interaction between these two types of pumps dominates early actions in the guideline. For designs in which each pump has a separate sump, early actions in the guideline become much simpler. SBCRG contains no step to “Return to Guideline and Step in effect” if recirculation capability is restored. No credible action in SBCRG restores design-basis recirculation capability. If blockage initially affects only part of the safeguards recirculation capability, continued accumulation of debris may subsequently cause loss of suction to additional safeguards pumps. Therefore, operators should remain in SBCRG rather than returning to other optimal recovery guidelines. On a plant-specific basis, if an active mechanism for reversing sump blockage exists, the SBCRG should include instructions to employ this mechanism and, if successful, return to the Guideline and Step in effect.

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The suction source of containment spray pumps in the recirculation mode is plant dependent. This guideline assumes that the spray pumps have the capability to draw water directly from the containment sump, but that operator action is required for the transfer of suction source. The reference plant Emergency Core Cooling System cold- leg recirculation alignment is shown in Figure 1. For the reference plant the design-basis minimum safeguards requirements are two high-pressure pumps (high-head SI or charging/SI) and one low-head SI pump. The low-head SI pump provides suction to the high-pressure pumps and direct injection to the RCS if the RCS pressure is low enough. The SBCRG applies only to conditions in which sump blockage makes establishing or maintaining the design-basis minimum safeguards impossible. Detailed plant specific information on this subject is generally found in the plant specific FSAR.

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Figure 1 Cold Leg Recirculation Phase

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3. RECOVERY/RESTORATION TECHNIQUE The objective of the recovery/restoration technique incorporated into guideline SBCRG is to provide the optimum ECCS flow and containment spray flow in the event of recirculation sump blockage. The following subsection provides a summary of the major categories of operator actions for guideline SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE. 3.1 High Level Action Summary A high level summary of the actions performed in SBCRG is given on the following page in the form of major action categories. These are discussed below in more detail. o Protect ECCS and CSS Pumps Loss of suction not only causes immediate loss of flow, but can also cause permanent damage to affected pumps. Therefore, the first actions of this guideline involve protecting affected pumps from the damaging effects of loss of suction. Although these actions may have a temporary negative effect on some safety functions, preserving long-term flow capability has a higher priority. Protective actions include reducing total recirculation flow (which minimizes transport of debris to the sump screen and reduces head losses to the pump suction), reducing individual pump flow (which reduces net positive suction head requirements) and, when necessary, stopping pumps. o Establish and Maintain Optimum Emergency Coolant Flow The amount of emergency coolant recirculation flow available depends on the degree of sump blockage present. In general, no means exists for directly measuring the degree of sump blockage. Therefore, operators attempt to determine the optimum flow cond itions through a trial-and-error process. In some conditions, sump blockage may make maintenance of safety functions impossible. The plant engineering staff should be consulted to determine the optimum SI and containment spray alignment. The optimum alignment may include intermittent operation of some pumps. The optimum flow conditions are those that first provide adequate core cooling and then provide

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adequate containment spray flow at the lowest possible flow rates. Flows should not be raised above the minimums necessary to support safety functions. Any additional flow produces greater transport of debris to the recirculation sump screens and increases the chances of loss of suction head. o Increase/Conserve RWST Level Makeup is added to the RWST to extend the time the SI pumps and containment spray pumps can take suction from the RWST (if pumps are taking suction from the RWST) or to permit realignment of SI pump and containment spray pump suction to the RWST (if pumps are not taking suction from the RWST). o Initiate Cooldown to Cold Shutdown A cooldown rate is established to cool the RCS to cold shutdown conditions. This permits a controlled depressurization of the RCS to limit coolant leakage. The cooldown rate is limited only to ensure controlled plant conditions during the cooldown. Thermal stresses in the reactor vessel are a minor concern for the extreme conditions associated with this guideline. The priority limits of the Integrity Status Tree do not apply. o Depressurize RCS to Minimize RCS Subcooling The RCS is depressurized to minimize RCS subcooling. Reducing RCS pressure also reduces break flow from the LOCA. o Depressurize SGs to Cool Down and Depressurize RCS A controlled RCS cooldown to cold shutdown is initiated early to decrease the overall temperature of the RCS coolant and metal in order to reduce the need for heat removal from supporting plant systems and equipment. The SGs are further depressurized to decrease the RCS pressure and temperature for the following reasons:

1) To inject the SI accumulators; 2) To minimize break flow from a LOCA; and 3) To reach RHR System conditions

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o Maintain RCS Heat Removal The RHR System (if it was placed in service), dumping of steam or SI flow to the RCS is used to maintain RCS heat removal. The plant engineering staff should be consulted for further instructions. 3.2 Key Utility Decision Points The SBCRG includes six key utility decision points, at which the utility must determine an appropriate course of action. In Step 9, the plant engineering staff is consulted to determine the optimum SI and spray alignment. At this time, the plant engineering staff must evaluate the opposing demands of increasing flow (as needed to provide core cooling and containment temperature/pressure control) and reducing flow (as needed to protect pumps, improve pump suction head margin, preserve makeup capability and minimize additional transport of debris to the recirculation sump screen). The plant engineering staff must also consider interactions between ECCS recirculation and containment spray recirculation. In Step 20, the plant engineering staff is consulted to determine the desired SI and Chemical and Volume Control Systems alignments to be established during the SI termination process. Conditions of recirculation sump blockage may require unique alignments to maintain required flow conditions. In Step 26, the plant engineering staff is consulted to determine if charging/SI pump suction should be realigned to the RWST. At this time, the plant engineering staff should determine the optimum alignment for decay heat removal and RCS inventory control. The evaluation should include considerations of restoring pump miniflow paths. In Step 30, the plant engineering staff is consulted to determine if the RHR system should be placed in service. At this time, the plant engineering staff should determine the availability of the RHR system. In Step 42, the plant engineering staff is consulted to determine if the RHR system should be placed in service. At this time, the plant engineering staff should determine the availability of the RHR system. When the guideline is completed, the last step (Step 45) directs the operators to consult the plant engineering staff, who will determine any further course of action.

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MAJOR ACTION CATEGORIES IN SBCRG

o Protect ECCS and CSS Pumps

o Establish and Maintain Optimum Emergency Coolant Flow

o Increase/Conserve RWST level

o Initiate Cooldown to Cold Shutdown

o Depressurize the RCS to Minimize RCS Subcooling

o Depressurize SGs to Cool Down and Depressurize RCS

o Maintain RCS Heat Removal

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4. DETAILED DESCRIPTION OF GUIDELINE This section provides a very detailed discussion of the generic guideline SBCRG to facilitate utility guideline writing and training efforts. By presenting guideline background information in greater detail through the use of a structured format (i.e., step description tables, step sequence tables, and logic diagrams) plant specific applicability can be more easily determined. The separate and unique subsections containing this information follow. 4.1 Detailed Description of Steps, Notes, and Cautions This section contains a one-page (or more) step description table for each separate guideline step, note, and caution. Notes and cautions are always presented relative to the step they precede. Refer to the Users Guide in the Executive Volume for a discussion on the use of the step description tables. The following pages present the Step Description Tables for the 45 steps and associated notes and cautions of guideline SBCRG.

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STEP DESCRIPTION TABLE FOR SBCRG Step1 – CAUTION 1

CAUTION: Any pump receiving suction from a low-head SI pump should be stopped before stopping the low-head SI pump.

PURPOSE: To alert the operator that any pump receiving suction from a low-head SI pump should be stopped before stopping the low-head SI pump

BASIS:

In a recirculation alignment, low-head SI pumps may provide suction to other pumps (typically high-head SI pumps and/or charging/SI pumps). Stopping a low-head SI pump under these circumstances causes almost immediate loss of suction head for the supplied pumps. Loss of suction may cause permanent damage to these high-head pumps within a very short time. Operators should stop the supplied pumps before stopping the low-head SI pump supplying suction.

ACTIONS:

o Determine if a low-head SI pump should be stopped o Determine if a low-head SI pump is supplying suction to any running pump

INSTRUMENTATION:

Position indication for valves from low-head SI pump discharge to other pump suctions

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

Effects of loss of suction on pump operation

PLANT-SPECIFIC INFORMATION:

RWST empty setpoint

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STEP DESCRIPTION TABLE FOR SBCRG Step 1 – CAUTION 2

CAUTION: If any charging/SI pump, high-head SI pump or spray pump loses suction or shows indication of cavitation, the pump should be stopped.

PURPOSE: To alert the operator that any charging/SI pump, high-head SI pump or spray pump should be stopped upon loss of its suction source or indication of cavitation

BASIS:

When any pump loses its suction source, operators must stop the pump to prevent potential pump damage. This guideline addresses loss of pump suction in the recirculation mode due to sump screen blockage. Operators must be aware of the indications of sump blockage or loss of suction head. In most plants, operators must monitor for symptoms of pump cavitation, an indirect indication of sump blockage. High-head pumps, such as high-head SI pumps and SI/charging pumps may experience permanent damage within a short time of loss of suction. Operators should immediately stop these pumps if they observe symptoms of loss of suction. Lower-head pumps, such as low-head SI pumps and spray pumps can operate with cavitation for longer times, but not indefinitely without permanent damage. If operators observe indication of cavitation with low-head SI pumps, the operators should take actions to restore suction, as described in Step 1 of this guideline, rather than immediately stopping the pump. In some cases, pumps may still be aligned to the RWST when operators enter this guideline or subsequent guideline steps may realign pump suctions to the RWST. For pumps with suction aligned to the RWST, operators should always be ready to stop running pumps if the RWST empties. This caution warns the operators to stop any charging/SI pump, high-head SI pump or spray pump if their suction source is lost (regardless of the source in use) to prevent damage to the pumps.

ACTIONS:

Determine if SI or spray pump suction source is lost.

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STEP DESCRIPTION TABLE FOR SBCRG Step 1 – CAUTION 2

INSTRUMENTATION:

RWST level indication [Plant-specific instrumentation used to diagnose cavitation/ loss of suction due to sump screen blockage: - Sump screen differential pressure - Sump water level - Pump suction pressure - Pump motor current - Pump discharge pressure - System flow]

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

Symptoms of loss of suction head/pump cavitation


RWST empty setpoint [Plant-specific parameter values characteristic of loss of suction due to sump screen blockage]

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STEP DESCRIPTION TABLE FOR SBCRG Step 1 – NOTE 1

NOTE: CSF Status Trees should be monitored for information only. FRGs should not be implemented.

PURPOSE: To alert the operator that CSF Function Restoration Guidelines are not in effect during performance of this guideline

BASIS:

Specific actions of several CSF Function Restoration Guidelines conflict with the requirements of this guideline. In particular, FR-C.1, RESPONSE TO INADEQUATE CORE COOLING, and FR-C.2, RESPONSE TO DEGRADED CORE COOLING, instruct the operator to establish or increase ECCS makeup flow to the RCS. Likewise, FR-Z.1, RESPONSE TO HIGH CONTAINMENT PRESSURE, instructs operators to establish or increase containment spray flow. Implementing these instructions with conditions of severe sump blockage could lead to permanent loss of ECCS makeup or containment spray flow capability. The intended implementation of this guideline is as a special-case guide for beyond-design-basis conditions that make impossible a success path using the Emergency Response Guidelines. This guideline provides explicit instructions for actions that support the Critical Safety Functions. In the long term, the Plant Engineering Staff must determine the actions best suited for existing plant conditions. Plants implementing guideline SBCRG as a part of their Emergency Procedures should include this note to ensure that improper transitions to CSF Function Restoration procedures do not occur. Plants implementing this guideline as special guidance outside the Emergency Procedures (in a manner similar to the Severe Accident Management Guidelines) may delete this note.

ACTIONS:

N/A

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

CSF Status Trees and associated FR guidelines do not apply when performing the SBCRG.

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N/A

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NOTE: Indications of cavitation should be monitored following any change of recirculation flow.

PURPOSE: To alert the operator that any change of recirculation flow may cause pump cavitation, either immediately at the time of increasing flow, or after a delay

BASIS:

Increasing pump flow poses both an immediate and a delayed challenge to pump operation when conditions of sump blockage exist. Increasing pump flow immediately increases NPSH requirements for the affected pump. Increasing pump flow also immediately increases head loss at the sump blockage. Increased head loss at the sump reduces the available NPSH for all pumps taking suction from the affected sump. Increasing flow through a single pump may cause cavitation in the short term for that pump or for any other pump taking suction from the same sump source. Increased pump flow may also have a delayed effect on suction conditions. Increased recirculation flow within the containment may transport additional debris to the sump screen and gradually increase the amount of blockage. In addition, for sump screens that are not completely submerged during recirculation, additional flow may draw down the level behind the screen, eventually causing air entrainment into the recirculation flow. Either of these effects may cause cavitation at some significant time after increasing the flow. Therefore, operators must be alert for indications of cavitation both immediately after increasing pump flow and for a significant time after increasing pump flow.

ACTIONS:

N/A

INSTRUMENTATION:

[Plant-specific instrumentation used to diagnose loss of suction due to sump screen blockage: - Sump screen differential pressure - Sump water level - Pump suction pressure - Pump motor current - Pump discharge pressure - System flow]

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CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

• Symptoms of loss of suction head/pump cavitation may occur immediately after increasing pump flow or after some delay following increasing pump flow.

• Raising flow through a given pump may cause loss of suction head/pump cavitation for other pumps with common suction.


N/A

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STEP DESCRIPTION TABLE FOR SBCRG Step 1

STEP: Monitor Low-Head SI Pump Suction Conditions – NO INDICATION OF CAVITATION

PURPOSE: To protect ECCS pumps from the damaging effects of cavitation/ loss of suction

BASIS:

Operators monitor plant parameters associated with low-head SI pump cavitation/loss of suction caused by sump blockage. In general, this consists of pump flow stable and appropriate for discharge conditions, pump discharge pressure stable and appropriate for flow conditions, and pump motor current stable and appropriate for flow conditions. The determination of “NO INDICATION OF CAVITATION” depends on operator knowledge and experience. If available, additional positive indications of loss of suction (such as sump screen differential pressure, internal sump water level, pump suction pressure, and computed low NPSH alarms) should be included on a plant-specific basis. If indications of low-head SI pump cavitation are observed, the operators take action to protect ECCS pumps from the damaging effects of cavitation/loss of suction. The first of these actions is to stop any charging/SI pump(s) and high-head SI pump(s) taking suction from the affected low-head SI pump(s) discharge. The reason for taking this action first is to protect the vulnerable high-head pumps from damage. Stopping these pumps also reduces total flow through the low-head SI pump(s), which improves NPSH conditions for the low-head SI pump(s). For some circumstances (e.g., small-break LOCAs) stopping the high-head ECCS pumps stops all makeup flow to the RCS. Analysis indicates that, for any time following realignment for recirculation, core uncovery and uncontrolled core heatup does not begin for some time after loss of RCS makeup flow. At this time, the overriding concern is to protect the pumps and, potentially, provide long-term makeup flow in the future. Subsequent steps direct the operators to attempt to restore and maintain RCS makeup flow by any means available. The next action is to stop any containment spray pump(s) taking suction from the same recirculation sump as the affected low-head SI pump(s). Stopping the containment spray pump(s) significantly reduces sump flow. This has an immediate benefit of reducing head loss at the sump screen and raising available NPSH for the low-head SI pump(s). The following plant-specific modifications that apply to this action: o For plants that provide containment spray recirculation flow from the discharge of low-head

SI pumps, isolate this flow. o For plants that provide separate recirculation sumps for low-head SI pumps and containment

spray pumps, stopping the spray pumps provides no benefit for low-head SI pump operation. These plants should not change the status of spray pump operation at this action.

o For plants that require spray recirculation flow for decay heat removal, modify this action to provide the necessary flow.

