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TRANSCRIPT
I , ?
i 1-L -
D, A__ML _
~~~A_ B LGopcmany
Westinghouse Non-Proprietary Class 3
If
Discussion onIncreased Steam Generator Tube Plugging
and Reload Methodology at St. Lucie Unit 2(Transition to WCAP-9272)
BNF SlieI(BNFL Slide 2 0 Westinghouse
Agenda1. Project Background2. Licensing Considerations
2.1. WCAP-92722.2. SER Compliance2.3