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STEP DESCRIPTION TABLE FOR SBCRG Step 1 The next action requires the operators to determine if indications of cavitation continue. Although pump suction conditions may change with time following significant flow changes, operators should not wait any significant time before continuing in this step. If indications of pump cavitation do not clear almost immediately, operators should continue with subsequent actions to ensure timely action to protect the pumps. If indications of cavitation continue after performing the previous actions, operators next close the RHR flow control valves. For circumstances involving low RCS pressure, this significantly reduces flow through the recirculation sump and the low-head SI pump, with associated benefits to pump suction conditions. The intent is that the operators quickly close the valves without waiting to observe for changes in pump suction conditions. Subsequent steps throttle open these valves as appropriate. Note the following plant-specific modifications that apply to this action: o Closing the RHR flow control valves requires instrument air availability and removal of SI

interlocks. This generic guideline assumes these conditions are satisfied before or during the recirculation alignment. If the conditions are not satisfied before entering this guideline, then actions to establish them must be performed before performing closing the valves.

o If closing the RHR flow control valves isolates low-head SI pump recirculation flow, then modify this action to specify a maximum closure/minimum opening.

o If flow control valves do not exist for ECCS recirculation flow, then delete this action. If indications of cavitation continue after performing the previous actions, operators next close the associated RHR injection valve(s). For many plants, closing the RHR flow control valves does not completely isolate flow. If cavitation continues with the RHR flow control valves closed, then closing the injection valves stops all flow (other than recirculation flow). This should stop cavitation caused by low net positive suction head. Since the ECCS may be in either cold-leg recirculation or hot- leg recirculation when symptoms of excessive sump blockage occur, the guideline must provide for isolating flow from each low-head SI pump to both cold- leg and hot- leg injection lines. If indication of cavitation continue with the RHR injection isolation valve(s) closed, the cavitation may be caused by phenomena other than loss of NPSH (e.g., air entrainment and subsequent air-binding). Since all actions to restore satisfactory suction conditions have failed, affected low-head SI pumps are now stopped to protect them from damage.

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ACTIONS:

o Monitor low-head SI pump suction conditions o Determine if charging/SI pump(s) and high-head SI pump(s) are taking suction from affected

low-head SI pump(s) o Stop charging/ SI pump(s) and high-head SI pump(s) o Determine if any containment spray pump(s) is taking suction from same source as affected

low-head SI pump(s) o Stop containment spray pump(s) o Determine if indications of cavitation continue o Close RHR flow control valve(s) o Close RHR injection isolation valve(s) o Stop affected low-head SI pump(s)

INSTRUMENTATION:

o Low-head SI pump flow indication o Low-head SI pump discharge pressure indication o Low-head SI pump motor current indication o [Those plants having more direct indication of loss of suction head, such as low-head SI

pump suction pressure or computed NPSH, should specify these indication] o [Those plants having direct indication of sump blockage, such as sump screen differential

pressure or water level inside the sump screen, should specify these indications] o Charging/SI pump and high-head SI pump suction valve position indication o Containment spray pump suction valve status position indication

CONTROL/EQUIPMENT:

o Charging/SI pump control switches o High-head SI pump control switches o Containment spray pump control switches o RHR flow control valve demand setpoint o RHR injection isolation control switches o Low-head SI pump control switches

KNOWLEDGE:

o This step is a continuous action step o Symptoms of pump cavitation o Alternate alignments for charging/SI pump and high-head SI pump suction o Alternate alignments for containment spray pump suctions

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o Those plants having direct indication of sump blockage, such as sump screen differential pressure or water level inside the sump screen, should provide specific criteria for determining if excessive sump blockage exists.

o Those plants having direct indication of low-head SI pump suction conditions, such as pump suction pressure or computed NPSH, should provide specific criteria for determining is pump cavitation is occurring or imminent.

o For plants that provide containment spray recirculation flow from the discharge of low-head SI pumps, provide instructions to isolate this flow.

o For plants that provide separate recirculation sumps for low-head SI pumps and containment spray pumps, delete instructions to stop containment spray pumps.

o For plants that require spray recirculation flow for decay heat removal, provide instructions to establish or maintain the necessary flow.

o If existing procedures do not establish conditions before beginning recirculation realignment to close RHR flow control valves, provide instructions to establish these conditions.

o If closing the RHR flow control valves isolates low-head SI pump recirculation flow, then modify this action to specify a maximum closure/minimum opening.

o If flow control valves do not exist for ECCS recirculation flow, then delete actions to close these valves.

03/23/2004



STEP: Verify Containment Fan Coolers – RUNNING IN EMERGENCY MODE

PURPOSE: To ensure that the containment fan coolers are running in emergency mode

BASIS:

The intent of this step is to provide containment heat removal capability using containment fan coolers and, therefore, containment spray pumps can be stopped in future steps. If the containment fan coolers are not running, the operator should manually start the fan coolers. This step applies to both normal and emergency fan coolers, i.e., those used during normal plant operation and those designed to function after a LOCA. The reference plant design provides emergency fan coolers.

ACTIONS:

o Determine if containment fan coolers are running in the emergency mode o Start fan coolers in the emergency mode

INSTRUMENTATION:

Containment fan cooler status indications

CONTROL/EQUIPMENT:

Containment fan cooler control switches

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Stop Containment Spray Pumps

PURPOSE: To stop containment spray pumps that could degrade suction conditions for SI pumps

BASIS:

This guideline assigns priority to core cooling. Efforts to restore some amount of RCS makeup flow take precedence over containment spray flow at this time. Following completion of this step, the only spray pumps that should continue running without plant engineering staff evaluation are those with sump suction independent of the ECCS sump and (for applicable plants) those required for decay heat removal. Spray pumps taking suction from the RWST are stopped to preserve inventory for use by ECCS pumps. For plants in which containment spray pumps have common recirculation suction with ECCS pumps, stop all containment spray pumps not required for decay heat removal. For plants in which containment spray pumps have recirculation suction independent of ECCS pumps, operate spray pumps in accordance with design-basis instructions. For plants that require containment spray recirculation flow for decay heat removal, this step must be modified to instruct operators to attempt to establish and maintain the required containment spray recirculation flow.

ACTIONS:

Stop containment spray pumps.

INSTRUMENTATION:

Containment spray pump status indications

CONTROL/EQUIPMENT:

Containment spray pump control switches

KNOWLEDGE:

N/A

03/23/2004




o Containment spray pumps that take suction from sources also used by ECCS pumps. o Containment spray pumps that must run for core decay heat removal.

03/23/2004



STEP: Monitor RWST Level – GREATER THAN (U.03)

PURPOSE: To protect ECCS and CSS pumps from the damaging effects of loss of suction

BASIS:

This guideline may be entered with some pumps still taking suction from the RWST. In addition, subsequent actions in this guideline may realign pump suction to the RWST. In either case, continued pump operation with suction from the RWST and RWST water level below the RWST empty alarm setpoint would lead to loss of pump suction. Operators must stop pumps before loss of suction causes pump damage. If plant-specific analysis supports operation of individual pumps taking suction from the RWST at levels less than the RWST empty alarm setpoint, then this step should be modified to allow such operation.

ACTIONS:

Determine if RWST level is greater than (U.03).

INSTRUMENTATION:

RWST level indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

This step is a continuous action step.


o (U.03) RWST empty alarm setpoint in plant specific units. o Plant-specific minimum RWST level for individual pumps taking suction from the RWST o Based on pump suction piping configuration, the plant specific value of (U.03) may need to

consider the possibility of vortexing and air entrainment.

03/23/2004



STEP: Try To Establish SI Recirculation Suction

PURPOSE: To try to establish SI recirculation suction

BASIS:

The concept of this step is that operators should attempt all available methods of establishing SI recirculation suction until either one method is successful or all methods have been demonstrated unsuccessful. The generic guideline assumes that all low-head SI pump suctions have been aligned to the recirculation sump before entering the guideline. On a plant-specific basis, if this guideline can be entered before aligning both low-head SI pump suctions to the sump, then the guideline must allow for continued suction from the RWST or realigning the suction to the sump. If any low-head SI pump is running with suction from the sump, continuous monitoring of pump suction conditions in accordance with Step 1 assures that no indications of cavitation exist. In this case, the operators close the RHR injection isolation valves. Although this may isolate a currently successful injection flow path, conditions of excessive sump blockage require efforts to restrict total recirculation flow. Subsequent steps then establish optimum flow conditions. If no low-head SI pump is running, operators first close the RHR injection isolation valves. This provides optimum (minimum flow) conditions for starting a pump. Operators then try to establish one low-head SI pump running without indications of cavitation. If attempts to establish this condition with one low-head SI pump fail, then operators attempt to establish the conditions with the redundant pump. If no low-head SI pump will run without indications of cavitation, then ECCS recirculation flow can not be established. Subsequent actions continue with Step 8, which attempts to establish ECCS makeup flow to the RCS from the RWST. The desired condition at the end of this step is to have only one low-head SI pump running with suction from the recirculation sump. One low-head SI pump can provide adequate recirculation flow. Limiting the number of running pumps prevents or delays the buildup of additional debris on the sump screen and potentially saves one pump for later use.

03/23/2004



ACTIONS:

o Determine if any low-head SI pump is running with suction from sump o Close RHR injection isolation valves o Start or stop low-head SI pumps

INSTRUMENTATION:

Low-head SI pump status indication

CONTROL/EQUIPMENT:

Low-head SI pump control switches

KNOWLEDGE:

o Closing injection isolation valves creates optimum conditions for reestablishing limited recirculation flow without cavitation

o “Miniflow” recirculation path provides low-head SI pump cooling when there is no net flow through the system.


o If recirculation flow can be established with low-head SI pump suction still aligned to the RWST, then the actions of this step must be modified to allow continued suction from the RWST or align low-head SI pump suction to the sump.

o Plants with the sump screen not fully submerged during recirculation may need to provide additional guidance on air binding and venting.

03/23/2004



STEP: Try To Establish High-Head SI In Recirculation Mode

PURPOSE: To try to establish high-head SI in recirculation mode

BASIS:

By the time of recirculation, one full train of ECCS delivers significantly more flow than the amount needed to provide core cooling. With conditions of excessive sump blockage, minimizing the SI flow provides both immediate and long-term benefits. This step attempts to establish the minimum SI flow that should keep the core covered and cooled. For the reference plant, one charging/SI pump or one high-head SI pump can deliver adequate SI flow for decay heat removal in recirculation. The intent of the step is to establish only one pump running, not one high-head SI pump plus one charging/SI pump. On a plant-specific basis, if more than one pump is required, then modify this step to obtain the required number and type of operating high-head ECCS pumps. In the long term, running a charging/SI pumps is preferred to running a high-head SI pump because the charging/SI pump allows for additional flow reductions – to normal charging flow path – as flow requirements continue to decline. When this step is performed, however, one pump of either kind is acceptable. Later steps deal with further optimization of the flow conditions. The alignment of high-head SI pump and charging/SI pump suctions must include evaluation of the running low-head SI pump and RHR flow conditions. Depending on previous valve alignments, operators may have to open RHR HX flow control valves and/or train cross-connection valves to establish a valid suction flow path. For some small-break LOCA events, RCS pressure may be greater than the shutoff head of the high-pressure SI pumps. If this results in deadheading a pump without recirculation capability, the plant-specific instructions should include directions on operating the pump.

ACTIONS:

o Determine high-head SI pump and charging/SI pump suction alignment o Align high-head SI pump and charging/SI pump suctions to running low-head SI pump o Determine number of running high-head SI pumps and charging/SI pumps o Start or stop high-head SI pumps and charging/SI pumps

INSTRUMENTATION:

o High-head SI pump and charging/SI pump suction valve position indications o High-head SI pump and charging/SI pump status indication

03/23/2004



CONTROL/EQUIPMENT:

o High-head SI pump and charging/SI pump suction valve control switches o High-head SI pump and charging/SI pump control switches

KNOWLEDGE:

N/A


Number and type of high-head SI pumps and/or charging/SI pumps required for decay heat removal in recirculation mode

03/23/2004



STEP: Try to Establish Low-Head SI Recirculation Flow

PURPOSE: To try to establish low-head SI recirculation flow

BASIS:

If high-head SI recirculation flow could not be established in the previous step, then operators attempt to establish low-head SI recirculation flow. In the reference plant, low-head SI recirculation flow is less desirable than high-head SI flow because low-head SI recirculation flow establishes higher flow rates. Higher flow rates produce greater challenges when excessive sump blockage exists. On a plant, specific basis, if low-head SI recirculation flow can be established and measured at flow rates lower than the high-head SI recirculation flow, the sequence of Step 6 and Step 7 can be reversed. Reversing the sequence of Steps 6 and 7 requires changes to the details in these steps to establish the desired alignment. This step is entered with one low-head SI pump running with suction from the recirculation sump and the low-head SI injection valves closed. After verifying that RCS pressure is less than the shutoff head of the RHR pump, the RHR flow control valves are closed (or throttled to the minimum opening that ensures recirculation flow) and the low-head SI injection valves opened. Operators next manually adjust the flow control valves to establish minimum indication of low-head SI flow to the RCS without indication of cavitation. The intent is that the flow control valves should be opened slowly while observing indications of flow and cavitation. The flow control valves should be opened only far enough to establish flow indication. Operators should not raise flow above the first positive indication of flow. Any additional flow increases the challenges associated with loss of suction head. If indications of cavitation occur before indications of flow are observed, operators should try to establish low-head SI recirculation flow with the alternate train. The instruction to “Manually adjust flow control valves” implicitly includes actions to throttle closed the valves if indicated flow is greater than the minimum positive indication or if flow conditions approach those known to cause cavitation. On a plant-specific basis, some isolation valve alignments may produce reduced flow to intact loops and excessive flow to a LOCA location. The intent of the instruction to open low-head SI injection isolation valves is to establish a flow path to all loops of the RCS. For plants with more than one injection flow path (e.g., cold-leg injection and hot- leg injection), the intent is to establish one injection flow path. On a plant-specific basis, predetermine the preferred flow path or provide instructions to determine the preferred flow path based on plant conditions. The RHR heat exchanger bypass flow control valves can be used to adjust (‘fine-tune’) flow through the system. However, using this flow path increases system flow without providing the benefit of cooling in the heat exchangers. Directing all the flow through the heat exchangers and throttling flow with the heat exchanger flow control valves (with no bypass flow) provides the optimum cooling and flow conditions.

03/23/2004



ACTIONS:

Determine that RCS pressure is less than low-head SI pump shutoff head Close RHR flow control valves Open low-head SI injection isolation valves Manually adjust flow control valves

INSTRUMENTATION:

o RCS pressure indication o Low-head SI injection flow indication o Plant-specific instrumentation used to diagnose cavitation/loss of suction due to sump screen

blockage

CONTROL/EQUIPMENT:

o RHR flow control valve demand setpoint o Low-head SI injection isolation valve control switches o Low-head SI pump control switches

KNOWLEDGE:

o The intent of this step is to open flow control valves only enough to produce the first positive flow indication.

o Instructions to “Manually adjust flow control valves” implicitly includes actions to throttle closed the valves if indicated flow is greater than the minimum positive indication or if flow conditions approach those known to cause cavitation.


o (B.07) Shutoff head of the low-head SI pumps, including allowances for normal channel accuracy

o (B.08) Shutoff head of the low-head SI pumps, including allowances for normal channel accuracy and post accident transmitter errors.

o If closing the RHR flow control valves isola tes low-head SI pump recirculation flow, then modify this action to specify a maximum closure/minimum opening.

o Low-head SI injection valve alignment that ensures flow to all loops

03/23/2004



STEP: Try To Establish High-Head SI With Suction From RWST

PURPOSE: To try to establish high-head SI flow to the RCS with suction from the RWST

BASIS:

This step is entered only if efforts to establish or restore at least some SI recirculation flow to the RCS have failed. If sufficient RWST inventory exists to support operation of a high-head ECCS pump, then one high-head SI pump or charging/SI pump is started with suction aligned to the RWST. On a plant-specific basis, if best-estimate analysis determines that high-head ECCS pumps can take suction from the RWST with RWST level less than (U.03), then the best-estimate value should be used in this step.

ACTIONS:

o Determine if RWST level is high enough to support high-head ECCS pump suction o Align high-head ECCS pump suctions to the RWST o Start or stop high-head ECCS pumps

INSTRUMENTATION:

o RWST level indication o High-head ECCS pump suction valve status indication o High-head ECCS pump status indication

CONTROL/EQUIPMENT:

o High-head ECCS pump suction valve control switches o High-head ECCS pump control switches

KNOWLEDGE:

N/A


Best-estimate of minimum RWST level required to support suction to high-head ECCS pumps

03/23/2004



STEP: Consult Plant Engineering Staff To Determine Optimum SI and Spray Alignment

PURPOSE: To consult with the plant engineering staff for optimum SI and spray alignment

BASIS:

For conditions associated with excessive recirculation sump blockage, the optimum SI and spray alignment cannot be determined in advance. In addition to plant-specific design characteristics of the sump suctions, the amount of blockage (which may not affect all pumps to the same degree) and the nature of the initiating fault affect the ability of pumps to operate in a recirculation mode. Additionally, the lack of instrumentation able to measure sump blockage directly aggravates the difficulty of determining the optimum alignment in circumstances. Therefore, the task of determining the optimum SI and spray alignment can not be assigned to operators using pre-determined procedural guidance. The plant engineering staff must evaluate observed performance of the equipment to determine available operating alignments. The evaluation must consider the potential benefits of increasing flow against the negative impacts of reduced available net positive suction head, reduced inventory of alternate suction sources, and increased transport of debris to the recirculation sump. Plant engineering staff evaluations to determine optimum SI and spray alignment may require significant time. Operators should not suspend performance of other steps in this guideline while this evaluation is being performed. Previous continuous action steps (Step 1, Monitor Low-Head SI Pump Suction Conditions – NO INDICATION OF CAVITATION, and Step 4, Monitor RWST Level – GREATER THAN (U.03)) continue to apply. Performance of subsequent steps should continue while the plant engineering staff performs the evaluation. When the plant engineering staff has determined the optimum SI and spray alignment, operators should establish the specified alignment and then continue with actions of this guideline that do not conflict with the SI and spray alignment determined by the plant engineering staff. Because of the great uncertainty associated with actual sump conditions and the possibility of changing sump conditions during an event, the plant engineering staff evaluation to determine optimum SI and spray alignment must be continuous. The consequences of any changes to SI and spray alignments should be evaluated, and pump suction conditions reevaluated frequently.

ACTIONS:

Consult plant engineering staff

03/23/2004



INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


Plant personnel comprising the “plant engineering staff”

03/23/2004



STEP: Verify No Backflow From RWST To Sump

PURPOSE: To ensure RWST fluid is not being lost to the sump

BASIS:

This step instructs the operator to verify that no backflow exists from the RWST to the sump. With RWST low level (switchover setpoint volume) coincident with an "S" signal, the sump recirculation valves open automatically (reference plant design). Since the valves from the RWST to the low-head SI pumps and the sump recirculation valves are open simultaneously at this time, back flow from the RWST to the sump may exist depending on the relative elevations. The operator is instructed to close the valves from the RWST to the low-head SI pumps as part of the switchover procedure to cold leg recirculation. This step, therefore, instructs the operator to verify the proper valve positions to ensure no backflow. Consideration was given to modifying this step to intentionally establish backflow from the RWST to the sump, with the intention of backflushing debris from the screen. It was determined not to incorporate this strategy in the generic guideline based on the following considerations: o Loss of RWST inventory depletes a source of suction for SI and spray pumps that may be

significant in responding to loss of recirculation capability. Preserving this inventory is the major concern of this step.

o Intentional alignments to backflush the screen would interfere with efforts to establish/maintain SI and spray flows.

o There is no assurance that backflow from the RWST to the sump could produce the relatively high flow velocities necessary to clear debris from the screen.

o For some types of debris, momentarily backflushing the screen and then reestablishing forward flow increases the amount of screen blockage.

ACTIONS:

o Determine if any sump recirculation valves are open o Determine if both sump recirculation valves are closed o Determine if valve from RWST to low-head SI pump in same train is closed o Close RWST to low-head SI pump valves

INSTRUMENTATION:

o Sump recirculation valve position indications o RWST to low-head SI pump valve position indication

03/23/2004



CONTROL/EQUIPMENT:

Switches for RWST to low-head SI pump valves

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Add Makeup To RWST As Necessary

PURPOSE: To add makeup to the RWST as necessary

BASIS:

This guideline may be entered with some pumps still taking suction from the RWST. In this case, adding makeup to the RWST extends the time the SI pumps and containment spray pumps (if operating) can take suction from the RWST. If all pump suctions have been transferred to a recirculation alignment, adding makeup to the RWST restores some capability for pumps to take suction from the RWST. The means of adding makeup fluid to the RWST depends on the plant specific design. Typical methods include the use of the Reactor Makeup Water Control System or the Spent Fuel Pit Cooling System.

ACTIONS:

Add makeup to the RWST as necessary

INSTRUMENTATION:

RWST level indication

CONTROL/EQUIPMENT:

Plant specific controls for adding makeup to RWST

KNOWLEDGE:

N/A


Methods of adding makeup to RWST

03/23/2004


STEP DESCRIPTION TABLE FOR SBCRG Step 12 – CAUTION

CAUTION: SI recirculation flow should not be increased to a condition that causes indication of SI pump cavitation.

PURPOSE: To alert the operator that SI recirculation flow should be controlled to prevent indication of SI pump cavitation

BASIS:

In the following step, low RVLIS indication or rising core exit TC temperatures lead to instructions to increase RCS makeup flow. Increasing recirculation flow with excessive sump blockage can lead to pump cavitation. Operators may reach this step after attempting various RCS makeup flow paths. During these attempts, the operators may have determined that some SI recirculation flow paths and flow rates cause loss of pump suction and indications of cavitation. Attempting alignments known to be ineffective in restoring flow capability or raising flow rates to values known to induce cavitation serve no purpose and may result in permanent damage to the pumps. In this situation, operators should not repeat a known failure path. This caution also includes the implicit concept that, if increasing SI recirculation flow unexpectedly causes indication of SI pump cavitation, operators should decrease the SI recirculation flow in an attempt to stop the cavitation.

ACTIONS:

N/A

INSTRUMENTATION:


CONTROL/EQUIPMENT:

N/A

03/23/2004



KNOWLEDGE:



[Plant-specific parameter values characteristic of loss of suction due to sump screen blockage]

03/23/2004


STEP DESCRIPTION TABLE FOR SBCRG Step 12 - NOTE

NOTE: Before starting any pump with suction aligned to low-head SI pumps, adequate suction path should be ensured.

PURPOSE: To ensure an adequate suction path before starting any pump with suction aligned to low-head SI pumps

BASIS:

During performance of this guideline, operators may have established non-standard alignments of the ECCS, including alignments in which non-running pumps have their suctions aligned to sources that will not provide adequate suction head for starting these pumps (e.g., a non-running low-head SI pump). Before starting any pump, operators should ensure that the pump has an adequate suction path.

ACTIONS:

N/A

INSTRUMENTATION:

Indication of pump suction valve alignment Indication of status of pumps providing suction to other pumps

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

Effect of starting or running pumps without an adequate suction path


N/A

03/23/2004



STEP: Monitor For Adequate RCS Makeup Flow

PURPOSE: To ensure RCS makeup flow is adequate

BASIS:

This step instructs the operator to verify that a makeup flow increase is not required by checking that the RVLIS full range indication is above the top of the core and that core exit TCs are stable or decreasing. This ensures that the RCS makeup flow established in previous steps provides adequate core cooling. If the makeup flow is now inadequate it will be detected in this step and operators will try to increase makeup flow. The Response Not Obtained actions provide bulleted lists of possible methods of increasing RVLIS indication and/or maintaining core exit TCs stable or decreasing. Under conditions of extreme recirculation sump blockage, one or more of these methods may be unavailable or ineffective. Operators should try the available methods until one is successful or all available methods have been found ineffective. Operators should not continue efforts to increase makeup flow to the point that indications of pump cavitation become apparent. With respect to RVLIS indication, it is sufficient to verify or establish an increasing trend.

ACTIONS:

o Determine if RVLIS indication is greater than (K.02) or (L.08), as applicable o Determine if core exit TCs are stable or decreasing o Try to increase RVLIS indication o Try to maintain core exit TCs stable or decreasing.

INSTRUMENTATION:

o RVLIS indication o Core exit TCs temperature indication o SI flow

CONTROL/EQUIPMENT:

Switches for: o High-head SI pumps o Low-head SI pumps

KNOWLEDGE:

o Understanding of RVLIS function, configuration and interpretation o This step is a continuous action step

03/23/2004




o (K.02) RVLIS full range value which is the top of the core, including allowances for instrument uncertainties.

o (L.08) RVLIS dynamic range value corresponding to an average system void fraction of 25 percent with 1 RCP running, including allowances for instrument uncertainties.

o If no RVLIS is contained in the plant specific design, then the RVLIS portion of this step may be deleted.

o As long as the RVLIS dynamic range uncertainty for the Westinghouse RVLIS design is less than +/-6%, the uncertainty does not need to be included in the calculation of the plant-specific EOP setpoints.

03/23/2004



STEP: Operate ECCS To Maintain RCS Makeup Flow Without Pump Cavitation

PURPOSE: To provide operators with flexibility in responding to conditions of excessive sump blockage

BASIS:

At this step, operators have performed or attempted pre-determined actions to protect SI pumps and spray pumps from damage, establish SI makeup to the RCS, initiated plant engineering staff to determine optimum SI and spray alignment, and begun monitoring for adequate RCS makeup flow. Subsequent changes in sump conditions may require ad-hoc responses that are extremely difficult to proceduralize. Validation test comments by operators emphasized several cases in which initial actions established acceptable RCS makeup flow rates, but later changes led to cavitation. The operators were able to perform actions to protect the pumps but could not restore RCS makeup flow. The operators stated that they knew what should be done, based on observed plant responses to previous actions, but could not reach the desired status by verbatim compliance with the guideline. Therefore, this step provides guidance allowing operators to perform as-hoc actions to maintain the desired plant conditions in extreme circumstances for which procedural guidance fails. Plants intending to implement this guidance as a part of their Emergency Procedures should delete this step or modify it to provide explicit instructions for all possible combinations of sump blockage, equipment availability and event sequences.

ACTIONS:

o Start or stop pumps as required o Align flow paths as required o Throttle flow as required

03/23/2004



INSTRUMENTATION:

o SI pump flow indicators o [Plant-specific instrumentation used to diagnose loss of suction due to sump screen blockage:

- Sump screen differential pressure - Sump water level - Pump suction pressure - Pump motor current - Pump discharge pressure - System flow]

o SI pump status indication o [Plant-specific position indication for valves used to align SI pump flow paths] o [Plant-specific position indication for valves capable of throttling SI flow]

CONTROL/EQUIPMENT:

o SI pump control switches o [Plant-specific control switches for valves used to align SI pump flow paths] o [Plant-specific controls for valves capable of throttling SI flow]

KNOWLEDGE:



o Alternate flow paths available for maintaining RCS makeup flow o Methods of throttling RCS makeup flow

03/23/2004



STEP: Monitor For RCS Makeup Capability

PURPOSE: To determine if RCS makeup capability exists

BASIS:

Previous actions to protect pumps from cavitation may have created a condition in which no RCS makeup capability exists. If this condition exists, the operator is instructed to try to restore RCS makeup capability. If RCS makeup capability can not be restored, then the operator is directed to Step 34 to initiate alternate means of restoring RCS inventory.

ACTIONS:

Monitor for RCS makeup capability

INSTRUMENTATION:

o Charging/SP pump flow indication o High-head SI pump flow indication o Low-head SI pump flow indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

This step is a continuous action step


N/A

03/23/2004



STEP: Check RCS Pressure: GREATER THAN (B.07) PSIG [(B.08) FOR ADVERSE CONTAINMENT]

PURPOSE: To determine if secondary system cooldown and depressurization of the RCS is required

BASIS:

Steps 16 through 38 direct actions for a controlled cooldown and depressurization of the RCS. If RCS pressure has already declined below the shutoff head for the low-head SI pumps, these actions are unnecessary.

ACTIONS:

Determine if RCS pressure is greater than (B.07) [(B.08) for adverse containment]

INSTRUMENTATION:

RCS pressure indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


o (B.07) Shutoff head pressure of the low-head SI pumps, including allowance for normal channel accuracy

o (B.08) Shutoff head pressure of the low-head SI pumps, including allowance for normal channel accuracy and post accident transmitter errors

03/23/2004


STEP DESCRIPTION TABLE FOR SBCRG Step 16 - CAUTION

CAUTION: Alternate water sources for AFW pumps will be necessary if CST level decreases to less than (U.01).

PURPOSE: To alert the operator that CST level should be monitored, and that an alternate supply may be necessary

BASIS:

If CST level decreases below (U.01), inadequate suction pressure may result in AFW pump trip. An alternate suction source should be provided.

ACTIONS:

Determine if CST level decreases to less than (U.01)

INSTRUMENTATION:

CST level indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


o (U.01) CST low level switchover setpoint in plant specific units o Alternate suction source for AFW pumps

03/23/2004



STEP: Check Intact SG Levels

PURPOSE: To ensure adequate feed flow or SG inventory for secondary heat sink requirements

BASIS:

The minimum feed flow requirement ensures adequate heat removal capability until level in at least one SG is restored into the narrow range. Narrow range level is reestablished in all SGs to maintain symmetric cooling of the RCS. The control range ensures adequate inventory with level readings on span.

ACTIONS:

o Determine if SG narrow range level greater than (M.02)% [(M.03)% for adverse containment]

o Determine if narrow range level in any SG continues to increase o Maintain total feed flow greater than (S.02) gpm until narrow range level greater than

(M.02)% [(M.03)% for adverse containment] in at least one SG o Control feed flow to maintain narrow range level between (M.02)% [(M.03)% for adverse

containment] and 50% o Stop feed to SG where narrow range level continues to increase

INSTRUMENTATION:

o SG narrow range level indication o Total feed flow indication o Feed flow control valves position indication

CONTROL/EQUIPMENT:

Feed flow control valve switches

KNOWLEDGE:


03/23/2004




o (M.02) SG level just in the narrow range, including allowances for normal channel accuracy and reference leg process errors.

o (M.03) SG level just in the narrow range, including allowances for normal channel accuracy, post accident transmitter errors, and reference leg process errors, not to exceed 50%.

o (S.02) The minimum safeguards AFW flow requirement for heat removal, including allowances for normal channel accuracy (typically one MD AFW pump capacity at SG design pressure). This flow is equivalent to the minimum AFW flow design requirement that must be delivered to the intact steam generators as assumed in the main feedline break safety analysis.

03/23/2004



NOTE: Shutdown margin should be monitored during RCS cooldown.

PURPOSE: To determine if shutdown margin is adequate for RCS cooldown

BASIS:

This note advises the operator to monitor RCS boron concentration to verify adequate shutdown margin during the cooldown to cold shutdown. Note that since SI was in service, RCS boron concentration is expected to be sufficient. However, use of alternate suction sources for ECCS pumps may introduce unborated water and reduce the RCS boron concentration.

ACTIONS:

N/A

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

Periodic samples should be taken to monitor shutdown margin. However, the operator should not wait for the sample results before initiating or continuing the cooldown to cold shutdown.


N/A

03/23/2004



NOTE: Low steamline pressure SI signal should be blocked when PRZR pressure decreases to less than (A.05) psig.

PURPOSE: To prevent main steamline isolation valve (MSIV) closure on low compensated steamline pressure during controlled RCS cooldown

BASIS:

The SI actuation signal on low steamline pressure can be blocked during cooldown once the PRZR pressure decreases to the P-11 setpoint (approximately 2000 psig). This prevents MSIV closure, thus allowing cooldown by (the preferred method of) steam dump to condenser..

ACTIONS:

o Determine if PRZR pressure decreases to less than (A.05) psig o Block low steamline pressure SI signal

INSTRUMENTATION:

PRZR pressure indication

CONTROL/EQUIPMENT:

Controls to block low steamline pressure SI signal

KNOWLEDGE:

N/A


(A.05) PRZR pressure permissive to block low steamline pressure SI (P-11).

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NOTE: After the low steamline pressure SI signal is blocked, main steamline isolation will occur if the high steam pressure rate setpoint is exceeded.

PURPOSE: To alert the operator to the potential for inadvertent steamline isolation during the subsequent steam generator depressurization

BASIS:

An automatic protection feature is provided to close the main steamline isolation valves when the steam pressure rate signal is exceeded. In the following step, the operator is instructed to dump steam from the intact steam generators. This action may result in exceeding the rate setpoint. Therefore, this note is intended to alert the operator of this possibility.

ACTIONS:

N/A

INSTRUMENTATION:

MSIV position indication

CONTROL/EQUIPMENT:

Atmospheric steam dump valve controls

KNOWLEDGE:

The rapid cooldown should be continued using the atmospheric steam dumps if MSIV closure occurs.


This note may be written to warn the operator not to exceed a certain cooldown rate to prevent MSIV closure.

03/23/2004



NOTE: Previous temperature changes should not be considered when establishing desired cooldown rate.

PURPOSE: To alert the operator that the cooldown in the following step should be governed by the specific instruction of the step rather than the limits of ERGs associated with reactor vessel integrity

BASIS:

Step 17 instructs the operator to initiate a cooldown with the cooldown rate in the RCS cold legs limited to less than 100 °F/hour. This cooldown rate was selected only to ensure a controlled cooldown process. Previous operator training and experience associates the specified cooldown rate with concerns for reactor vessel integrity, in which the operators are instructed to not cool down by more than 100 °F in any one hour. For the circumstances of this guideline, actions to cool down and depressurize the RCS have a higher concern than those of reactor vessel integrity. Therefore, concerns of cooling down by more than 100 °F in any one hour do not apply. This Note informs operators that the cooldown should be started immediately without considering any previous temperature changes.

ACTIONS:

N/A

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

Cooldown to cold shutdown should not be delayed by imposing limits inapplicable to this guideline.


N/A

03/23/2004



STEP: Initiate RCS Cooldown To Cold Shutdown

PURPOSE: To begin a controlled RCS cooldown to cold shutdown temperature using a preferred or alternate method with a specified maximum cooldown rate

BASIS:

The objective of a controlled cooldown is to reduce the overall temperature of the RCS coolant and metal to reduce the need for supporting plant systems and equipment required for heat removal. The maximum cooldown rate of 100 °F/hr is established to ensure a controlled cooldown process. The preferred steam release path is to the condenser to conserve inventory; however, atmospheric release is the stated alternative. If the operator cannot dump steam from intact SGs to the condenser or by using PORVs, the operator should use any other plant specific means of removing water or steam from the intact SGs. This could include opening the blowdown lines or operation of the steam driven AFW pump. If no intact SGs are available, the step instructs the operator to use a faulted SG.

ACTIONS:

o Determine if no intact SG is available o Initiate RCS cooldown to cold shutdown o Maintain cooldown rate in RCS cold legs less than 100 °F/hr o Dump steam to the condenser from intact SGs o Dump steam to the atmosphere from intact SGs using SG PORVs o Dump steam from intact SGs using other plant specific means o Dump steam from faulted SG

INSTRUMENTATION:

o RCS hot leg temperatures indication o RCS cold leg temperatures indication o Steam dump valves to condenser position indication o SG PORVs position indication o Plant specific instrumentation to indicate dumping steam by other means

CONTROL/EQUIPMENT:

o Steam dump valves to condenser switches o SG PORVs switches o Plant specific controls to dump steam by other means

03/23/2004



KNOWLEDGE:

o To minimize offsite releases, the cooldown rate should be maximized to cooldown as quickly as possible not to exceed 100°F/HR.

o Cooldown limits associated with reactor vessel integrity concerns do not apply during performance of this guideline.

o Possible upper head void formation due to cooling down at this rapid rate is not a concern in this guideline since a loss of coolant accident already exists.


Other means of dumping steam

03/23/2004


STEP DESCRIPTION TABLE FOR SBCRG Step 18 - CAUTION

CAUTION: If RCP seal cooling had previously been lost, the affected RCP(s) should not be started prior to a status evaluation.

PURPOSE: To alert the operator that RCP seal damage may have occurred if RCP cooling had previously been lost. In that case, starting the affected RCP may further damage the seal and RCP

BASIS:

The potential for degradation in RCP seal performance and seal life increases with increasing temperature above 300 °F. Hence, if RCP seal cooling is lost for a significant period of time, seal and/or bearing damage may occur. The potential non-uniform sealing surfaces and seal crud blockage that may exist prior to RCP start can aggravate bearing and seal damage if the RCP is started. Following restoration of seal cooling, the RCP should not be started prior to a complete RCP status evaluation in order to minimize potential RCP damage on restart. Refer to Subsection 2.1 of the background document for guideline ECA-0.0, LOSS OF ALL AC POWER, for additional information.

ACTIONS:

Determine if RCP seal cooling had been lost

INSTRUMENTATION:

RCP seal injection flow indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

o If RCP seal cooling is lost for only a few minutes, the inventory of cold water in the seal area should prevent excessive seal heat up. For longer periods of time, seal and bearing temperatures may increase greater than 300 °F. If excessive temperatures develop, the affected RCP should no t be restarted prior to a complete RCP evaluation.

o RCPs should not be started prior to a status evaluation.


N/A

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NOTE: RCPS should be run in order of priority to provide normal PRZR spray.

PURPOSE: To inform the operator of a preferred order for starting (or stopping) RCPs

BASIS:

For the reference plant, there are PRZR connections to one RCS hot leg via the surge line and to two RCS cold legs via the spray lines. Single pump operation in the loop that provides the best spray is preferred to obtain normal PRZR spray capability. If the RCP in the loop with the pressurizer surge line can be started, then it alone should be sufficient to provide normal pressurizer spray. However, if that RCP is unavailable, it will likely be necessary to start more than one RCP to provide normal pressurizer spray. Refer to the document RCP TRIP/RESTART in the Generic Issues section of the Executive Volume.

ACTIONS:

N/A

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


Which RCPs can provide spray and the preferred order of operation

03/23/2004



STEP: Check If An RCP Should Be Started

PURPOSE: To determine the appropriate RCP operation

BASIS:

Forced coolant flow is the preferred mode of operation to allow for normal RCS cooldown and provide PRZR spray. If RCPs had not been tripped, all RCPs not required for normal PRZR spray but one are now stopped to minimize heat input to the RCS. The RCP(s) started or left running should be selected to one that can provide normal PRZR spray (see preceding note). If no RCP is running, RCS subcooling, and certain plant specific conditions are required before starting an RCP. Depressurization of the RCS may generate a steam bubble in the upper head region of the reactor vessel if no RCP is running. This bubble could rapidly condense during pump startup, drawing liquid from the pressurizer and reducing reactor coolant subcooling. In addition, local flashing of reactor coolant could occur if RCS subcooling is not adequate. If all seal cooling has been lost long enough that the maximum RCP seal parameters identified in the RCP Vendor Manual have been exceeded, seal injection and CCW thermal barrier cooling should not be established to the affected RCP(s). Both of these methods of seal cooling could have unintended consequences that result in additional pump damage or the failure of plant safety systems. Seal cooling should instead be restored by cooling the RCS, which will reduce the temperature of the water flowing through the pump seals.

ACTIONS:

o Determine if all RCPs are stopped o Determine if RCS subcooling based on core exit TCs is greater than (R.01) °F [(R.02) °F for

adverse containment] o Stop all RCP(s) not required for normal PRZR spray (if more than one RCP running) o Establish conditions for starting an RCP o Start one RCP in loop with surge line o Start RCPs to provide normal PRZR spray

INSTRUMENTATION:

o RCP status indication o RCS pressure indication o Core exit TCs temperature indication o RCP support conditions status indications

03/23/2004



CONTROL/EQUIPMENT:

o RCP switches o RCP support equipment controls

KNOWLEDGE:

Plant specific procedures for starting an RCP may require a steam bubble to be present in the PRZR. RCP restart should be permitted if an RCS leak path is certain since the leak ensures that there will not be a significant pressure surge when the RCP is started.


o (R.01) The sum of temperature and pressure measurement system errors, including allowances for normal channel accuracies, translated into temperature using saturation tables.

o (R.02) The sum of temperature and pressure measurement system errors, including allowances for normal channel accuracies and post accident transmitter errors, translated into temperature using saturation tables.

o Support conditions for starting an RCP

03/23/2004



STEP: Check If SI Is In Service

PURPOSE: To determine if any high-head SI pump is running, if any charging/SI pump is injecting through the BIT or if any low-head SI pump is running in the SI mode

BASIS:

If SI is in service (either high pressure or low pressure pumps), Step 20 will determine if SI can be terminated. If SI is not in service, either SI has already been terminated or SI can not be terminated and long-term RCS inventory strategies must be determined by the plant engineering staff.

ACTIONS:

o Determine if any high-head SI pumps are running o Determine if BIT is not isolated o Determine if any low-head SI pumps are running in the SI mode

INSTRUMENTATION:

o High-head SI pump status indication o BIT inlet and outlet isolation valve position indication o Low-head SI pump status indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Check If SI Can Be Terminated

PURPOSE: To determine if conditions have been established that indicate that one train of SI flow is no longer required and SI makeup to the RCS replaced by normal charging flow

BASIS:

Following the reduction to one train of SI, RCS conditions may be within acceptable limits for SI termination to be allowed. The combination of a minimum subcooling and sufficient liquid level in the vessel to cover the core represents less restrictive SI termination criteria in this guideline because SI flow may prevent a subsequent reduction in RCS pressure and cause considerable depletion of the RWST. The subcooling criterion will ensure subcooled conditions and the RVLIS indication ensures the existence of an adequate vessel inventory such that core cooling is ensured. Refer to document SI TERMINATION/REINITIATION in the Generic Issues section of the Executive Volume. The requirement for having at least one charging/SI pump running provides a known initial status for the SI termination sequence and assures the ability to provide makeup to the RCS through the normal charging flow path when SI has been terminated. The possibility of abnormal pump alignments requires this check. If no charging/SI pump is running, the operator consults with the plant engineering staff to determine the desired SI termination sequence. If the termination criteria are not satisfied, then SI is required to ensure core cooling and should not be terminated. If RVLIS indication is adequate but RCS subcooling is not, the operator is then instructed to try to establish the minimum SI pump flow needed to match decay heat in order to further decrease SI pump flow and delay RWST depletion. This is done by aligning (if necessary) and operating the appropriate SI pumps (charging/SI pumps, high-head SI pumps and low-head SI pumps) such that the flow required to match decay heat is established. For most Westinghouse plants, the flow through the SI lines cannot be throttled and the exact flow rate required cannot be established. Therefore, in order to establish the minimum SI flow required in this step, the operator should stop appropriate SI pump(s) to establish flow equal to or greater than the minimum SI flow required to match decay heat. The SI flow needed to match decay heat is a function of time and is obtained from Figure 2. In trying to establish minimum SI flow, the operator should not increase flow to a condition that causes indications of pump cavitation.

03/23/2004


STEP DESCRIPTION TABLE FOR SBCRG Step 20 Figure 2 is a generic curve with units for flowrate of gpm per MWt. Each utility must develop a plant specific curve for its plant from Figure 2. This curve would be included in the plant specific SBCRG as Figure SBCRG-1. This plant specific curve can be developed by modifying Figure 2 as follows: The Y-axis values for flowrate in gpm/MWt should be multiplied by the plant specific MWt core rating to obtain flowrate values in GPM. The X-axis values for time in minutes are used without modification. A plant specific curve is then plotted as flowrate (gpm) versus time (minutes). Note that Figure SBCRG-1 in guideline SBCRG has been developed for a plant with a core rating of 3411 MWt and is included as an example. Because sump blockage conditions may require unique alignments of the SI and Chemical & Volume Control Systems, the plant engineering staff must evaluate the alignments of these systems desired at the end of the SI termination process.

ACTIONS:

o Determine if RVLIS indication is greater than (K.02) or (L.08), as applicable. o Determine if RCS subcooling (based on core exit TCs) is greater than (R.12) °F [(R.13) °F

for adverse containment] o Determine if at least one charging/SI pumps is running o Determine minimum SI flow required from Figure SBCRG-1 o Establish minimum SI flow without causing indications of cavitation

INSTRUMENTATION:

o RVLIS indication o RCS pressure indication o Core exit TCs temperature indication o Charging/SI pumps status indication o [Plant-specific instrumentation used to diagnose cavitation/loss of suction due to sump screen

blockage: - Sump screen differential pressure - Sump water level - Pump suction pressure - Pump motor current - Pump discharge pressure - System flow]

CONTROL/EQUIPMENT:

o High-head SI pump switches o Charging/SI pump switches o Low-head SI pump switches

03/23/2004


STEP DESCRIPTION TABLE FOR SBCRG Step 20 KNOWLEDGE: o Understanding of RVLIS function, configuration, and interpretation o Due to the less restrictive SI termination and reinitiation criteria provided in this guideline

the operator should be especially alert for any decrease in RCS subcooling or vessel level that warrants SI reinitiation

o Understanding indications of pump cavitation o This step is a continuous action step



o (L.08) RVLIS dynamic range value corresponding to an average system void fraction of 25 percent with one RCP running, including allowances for instrument uncertainties.

o (R.12) The sum of temperature and pressure measurement system errors, including allowances for normal channel accuracies, translated into temperature using saturation tables, plus 50 °F.

o (R.13) The sum of temperature and pressure measurement system errors, including allowances for normal channel accuracies and post accident transmitter errors, translated into temperature using saturation tables, plus 50 °F.

o If RVLIS is not available, RCS subcooling based on core exit TCs is sufficient for terminating SI since a 50 °F margin has been added to instrument uncertainties. This 50°F margin allows sufficient time for operator action to reinitiate SI before core uncovery.


o Plant personnel comprising the “plant engineering staff”

03/23/2004


Figure 2 Decay Heat Flow Rate Per MWt Versus Time After Trip

03/23/2004



STEP: Reset Containment Isolation Phase A And Phase B

PURPOSE: To remove the “locked- in” signal causing all Phase A and Phase B containment isolation valves to be closed, so that equipment can be realigned

BASIS:

This part of the automatic logic requires a deliberate operator action to remove the "close" signal. No valve will reposition upon actuation of the resets, but subsequent control actions will open the valves. These valves should remain closed, unless necessary process streams are being established, until the cause of the SI is determined or corrected.

ACTIONS:

o Reset Containment Isolation Phase A o Reset Containment Isolation Phase B

INSTRUMENTATION:

o Containment Phase A indication o Containment Phase B indication

CONTROL/EQUIPMENT:

o Containment Phase A reset switch o Containment Phase B reset switch

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Establish Instrument Air To Containment

PURPOSE: To restore a sustained compressed air supply to allow control of air-operated equipment inside containment (e.g., charging and letdown valves, PRZR PORVs, etc.)

BASIS:

The instrument (control) air system for the reference plant utilizes a large volume receiver to sustain pressure in the system. A separate receiver inside containment allows limited equipment operation; however, the line to the compressors is isolated with Phase A isolation. While opening the containment valves provides a flow path, a compressor may also have to be started (with attendant electrical considerations) to supply pressure.

ACTIONS:

o Establish instrument air to containment o Start one air compressor and establish instrument air to containment

INSTRUMENTATION:

o Containment isolation valve position indications o Air pressure indications o Compressor status indications

CONTROL/EQUIPMENT:

o Containment isolation valve switches o Air compressor control switch

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Stop SI Pumps And Place In Standby

PURPOSE: To establish the optimum number and type of running ECCS pumps for SI termination

BASIS:

Satisfaction of conditions for SI termination implies that control can be maintained by the operator without all of the ECCS pumps running. In a recirculation alignment, the running low-head SI pump supplies the running charging/SI pump. Therefore, the operator does not stop any running low-head SI pump at this time. Running low-head SI pumps will be stopped in a later step after ensuring no other pumps are receiving suction from the low-head SI pumps. In this step, any running high-head SI pump and all but one running charging/SI pump are stopped and placed in standby for possible future use.

ACTIONS:

o Stop high-head SI pumps and place in standby o Stop all but one charging/SI pump and place in standby

INSTRUMENTATION:

o High-head SI pump status indication o Charging/SI pump status indication

CONTROL/EQUIPMENT:

o High-head SI pump controls o Charging/SI pump status indication

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Isolate BIT

PURPOSE: To stop injection flow to the RCS through the BIT

BASIS:

Normal charging and the BIT injection lines are parallel flow paths from the discharge of the charging/SI pumps. BIT isolation enables the normal charging path to be used. Closing the inlet valves first prevents any pressure surge in the BIT. Prior to opening the charging/SI pump miniflow isolation valves, the operator checks to determine if the charging/SI pumps are aligned to the RWST in the injection mode or to the discharge of the low-head SI pumps in the recirculation mode. If the charging/SI pumps are aligned to the RWST, the miniflow isolation valves should be opened. If the charging/SI pumps are aligned to the discharge of the low-head pumps in the recirculation mode, the miniflow valves should not be opened since this will, for certain conditions, establish a flow path from the containment sump through the low-head SI pumps via the CVCS relief valves to the CVCS holdup tanks. For the recirculation mode, the operator opens the charging flow control valve to establish a minimum charging flow prior to isolating the BIT.

ACTIONS:

o Determine if charging/SI pump suction is aligned to the RWST o Determine if charging/SI pump suction is aligned to the discharge of low-head SI pumps o Close charging line hand control o Open charging line isolation valves o Open charging flow control valve (S.06)% o Close BIT inlet and outlet isolation valves o Establish and maintain (S.01) gpm charging flow using charging flow control valve and

charging line hand control valve o Determine if charging/SI pump miniflow isolation valves are open o Open charging/SI pump miniflow isolation valves o Close BIT inlet isolation valves o Close BIT outlet isolation valves

03/23/2004



INSTRUMENTATION:

o Charging/SI pump suction valves position indication o Low-head SI pumps position indication o Charging line hand control valve position indication o Charging line isolation valves position indication o Charging flow control valve position indication o Charging flow indication o Charging/SI pump miniflow isolation valve position indications o BIT inlet and outlet valve position indications

CONTROL/EQUIPMENT:

o Charging line hand control valve control o Charging line isolation valves controls o Charging flow control valve control o Charging/SI pump miniflow isolation valve controls o BIT inlet and outlet valve controls

KNOWLEDGE:

N/A


o (S.01) Charging flow rate comparable to normal charging/SI pump miniflow. o (S.06) Value corresponding to the charging flow control valve position to ensure minimum

charging flow when the BIT is isolated.

03/23/2004



STEP: Establish Charging Flow

PURPOSE: To properly establish a charging path and charging flow

BASIS:

Proper alignment of the charging path allows flow to be controlled in the normal manner. For the reference plant, normal miniflow for the charging/SI pump does not isolate on an SI signal and miniflow will be available since miniflow was verified in the previous step before the BIT was isolated. Charging flow is established by closing the charging line hand control valve, opening the charging line isolation valves and then establishing the desired charging flow by adjusting the charging line flow control valve and the charging line hand control valve. For those plants that have miniflow isolated on an SI signal, miniflow should be reestablished before isolating the BIT. The substeps in this step are an example of how to establish charging and may be modified, as long as a minimum seal injection flow is maintained and charging is introduced cautiously through the charging line.

ACTIONS:

o Close charging line hand control valve o Open charging line isolation valves o Establish desired charging flow using charging flow control valve and charging line hand

control valve

INSTRUMENTATION:

o Position indication for: - Charging line flow control valve - Charging line hand control valve - Charging line isolation valves

o Charging flow indication

CONTROL/EQUIPMENT:

Controls for: o Charging line flow control valve o Charging line hand control valve o Charging line isolation valves

03/23/2004



KNOWLEDGE:

Charging/SI pump suction transfers to the RWST on an SI signal. If normal charging conditions are desired, suction must be transferred back to the VCT. If charging requirements exceed VCT makeup capabilities, suction will automatically transfer back to RWST on VCT low level.


o Miniflow status following SI o Means to establish charging

03/23/2004



STEP: Check If Charging/SI Pump Should Be Realigned To RWST

PURPOSE: To realign charging/SI pump suction from low-head SI pump discharge to the RWST

BASIS:

If adequate RWST inventory exits to support long-term charging/SI pump operation, then transferring the charging/SI pump suction allows stopping the low-head SI pumps taking suction from the sump. This, in turn, removes concerns with loss of suction caused by sump screen blockage. Abnormal configurations that may have been created during attempts to maintain RCS makeup flow with containment sump blockage. Because of this, the plant engineering staff should be consulted to determine if charging/SI pump suction should be realigned to the RWST.

ACTIONS:

o Determine RWST level o Determine RWST refill rate o Open charging/SI pump suction valves from RWST o Close charging/SI pump suction valves from low-head SI pump o Consult plant engineering staff

INSTRUMENTATION:

o RWST level indications o RSWT makeup flow indications o Charging flow indications o Charging pump suction valve position lights

CONTROL/EQUIPMENT:

Control switches for charging/SI pumps suction valves

KNOWLEDGE:

N/A


Plant personnel comprising the “plant engineering staff”

03/23/2004



STEP: Check If Running Low-head SI Pump Should Be Stopped

PURPOSE: To stop ECCS suction flow from the recirculation sump

BASIS:

Because abnormal configurations may have been created during efforts to maintain SI makeup flow to the RCS with sump blockage conditions, operators may reach this step of the guideline with a running charging/SI pump taking suction from a low-head SI pump. Only after determining that SI can be terminated, stopping any running high-head SI pump and ensuring no charging/SI pump is taking suction from a running low-head SI pump can operators safely stop the running low-head SI pump.

ACTIONS:

o Determine if running charging pump suction is aligned to low-head SI pump o Stop running low-head SI pump and place in standby

INSTRUMENTATION:

o Charging/SI pump suction valves position indication o Charging/SI pump status indication o Low-head SI pump status indication

CONTROL/EQUIPMENT:

Low-head SI pump controls

KNOWLEDGE:

N/A


N/A

03/23/2004



CAUTION: SI recirculation flow should not be increased to a condition that causes indication of SI pump cavitation.

PURPOSE: To alert the operator that SI recirculation flow should be controlled to prevent indication of SI pump cavitation

BASIS:

In the following step, low RVLIS indication or increasing core exit TC temperatures lead to instructions to increase ECCS flow. Increasing ECCS recirculation flow with excessive sump blockage can lead to pump cavitation. Operators may reach this step after attempting various ECCS flow paths. During these attempts, the operators may have determined that some ECCS flow paths and flow rates cause loss of pump suction and indications of cavitation. Attempting alignments known to be ineffective in restoring flow capability or raising flow rates to values known to induce cavitation serve no purpose and may result in permanent damage to the pumps. In this situation, operators should not repeat a known failure path. This caution also includes the implicit concept that, if increasing SI recirculation flow unexpectedly causes indication of SI pump cavitation, operators should decrease the SI recirculation flow in an attempt to stop the cavitation.

ACTIONS:

N/A

INSTRUMENTATION:


CONTROL/EQUIPMENT:

N/A

03/23/2004



KNOWLEDGE:



Plant-specific parameter values characteristic of loss of suction due to sump screen blockage

03/23/2004



NOTE: Before starting any pump with suction aligned to low-head SI pumps, adequate suction path should be ensured.

PURPOSE: To ensure an adequate suction path exists before starting any pump with suction aligned to a low-head SI pump

BASIS:

During performance of this guideline, operators may have established non-standard alignments of the ECCS, including alignments in which non-running pumps have their suctions aligned to sources that will not provide adequate suction head for starting these pumps. Before starting any pump, operators should ensure that the pump has an adequate suction path.

ACTIONS:

N/A

INSTRUMENTATION:

Indication of pump suction valve alignment Indication of status of low-head SI pumps providing suction to other pumps

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

Effect of starting or running pumps without an adequate suction path


Pumps that may be aligned to take suction from a low-head SI pump

03/23/2004



STEP: Monitor For Adequate RCS Makeup Flow

PURPOSE: To ensure RCS makeup flow is adequate

BASIS:

This step instructs the operator to verify that a makeup flow increase is not required by checking that the RVLIS full range indication is above the top of the core and that core exit TCs are stable or decreasing. This ensures that the makeup flow reduction performed in the previous steps was done properly; i.e., if the makeup flow is now inadequate due to the actions of Steps 20 through 27, it will be detected in this step and makeup flow will be increased. The Response Not Obtained actions provide bulleted lists of possible methods of increasing RVLIS indication and/or maintaining core exit TCs stable or decreasing. Under conditions of extreme recirculation sump blockage, one or more of these methods may be unavailable or ineffective. Operators should try the available methods until one is successful or all available methods have been found ineffective. Operators should not continue efforts to increase makeup flow to the point that indications of pump cavitation become apparent. With respect to RVLIS indication, it is sufficient to verify or establish an increasing trend. The content of this step is identical to that of Step 12. Although Step 12 is a continuous action step, repeating this guidance was considered appropriate at this stage of the guideline because of the actions performed in Steps 20 through 27.

ACTIONS:

o Determine if RVLIS indication is greater than (K.02) or (L.08), as applicable o Determine if core exit TCs are stable or decreasing o Increase RCS makeup flow to maintain RVLIS indication as applicable o Increase RCS makeup flow to maintain core exit TCs stable or decreasing

INSTRUMENTATION:

o RVLIS indication o Core exit TCs temperature indication o RCS makeup flow indication

03/23/2004



CONTROL/EQUIPMENT:

Switches for: o High-head SI pumps o Low-head SI pumps

KNOWLEDGE:

o Understanding of RVLIS function, configuration and interpretation o This step is a continuous action step




o If no RVLIS is contained in the plant-specific design, then the RVLIS portion of this step may be deleted.


03/23/2004



NOTE: The upper head region may void during RCS depressurization if RCPs are not running. This will result in a rapidly rising PRZR level.

PURPOSE: To inform the operator that voiding in the upper head region may cause rapidly increasing pressurizer level during RCS depressurization with no RCPS running

BASIS:

During a depressurization, the hotter regions of the RCS (upper head) tend to void and cause rapidly increasing pressurizer level. This effect is more likely to occur when RCPs are not running.

ACTIONS:

N/A

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Depressurize RCS To Decrease RCS Subcooling

PURPOSE: To decrease RCS pressure to the lowest possible without losing subcooling

BASIS:

The RCS pressure reduction performed in this step decreases RCS break flow for small break LOCAs when the RCS is in a subcooled condition. The intent of the depressurization is to decrease RCS pressure to the lowest pressure possible without losing subcooling. For large break LOCAs, the RCS would already be depressurized, RCS subcooling would not exist and operators should not perform this step should. Upon entering this step, the operator first checks RCS subcooling. If RCS subcooling is not adequate, the operator proceeds to the next step and does not perform this step. If RCS subcooling is adequate, the operator performs the remainder of this step. The operator should depressurize the RCS until RCS subcooling is between (R.01) °F [(R.02) °F for adverse containment] and (R.08) °F [(R.09) °F for adverse containment]. If the operator uses a PORV to depressurize the RCS and RCS subcooling decreases to less than (R.01) °F [(R.02) °F for adverse containment] before a PORV is closed or isolated, the operator should allow adequate time for the PORV or its associated block valve to close (i.e., the time necessary for the valve to stroke) before increasing RCS makeup flow to restore subcooling. If normal PRZR spray is not available, and the RCS cannot be depressurized using any PRZR PORV, then the step instructs the operator to use auxiliary spray. This preferred order of the means to depressurize the RCS takes into account that the operator has not yet established letdown to heat the auxiliary spray flow and minimize the thermal shock to the spray nozzle. A second criterion, in addition to subcooling, for stopping the pressure reduction is PRZR level greater than (D.08)% [(D.09)% for adverse containment]. Limiting PRZR level ensures a substantial steam bubble, which facilitates further pressure control.

03/23/2004



ACTIONS:

o Determine if RCS subcooling based on core exit TCs is greater than (R.08) °F [(R.09) °F for adverse containment]

o Depressurize RCS using normal PRZR spray o Determine if normal PRZR spray is not available o Depressurize RCS using one PRZR PORV o Determine if RCS cannot be depressurized using any PRZR PORV o Depressurize RCS using auxiliary spray o Determine if RCS subcooling based on core exit TCs is between (R.01) °F [(R.02) °F for

adverse containment] and (R.08) °F [(R.09) °F for adverse containment] o Determine if PRZR level is greater than (D.08) °F [(D.09) °F for adverse containment] o Determine if RCS subcooling based on core exit TCs is less than (R.01) °F [(R.02) °F for

adverse containment] o Increase RCS makeup flow as necessary o Stop RCS depressurization

INSTRUMENTATION:

o PRZR level indication o RCS pressure indication o Core exit TCs temperature indication o Normal PRZR spray valve position indication o Auxiliary spray valve position indication

CONTROL/EQUIPMENT:

o Normal PRZR spray valve controls o PRZR PORVs and block valves control o Auxiliary spray valve controls

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KNOWLEDGE:

o RCS depressurization should be stopped when RCS subcooling based on core exit TCs is between (R.01) °F [(R.02) °F for adverse containment] and (R.08) °F [(R.09) °F for adverse containment].

o It is possible that this pressure reduction could result in loss of the normal conditions for RCP operation, i.e., minimum number one seal different ial pressure or minimum number one seal leakoff flow. If either condition is lost, the affected RCP should be stopped. This action is not specifically included in this step, but is inferred by the pressure reduction.

o If subcooling decreases below the setpoint for increasing RCS makeup during the depressurization, the operator should take the appropriate actions such as closing the PORV or the block valve for a stuck open PORV, and wait to see if the actions are successful (i.e., allow adequate time for va lves to stroke closed), before increasing RCS makeup flow as necessary to restore subcooling. If the actions stop the depressurization and subcooling is restored, increasing RCS makeup flow is not necessary.


o (R.01) The sum of temperature and pressure measurement system errors, including allowances for normal channel accuracies, translated into temperature using saturation tables.

o (R.02) The sum of temperature and pressure measurement system errors, including allowances for normal channel accuracies and post accident transmitter errors, translated into temperature using saturation tables.



o (D.08) PRZR level at the upper tap, including allowances for normal channel accuracy, minus 20% for operating margin.

o (D.09) PRZR level at the upper tap, including allowances for normal channel accuracy, post accident transmitter errors, and reference leg process errors, minus 20% for operating margin, not less than 50%

03/23/2004



STEP: Check If RHR System Should Be Placed In Service

PURPOSE: To check for required conditions and then place RHR System in service, if appropriate

BASIS:

The RHR System is designed to operate below specific RCS pressure and temperature conditions. If these conditions are not met, previous actions to establish conditions were not complete, this step directs the operator to continue with subsequent return to those steps for completion of the actions until the conditions are rechecked later in this guideline. The plant engineering staff is consulted to determine if the RHR System should be placed in service according to plant specific procedures when required conditions are established. At this time the plant engineering staff should determine RHR System availability. RHR System availability includes confirmation of equipment needed for RHR System operation (RHR suction valves, RHR pumps, etc.) and confirmation of adequate liquid inventory in the RCS to preclude steam from entering the RHR pump suction.

ACTIONS:

o Determine if RCS temperature is less than (F.06) °F [(F.07) °F for adverse containment] o Determine if RCS pressure is less than (B.01) psig [(B.02) psig for adverse containment] o Consult plant engineering staff to determine if RHR System should be placed in service

INSTRUMENTATION:

o RCS temperature indication o RCS pressure indication o Plant specific RHR System instrumentation including va lve position and pump status

indication o RVLIS indication

CONTROL/EQUIPMENT:

Plant specific RHR System controls for valves and pumps

KNOWLEDGE:

Understanding of RVLIS function, configuration and interpretation

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o (F.06) Temperature requirement, including allowances for normal channel accuracy, for placing RHR system in service.

o (F.07) Temperature requirement, including allowances for normal channel accuracy and post accident transmitter errors, for placing RHR system in service.

o (B.01) Pressure requirement, including allowances for normal channel accuracy, for placing RHR system in service.

o (B.02) Pressure requirement, including allowances for normal channel accuracy and post accident transmitter errors, for placing RHR system in service.

o Procedure for placing RHR System in service o Plant personnel comprising the "plant engineering staff"

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STEP: Check If SI Accumulators Should Be Isolated

PURPOSE: To prevent accumulator nitrogen from being injected into the RCS

BASIS:

Accumulators are isolated or vented after their liquid contents are discharged into the RCS. Isolating or venting accumulators prevents nitrogen injection into the RCS. Nitrogen could collect in high places and render PRZR pressure control ineffective or cause gas binding in the SG U-tubes. Venting the nitrogen gas also prevents nitrogen injection. The hot leg temperature of (F.05) °F should be determined so that the RCS saturation pressure exceeds the accumulator pressure after the accumulator water has been discharged. This precludes nitrogen injection into the RCS. To determine the hot leg temperature, an ideal gas expansion calculation should be performed based on nominal plant specific values for initial accumulator tank pressure (P1), initial nitrogen gas volume (V1), and final nitrogen gas volume (V2). The final nitrogen gas volume should be equivalent to the total accumulator tank volume. The RCS pressure at empty tank conditions (P2) is determined from:

P1V1γ = P2V2

γ where γ = 1.25 for ideal gas expansion. The setpoint temperature of (F.05) °F is the saturation temperature corresponding to P2. Instrument uncertainties are not included in the determination of the RCS hot leg temperature setpoint to preclude a bias toward either having more accumulator water injected into the RCS or having less nitrogen injected into the RCS. If it is determined that any SI accumulator cannot be isolated or vented, the plant engineering staff should be consulted to evaluate the effect of nitrogen in the RCS on plant recovery actions. Nitrogen in the RCS may interfere with core cooling by natural circulation, if required, following a small-break LOCA. The plant engineering staff will evaluate whether actions should be taken to prevent or minimize nitrogen injection, or vent the nitrogen from the RCS following injection.

ACTIONS:

o Determine if at least two RCS hot leg temperatures are less than (F.05) °F o Determine if power is available to isolation valves o Restore power to accumulators isolation valves o Close all SI accumulator isolation valves o Vent any unisolated accumulators o Determine if an SI accumulator cannot be isolated or vented o Consult plant engineering staff

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INSTRUMENTATION:

o RCS hot leg temperatures indication o Accumulator isolation valve position indication o Accumulator isolation valve power supply indication o Accumulator vent valve position indication

CONTROL/EQUIPMENT:

o Accumulator isolation valve switches o Accumulator isolation valve power supply controls o Accumulator vent valve switches

KNOWLEDGE:

Approximate time required to vent accumulators. RCS depressurization can be performed concurrently with accumulator venting provided RCS pressure is maintained greater than the accumulator nitrogen pressure.


o Plants that have qualified RCS wide range pressure transmitters may use RCS pressure instead of RCS hot leg temperature to determine when the accumulators should be isola ted.

o Plants that have qualified pressure transmitters on the accumulators may use accumulator pressure instead of RCS hot leg temperature to determine when the accumulators should be isolated.

o (F.05) RCS hot leg temperature to prevent accumulator nitrogen injection. Refer to Background Document for guideline ECA-1.1.


03/23/2004



STEP: Check if RCPs Must Be Stopped

PURPOSE: To stop RCPs if minimum operating conditions cannot be maintained for the Number 1 seal

BASIS:

It is very unlikely that the RCPs will be running when entering guideline SBCRG. However, if the RCPs are running, this step provides criteria to stop the pumps. Because of the designed operational characteristics of the RCP Number 1 seal, preventing seal damage requires a certain minimum delta-P and leakoff flow. This step provides a check on those minimum conditions

ACTIONS:

o Determine if Number 1 seal differential pressure is less than (W.01) psig o Determine if Number 1 seal leakoff flow is less than (W.02) gpm o Stop affected RCP(s)

INSTRUMENTATION:

o RCP Number 1 seal delta-P indication o RCP Number 1 seal leakoff flow indication

CONTROL/EQUIPMENT:

RCP switches

KNOWLEDGE:



o (W.01) Minimum seal differential pressure for continued RCP operation, including allowances for normal channel accuracy

o (W.02) Minimum seal leakoff flow for continued RCP operation, including allowances for normal channel accuracy

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STEP: Check RCS Temperature – GREATER THAN 200 °F

PURPOSE: To check if cold shutdown conditions have been achieved

BASIS:

This guideline provides generic instruction for cooldown and depressurization of the plant to cold shutdown conditions of less then 200 °F. Subsequent actions necessary for repair are plant- and event-specific.

ACTIONS:

Check RCS temperature

INSTRUMENTATION:

RCS temperature indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


N/A

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STEP: Try To Add Makeup To RCS From Alternate Source

PURPOSE: To provide a source of makeup to the RCS

BASIS:

At this point in guideline SBCRG, no verifiable SI flow is being delivered to the RCS. If operators have been unable to establish verifiable SI flow to the RCS in Step 14, there may be no makeup flow to the RCS. Under these conditions, decay heat generated in the core will convert the liquid into steam, which then exits the break in the RCS. Therefore, the operator should provide makeup to the RCS from any alternate source. The identity of alternate sources is a plant-specific characteristic. A typical alternate source of makeup would be providing fluid from the Reactor Makeup Water Control System using the centrifugal charging pumps and the normal charging line.

ACTIONS:

Try to add makeup to RCS from alternate source

INSTRUMENTATION:

Plant-specific instrumentation associated with alternate makeup source

CONTROL/EQUIPMENT:

Plant specific controls associated with alternate makeup source

KNOWLEDGE:

Plant specific design requirements may limit makeup to only one system (RWST or RCS) at a time. If there is conflict between these two priorities when this step is encountered, then makeup to the RWST should be terminated and the operator should concentrate on aligning makeup to the RCS as quickly as possible to provide core cooling.


Alternate source for adding makeup to RCS

03/23/2004



STEP: Check If Cooldown Rate Is Adequate

PURPOSE: To determine if the restricted cooldown rate is adequate to maintain core cooling

BASIS:

In previous steps of this guideline, operators initiated a controlled cooldown of the RCS with a restricted cooldown rate. This cooldown allows depressurization of the RCS, which, in turns reduces break flow and required makeup flow to the RCS. If the cooldown rate allows the operator to maintain nominal core cooling conditions (as indicated by adequate reactor coolant inventory and stable or decreasing core exit TC temperatures), then the operator continues in a loop until core temperatures decrease below 200 °F. If, however, reactor coolant inventory is not adequate or if core exit TC temperatures are increasing, then the guideline instructs the operator to perform a more rapid cooldown of the RCS.

ACTIONS:

o Determine if RVLIS indication is greater than (K.02) or (L.08), as applicable. o Determine if RCS subcooling (based on core exit TCs) is greater than (R.12) °F [(R.13) °F

for adverse containment]

INSTRUMENTATION:

o RVLIS indication o Core exit TCs temperature indication

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

o Understanding of RVLIS function, configuration, and interpretation o Due to the less restrictive SI termination and reinitiation criteria provided in this guideline

the operator should be especially alert for any decrease in RCS subcooling or vessel level that warrants SI reinitiation

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o If RVLIS is not available, RCS subcooling based on core exit TCs is sufficient for terminating SI since the guideline adds a 50 °F margin to instrument uncertainties. This 50°F margin allows sufficient time for operator action to reinitiate SI before core uncovery.


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STEP: Check If All Intact SGs Should Be Depressurized To (O.06) PSIG

PURPOSE: To depressurize the RCS to 25 psi above the accumulator high pressure setpoint

BASIS:

Since the RCS will be saturated at this time, RCS pressure is approximately the same as SG pressure. In this step SG pressures (and thus RCS pressure) are decreased at the maximum rate to 25 psi above the accumulator high pressure alarm setpoint. SG pressure is used due to its accuracy; i.e., the RCS pressure instrument may have high inaccuracies since it is located inside containment. The value of 25 psi is arbitrarily selected as a pressure that is slightly above the accumulator high pressure alarm setpoint. If the condenser and PORVs are not available, the step instructs the operator to use any plant specific means of removing water or steam from the SGs. This could include opening the blowdown lines or operating the steam driven AFW pump. If the SG pressures are less than (O.06) psig, the step instructs the operator to skip to Step 37 to inject the accumulators as necessary.

ACTIONS:

o Determine if SG pressures are less than (O.06) psig o Dump steam to condenser at maximum rate from all intact SGs o Manually or locally dump steam at maximum rate from all intact SGs using SG PORVs or

other plant specific means o Stop SG depressurization

INSTRUMENTATION:

o Steam dump valves to condenser position indication o SG PORVs position indication o Plant specific instrumentation to indicate dumping steam by other means o SG pressure indication

CONTROL/EQUIPMENT:


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KNOWLEDGE:

N/A


o (O.06) Value 25 psi above the accumulator high pressure alarm setpoint. See basis section for explanation of 25 psi.

o Other means of dumping steam

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STEP: Depressurize All Intact SGs To Inject Accumulators As Necessary

PURPOSE: To inject the accumulators into the RCS by reducing pressure

BASIS:

As mentioned in the previous step, the RCS will be saturated at this time and, therefo re, RCS pressure is approximately equal to SG pressure. In this step the intact SGs are depressurized (and thus the RCS) to inject the accumulators. SG depressurization is used here due to its accuracy; i.e., the RCS pressure instrument may have high inaccuracies since it is located inside containment. Operators dump steam as necessary to maintain RVLIS full range indication at the top of the core from the accumulator water injection. In other words, the SGs are depressurized relatively slowly such that the accumulator water injection is minimized, extending the time to depletion of the accumulators. When SG pressures decrease to less than (O.07) psig, the accumulator contents will have been injected into the RCS and the operators stop SG depressurization. This step sets a SG pressure limit to preclude significant nitrogen injection into the RCS. To determine the SG pressure limit, perform an ideal gas expansion calculation based on nominal plant specific values for initial accumulator tank pressure (P1), initial nitrogen gas volume (V1), and final nitrogen gas volume (V2). The final nitrogen gas volume should be equivalent to the total accumulator tank volume. The RCS pressure at empty tank conditions (P2) is determined from:

P1V1γ = P2V2

γ where γ = 1.25 for ideal gas expansion. Subtracting the RCS to SG delta-P from P2 determines the SG pressure limit. Calculate the RCS to SG delta-P as described in the RCP TRIP/RESTART section in the Generic Issues of the Executive Volume. The SG pressure limit does not include instrument uncertainties to preclude a bias toward either having more accumulator water injected into the RCS or having less nitrogen injected into the RCS. If the condenser and PORVs are not available, the operator is instructed to use any plant specific means of removing water or steam from the SGs. This could include opening the blowdown lines or operating the steam driven AFW pump.

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ACTIONS:

o Determine if SG pressures are less than (O.07) psig o Dump steam to condenser from all intact SGs as necessary to maintain RVLIS full range

indication at (K.02) – IF NO RCPs RUNNING o Dump steam to condenser from all intact SGs as necessary to maintain RVLIS dynamic head

indication at (L.08) – IF ONE RCP RUNNING o Manually or locally dump steam from all intact SGs as necessary to maintain RVLIS full

range indication at (K.02) using SG PORVs or other plant specific means o Stop SG depressurization

INSTRUMENTATION:

o RVLIS indication o SG pressure indication o Steam dump valves to condenser position indication o SG PORVs position indication o Plant specific instrumentation to indicate dumping steam by other means

CONTROL/EQUIPMENT:


KNOWLEDGE:

Controlling SG depressurization such that accumulator injection is minimized

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o (O.07) Minimum SG pressure which prevents injection of accumulator nitrogen into the RCS. Refer to background document for guideline ECA-1.1.


o (L.08) RVLIS dynamic range value corresponding to an average system void fraction of 25 percent with 1 RCP running, including allowances for instrument uncertainties.

o If the specific plant does not have a RVLIS, then core exit TCs could be used in lieu of RVLIS as an indication that SG depressurization and, therefore, accumulator injection is occurring properly

o Other means of dumping steam o As long as the RVLIS dynamic range uncertainty for the Westinghouse RVLIS design is less

than +/-6%, the uncertainty does not need to be included in the calculation of the plant-specific EOP setpoints.

03/23/2004



STEP: Check If SI Accumulators Should Be Isolated

PURPOSE: To prevent accumulator nitrogen from being injected into the RCS

BASIS:

Operators isolate the accumulators are isolated or vented after the accumulator liquid contents are discharged into the RCS. Isolating or venting accumulators prevents nitrogen injection into the RCS. Nitrogen could collect in high places and render PRZR pressure control ineffective or cause gas binding in the SG U-tubes. Venting the nitrogen gas also prevents nitrogen injection. The hot leg temperature of (F.05) °F should be determined so that the RCS saturation pressure exceeds the accumulator pressure after the accumulator water has been discharged. This precludes nitrogen injection into the RCS. To determine the hot leg temperature, perform an ideal gas expansion calculation based on nominal plant specific values for initial accumulator tank pressure (P1), initial nitrogen gas volume (V1), and final nitrogen gas volume (V2). The final nitrogen gas volume should be equivalent to the total accumulator tank volume. The RCS pressure at empty tank conditions (P2) is determined from:

P1V1γ = P2V2

γ where γ = 1.25 for ideal gas expansion. The setpoint temperature of (F.05) °F is the saturation temperature corresponding to P2. The determination of the RCS hot leg temperature setpoint does not include instrument uncertainties to preclude a bias toward either having more accumulator water injected into the RCS or having less nitrogen injected into the RCS. If it is determined that any SI accumulator cannot be isolated or vented, the plant engineering staff should be consulted to evaluate the effect of nitrogen in the RCS on plant recovery actions. Nitrogen in the RCS may interfere with core cooling by natural circulation, if required, following a small-break LOCA. The plant engineering staff will evaluate whether actions should be taken to prevent or minimize nitrogen injection, or vent the nitrogen from the RCS following injection.

ACTIONS:

o Determine if at least two RCS hot leg temperatures are less than (F.05) °F o Determine if power is available to the accumulator isolation valves o Restore power to accumulator isolation valves o Close all SI accumulator isolation valves o Vent any unisolated accumulators o Determine if an SI accumulator cannot be isolated or vented o Consult plant engineering staff

03/23/2004



INSTRUMENTATION:

o RCS hot leg temperature indication o Accumulator isolation valve position indication o Accumulator isolation valve power supply indication o Accumulator vent valve position indication

CONTROL/EQUIPMENT:

o Accumulator isolation valve switches o Accumulator isolation valve power supply controls o Accumulator vent valve switches

KNOWLEDGE:

Approximate time required to vent accumulators. RCS depressurization can be performed concurrently with accumulator venting provided RCS pressure is maintained greater than the accumulator nitrogen pressure.


o Plants that have qualified RCS wide-range pressure transmitters may use RCS pressure instead of RCS hot leg temperature to determine when the accumulators should be isolated.

o Plants that have qualified pressure transmitters on the accumulators may use accumulator pressure instead of RCS hot leg temperature to determine when the accumulator should be isolated.

o (F.05) RCS hot leg temperature to prevent accumulator nitrogen injection. Refer to Background Document for guideline ECA-1.1.


03/23/2004



STEP: Check If RCPs Must Be Stopped

PURPOSE: To stop RCPs if minimum operating conditions cannot be maintained for the Number 1 seal

BASIS:

It is very unlikely that the RCPs will be running when entering guideline SBCRG. However, if the RCPs are running, this step provides criteria to stop the pumps. Because of the designed operational characteristics of the RCP Number 1 seal, preventing seal damage requires a certain minimum delta-P and leakoff flow. This step provides a check on those minimum conditions

ACTIONS:

o Determine if Number 1 seal differential pressure is less than (W.01) psig o Determine if Number 1 seal leakoff flow is less than (W.02) gpm o Stop affected RCP(s)

INSTRUMENTATION:

o RCP Number 1 seal delta-P indication o RCP Number 1 seal leakoff flow indication

CONTROL/EQUIPMENT:

RCP switches

KNOWLEDGE:



o (W.01) Minimum seal differential pressure for continued RCP operation, including allowances for normal channel accuracy

o (W.02) Minimum seal leakoff flow for continued RCP operation, including allowances for normal channel accuracy

03/23/2004



STEP: Depressurize All Intact SGs To Atmospheric Pressure

PURPOSE: To depressur ize the SGs (and, therefore, the RCS) to atmospheric pressure

BASIS:

Decreasing steam generator pressure also decreases the RCS temperature and pressure. The purpose of the depressurization in this step is twofold. First, reduce RCS pressure and temperature to RHR System conditions. Second, reduce steam generator pressures (and thus RCS pressure) to atmospheric pressure to reduce break flow. At this time in the guideline, there is no SI flow to the RCS. If the LOCA is a stuck open PORV (i.e., break is at a high RCS elevation), depressurizing the RCS to atmospheric pressure increases the time to uncover the core by many hours. Even for lower elevation RCS breaks (e.g., cold leg break), depressurizing the RCS to atmospheric pressure increases the time to core uncovery.

ACTIONS:

o Depressurize all intact SGs to atmospheric pressure o Maintain cooldown rate in RCS cold legs less than 100 °F/hr o Dump steam to the condenser from all intact SGs o Manually or locally dump steam from all intact SGs using SG PORVs or other plant specific

means

INSTRUMENTATION:

o RCS cold leg temperature indication o Steam dump valves to condenser position indication o SG PORVs position indication o Plant specific instrumentation to indicate dumping steam by other means

CONTROL/EQUIPMENT:


KNOWLEDGE:

To minimize offsite releases, maximize the cooldown rate to cool down as quickly as possible without exceeding 100 °F/HR. Possible upper head void formation due to cooling down at this rapid rate is not a concern in this guideline since a loss of coolant accident already exists.

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03/23/2004



STEP: Check Core Exit TCs – LESS THAN 1200F °

PURPOSE: To determine if severe conditions exist that require a transition to the SAMGs

BASIS:

The control room operators enter Severe Accident Management Guidelines (SAMGs) from the SBCRG when core damage occurs. The SBCRG to SAMG transition uses, as part of the transition criteria, a core exit thermocouple temperature indication greater than 1200 °F to indicate the need to transition from the SBCRG to the SAMGs. The 1200 °F criterion for transition from the SBCRG to the SAMGs is identical to the 1200 °F criteria used in the Emergency Response Guidelines. If the operator enters this step and core exit TC temperatures are greater than 1200 °F and increasing, the operator should trans ition to the SAMGs. This condition indicates that all attempts to restore core cooling have failed, core damage can not be prevented, and the operator should go to the SAMGs. If the operator enters this step and core exit TC temperatures are less than 1200 °F or core exit TC temperatures are greater than 1200 °F and decreasing, the operator will stay in the loop between Steps 40 and 42 in guideline SBCRG. In this loop, the operator performs steps, as appropriate, until conditions are met to place the RHR System in service or core exit thermocouple temperatures meet the conditions to transition to the SAMGs.

ACTIONS:

o Determine if core exit TCs are less than 1200 °F o Determine if core exit TCs are greater than 1200 °F o Determine if core exit TCs are increasing o Transfer to SACRG-1, SEVERE ACCIDENT CONTROL ROOM GUIDELINE INITIAL

RESPONSE, Step 1

INSTRUMENTATION:

Core exit TC temperature indication

CONTROL/EQUIPMENT:

N/A

03/23/2004



KNOWLEDGE:

N/A


N/A

03/23/2004



STEP: Check If RHR System Should Be Placed In Service

PURPOSE: To check for required conditions and then place RHR System in service, if appropriate

BASIS:

The RHR System is designed to operate below specific RCS pressure and temperature conditions. If previous actions to establish conditions were not complete, this step directs the operator to return to those steps for completion of the actions. The operators consult the plant engineering staff to determine if the RHR System should be placed in service according to plant specific procedures when required conditions are established. At this time, the plant engineering staff should determine RHR System availability. RHR System availability includes confirmation of equipment needed for RHR System operation (RHR suction valves, RHR pumps, etc.) and confirmation of adequate liquid inventory in the RCS to preclude steam from entering the RHR pump suction.

ACTIONS:

o Determine if RCS temperature is less than (F.06) °F [(F.07) °F for adverse containment] o Determine if RCS pressure is less than (B.01) psig [(B.02)psig for adverse containment] o Consult plant engineering staff to determine if RHR System should be placed in service

INSTRUMENTATION:

o RCS temperature indication o RCS pressure indication o Plant-specific RHR System instrumentation including valve position and pump status

indication o RVLIS indication

CONTROL/EQUIPMENT:

Plant-specific RHR System controls for valves and pumps

KNOWLEDGE:

Understanding of RVLIS function, configuration, and interpretation

03/23/2004




o (F.06) Temperature requirement, including allowances for normal channel accuracy, for placing RHR system in service.

o (F.07) Temperature requirement, including allowances for normal channel accuracy and post accident transmitter errors, for placing RHR system in service.

o (B.01) Pressure requirement, including allowances for normal channel accuracy, for placing RHR system in service.

o (B.02) Pressure requirement, including allowances for normal channel accuracy, and post accident transmitter errors, for placing RHR system in service.

o Procedure for placing RHR System in service o Plant personnel comprising the “plant engineering staff”

03/23/2004



STEP: Maintain RCS Heat Removal

PURPOSE: To ensure RCS heat removal

BASIS:

This step instructs the operator to maintain RCS heat removal either by continued RHR System operation (if available) or by dumping steam, since at this time the ECCS may be unable to provide makeup flow to the RCS. If no intact SGs are available for dumping steam and the RHR System is not in service, the guideline instructs the operator to use a faulted SG to maintain RCS heat removal.

ACTIONS:

o Determine if no intact SG is available and RHR System is not in service o Maintain RCS heat removal using RHR System if in service o Dump steam to condenser from intact SGs o Manually or locally dump steam from intact SGs using SG PORVs or other plant-specific

means o Dump steam from faulted SG

INSTRUMENTATION:

o RCS temperature indication o Plant-specific RHR System instrumentation including valve position and pump status

indication o Steam dump valves to condenser position indications o SG PORVs position indication o Plant-specific instrumentation to indicate dumping steam by other means

CONTROL/EQUIPMENT:

o Steam dump valves to condenser switches o SG PORVs switches o Plant-specific RHR System controls for valves and pumps o Plant-specific controls to dump steam by other means

03/23/2004



KNOWLEDGE:

If the RCS is not full of liquid at this time, it is especially important to keep the secondary system adequately full of water to promote reflux cooling. Reflux cooling is the mechanism by which steam generated in the RCS enters the SG tubes and is condensed by the cold water on the SG secondary side. This liquid then remains in the primary system and promotes cooling.



03/23/2004



STEP: Check Containment Hydrogen Concentration

PURPOSE: To check if an excessive containment hydrogen concentration is present

BASIS:

This step instructs the operator to obtain a current hydrogen concentration measurement. Depending upon the magnitude of the hydrogen concentration, the operator will either continue with guideline SBCRG, turn on the hydrogen recombiners or notify the plant engineering staff to determine additional recovery actions before continuing with the guideline. When inadequate core cooling has occurred, the containment hydrogen concentration may be as much as 10 to 12 volume percent, depending on the amount of metal-water reaction (to produce hydrogen) that has occurred in the core. The hydrogen concentration is of concern since a flammable mixture can burn, if an ignition source is available, and cause a sudden rise in containment pressure which may challenge containment integrity. The step instructs the operator to obtain a current measurement of containment hydrogen concentration to ascertain the potential flammability of the combustible gases in the containment. Note that to have the potential for flammable hydrogen concentrations, an inadequate core cooling situation must have already existed. Without an inadequate core cooling situation, sufficient hydrogen would not be expected to have been produced to cause potentially flammable mixtures. The operator determines the flammability of the hydrogen mixture with respect to the possible containment pressure rise. If the hydrogen mixture is between 0.5 volume percent and 6.0 volume percent in dry air; either no hydrogen burn is possible or a limited burn may occur which does not produce a significant pressure rise. A hydrogen concentration not to exceed 6.0 volume percent in dry air corresponds to the upper limit of operability for the hydrogen recombiner, represented by the footnote (T.05). If containment hydrogen concentration is between 0.5 volume percent and (T.05), In this case the operator starts the hydrogen recombiner system to reduce slowly the containment hydrogen concentration. If the hydrogen concentration is less than 0.5 volume percent in dry air, a flammable situation is not imminent and the operator continues with guideline SBCRG. If the concentration is greater than (T.05) volume percent in dry air, the operator immediately notifies the plant engineering staff of the situation. In this case, the operator consults the plant engineering staff for additional recovery actions while proceeding with this guideline. This guideline step references all hydrogen measurements to concentrations in dry air even though the actual containment environment may contain significant steam concentrations. The reason for this is twofold: 1) most hydrogen measurement systems remove moisture from the sample thus approximating a dry air condition and 2) the indication of the potential of hydrogen flammability is conservative when based upon using hydrogen concentration in dry air.

03/23/2004



ACTIONS:

o Obtain a hydrogen concentration measurement o Determine if hydrogen concentration is less than (T.05)% in dry air o Determine if hydrogen concentration is less than 0.5% in dry air o Consult plant engineering staff for additional recovery actions o Turn on hydrogen recombiner system

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

o Plant specific controls/equipment to obtain a hydrogen concentration measurement o Hydrogen recombiner system controls

KNOWLEDGE:

N/A


o Method of obtaining hydrogen concentration measurement inside containment o (T.05) Containment hydrogen concentration corresponding to the limit of operability of the

hydrogen recombiners, not to exceed 6% o Plant personnel comprising the “plant engineering staff”

03/23/2004



STEP: Consult Plant Engineering Staff

PURPOSE: To consult with the plant engineering staff for further actions

BASIS:

This guideline provides generic instructions for cooldown and depressurization of the plant to atmospheric conditions following a loss of emergency coolant recirculation caused by containment sump blockage. Subsequent actions are plant-specific. Plant operators, engineering staff and utility management need to make decisions about long-term plant operation and any repairs necessary for plant restart. Some LOCAs will occur that do not generate the Hi-3 signal needed to initiate containment spray. The presence of acidic water from the LOCA may lead to chloride- induced stress corrosion of the recirculation loop piping. If spray was not initiated during E-1, LOSS OF REACTOR OR SECONDARY COOLANT, the operator should evaluate plant conditions to determine if sodium hydroxide addition should be added. If required, the operator should take appropriate actions to add sodium hydroxide to increase the sump pH.

ACTIONS:

Consult plant engineering staff

INSTRUMENTATION:

N/A

CONTROL/EQUIPMENT:

N/A

KNOWLEDGE:

N/A


Plant personnel comprising the “plant engineering staff’

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4.2 Step Sequence Requirements This section consists of a table that presents the existing guideline sequence and identifies the allowed interchangeability of guideline steps for the benefit of the utility EOP writer. The Step Sequence Table for SBCRG is provided on the following pages. The interchangeability of guideline steps is identified by the numbers in the column to the right of each guideline step. Refer to the Users Guide in the Executive Volume for information on use of the step sequence tables.

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STEP SEQUENCE FOR SBCRG, PAGE 1

STEP SEQUENCE 1 Monitor Low-Head SI Pump Suction Conditions – NO INDICATION OF

CAVITATION 1

2 Verify Containment Fan Coolers – RUNNING IN EMERGENCY MODE 1 3 Stop Containment Spray Pumps 2 4 Monitor RWST Level – GREATER THAN (U.03) 2 5 Try To Establish SI Recirculation Suction 3 6 Try To Establish Low-Head SI Recirculation Flow 4 7 Try To Establish High-Head SI In Recirculation Mode 5 8 Try To Establish High-Head SI With Suction From RWST 6 9 Consult Plant Engineering Staff To Determine Optimum SI And Spray

Alignment 7

10 Verify No Backflow From RWST To Sump 7 11 Add Makeup To RWST As Necessary 7 12 Monitor For Adequate RCS Makeup Flow 8 13 Operate ECCS To Maintain RCS Makeup Flow Without Pump Cavitation 8 14 Monitor For RCS Makeup Capability 9 15 Check RCS Pressure: GREATER THAN (B.07) PSIG [(B.08) PSIG FOR

ADVERSE CONTAINMENT] 10

16 Check Intact SG Levels 11 17 Initiate RCS Cooldown To Cold Shutdown 11 18 Check If An RCP Should Be Started 12 19 Check If SI Is In Service 13 20 Check If SI Can Be Terminated 14 21 Reset Containment Isolation Phase A And Phase B 15 22 Establish Instrument Air To Containment 16 23 Stop SI Pumps And Place In Standby 17 24 Isolate BIT 18a 25 Establish Charging Flow 18b 26 Check If Charging/SI Pump Should Be Realigned To RWST 19 27 Check If Running Low-Head SI Pump Should Be Stopped 20

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STEP SEQUENCE FOR SBCRG, PAGE 2

STEP SEQUENCE 28 Monitor For Adequate RCS Makeup Flow 21 29 Depressurize RCS To Decrease RCS Subcooling 22 30 Check If RHR System Should Be Placed In Service 23 31 Check If SI Accumulators Should Be Isolated 23 32 Check If RCPs Must Be Stopped 23 33 Check RCS Temperature – GREATER THAN 200 °F 24 34 Try To Add Makeup To RCS From Alternate Source 25 35 Check If Cooldown Rate Is Adequate 26 36 Check If All Intact SGs Should Be Depressurized To (O.06) PSIG 27 37 Depressurize All Intact SGs To Inject Accumulators As Necessary 28 38 Check If SI Accumulators Should Be Isolated 29 39 Check If RCPs Must Be Stopped 29 40 Depressurize All Intact SGs To Atmospheric Pressure 30 41 Check Core Exit TCs – LESS THAN 1200 °F 31 42 Check If RHR System Should Be Placed In Service 32 43 Maintain RCS Heat Removal 33 44 Check Containment Hydrogen Concentration 34 45 Consult Plant Engineering Staff 35

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5. FREQUENT QUESTIONS The following questions have been frequently asked about SBCRG, SUMP BLOCKAGE CONTROL ROOM GUIDELINE: Q. Should this Control Room Guideline be included in the Severe Accident Management

Guidelines (SAMGs) with the existing SACRG-1 and SACRG-2? A. No, the SBCRG must remain separate from the SAMGs. The SAMGs address

contingency responses to conditions in which core damage has occurred, is occurring, or can not be prevented. The primary objective of the SBCRG is to prevent core damage. The entry conditions, priorities and strategies of the SBCRG are not consistent with those of the SAMGs.

Q. If we have previously implemented procedure changes to address recirculation sump

blockage issues, does issuance of this guideline require us to remove these changes and implement changes in accordance with SBCRG?

A. No, the Sump Blockage Control Room Guideline was prepared to provide guidance to

individual plants and is not intended to be prescriptive in nature. On a plant-specific basis, if you determine that existing procedures best address the concerns of sump blockage, there is no requirement to make additional changes.

Q. The entry conditions described for the SBCRG require use of non-qualified

instrumentation and operator interpretation. What is the justification for the risk of possible operator error, leading to improper creation of beyond-design-basis conditions?

A. The purpose of the SBCRG is to provide guidance in the event of beyond-design-basis

sump blockage. The potential consequences of this condition are severe. Unfortunately, for most plants, no instrumentation exists that provides explicit, unambiguous, and qualified indication of sump blockage. Therefore, a plant-specific evaluation should be performed to determine the relative benefit (risk reduction) associated with providing guidance based on the SBCRG compared to the additional risk associated with incorrect operator response. The consensus of the Procedures Working Group is that such guidance is risk beneficial. If, however, plant specific evaluation determines that the risk of improper action using SBCRG guidance exceeds the benefit of providing such guidance, this evaluation provides justification for not implementing procedure changes.

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Q. Some of the compensatory measures included in the SBCRG are inconsistent with the accident analyses and/or licensing basis of the plant. How should this inconsistency be resolved?

A. The Revised NRC Staff Responses to Industry Questions #40. #58, and #61 Regarding

Bulletin 2003-01 provides the following information: “Responsive compensatory measures are action taken to reduce the risk of sump failure or its consequences (e.g., loss of core cooling and/or loss of containment cooling) during the recirculation phase of an accident following indications of degraded sump performance and/or impending sump failure. As sump failure is not considered in plants’ current licensing bases, it may be warranted for licensees to take appropriate actions in response to indications of likely sump failure, even if the actions are not analyzed in the current licensing basis.” “The implementation of responsive measures may involve revisions to emergency procedures or guidelines, but it is not necessary to revise the Final Safety Analysis Report to include responsive measures for beyond-design-basis occurrences such as sump failure. Although licensees should evaluate any changes for risk benefit, this type of action would not typically require prior NRC approval.”

Q. The INTRODUCTION to this Background Document states that individual plants may

decide to incorporate this guideline into the existing Emergency Procedures. If this is done, how should conflicts between this guideline and existing procedures, such as FR-C.1 and FR-Z.1, be resolved?

A. The exact method of resolving such conflicts depends on the method chosen to implement

the SBCRG guidance. If the guidance becomes a new procedure (e.g., ECA-1.3, LOSS OF EMERGENCY COOLANT RECIRCULATION CAUSED BY SUMP BLOCKAGE), then the new procedure should have a higher priority, similar to that of ECA-0.0, LOSS OF ALL AC POWER. If the guidance is incorporated into an existing procedure, such as ECA-1.1, LOSS OF EMERGENCY COOLANT RECIRCULATION, then conflicting procedures might include instructions to the operators that SI and spray pumps are to be operated in accordance with the new guidance. This would be similar to the existing CAUTION in FR-Z.1, RESPONSE TO HIGH CONTAINMENT PRESSURE, stating, “If ECA-1.1, LOSS OF EMERGENCY COOLANT RECIRCULATION, is in effect, containment spray should be operated as directed in ECA-1.1 rather than step 3 below.”

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Q. In Step 5, if both low-head SI pumps have previously been tripped because of symptoms of loss of suction, should the operator attempt to restart a pump in the RNO a.2) or 3)?

A. Yes, actions taken by the operator or natural phenomena (such as debris dropping from the

sump screen when all recirculation flow stops) may have improved pump suction conditions such that a pump may now run successfully with suction from the sump. If conditions have not improved, an attempt to start a pump followed by tripping the pump has little effect on making overall plant conditions worse. Overall, the potential benefits gained if a low-head SI pump does successfully start and run outweigh the potential negative impacts associated with further pump damage.

Q. The sequence of Steps 5 through 9 may establish a condition in which a low-head SI pump

is running with suction from the sump and aligned to discharge to the RCS and at the same time a high-head SI pump or charging/SI pump is running with suction from the RWST and delivering flow to the RCS. For some RCS pressures, the low-head SI pump may then be delivering flow to the RCS, but with the flow less than the minimum observable value. Is it the intent of this sequence to have two pumps both delivering flow to the RCS from separate sources, or should one of the pumps be stopped? If one of the pumps should be stopped, which one?

A. The key to answering this question is that, although the low-head SI pump may be

delivering flow to the RCS, if the flow is less than the minimum observable value, the operators have no verification of this flow. Therefore, the observed flow from a high-head pump is necessary to ensure makeup flow to the RCS. If the low-head SI pump actually is delivering flow, this just improves the core cooling conditions without any significant negative impact.

Q. The step providing transition to SACRG-1 seems to be buried near the end of the

procedure. Since recirculation sump blockage presents a significant challenge to core cooling, core temperatures likely will exceed 1200 °. At this location, operators might not perform the transfer in a timely manner. Should the transition step be located closer to the start of the guideline?

A. The operators should not abandon approved procedures and transition to Severe Accident

Management Guidance until all efforts to restore an acceptable level of core cooling have been exhausted. Preceding steps provide guidance for reestablishing core cooling flow under conditions of sump blockage. Therefore, transitioning from this guideline to SACRG-1 earlier in the guideline is premature.

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6. REFERENCES 1) NRC Bulletin 2003-01: POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON

EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS.

2) NRC Staff Responses to Industry Pre-Meeting Questions and Comments on Bulletin 2003-1 Provided in Support of June 30, 2003 NRC Public Meeting

3) Revised NRC Staff Responses to Industry Questions #40, #58, and #61 Regarding Bulletin 2003-01.

4) LA-UR-02-7562, The Impact of Recovery From Debris-Induced Loss of ECCS Recirculation on PWR Core Damage Frequency, February 2003.

5) NUREG/CR-6808, LA-UR-03-0880, Knowledge Base for the Effect of Debris on Pressurized Water Reactor Emergency Core Cooling Sump Performance.

6) WCAP-16204, Engineering Evaluations and Analyses Report, Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SEE-0085), January, 2004.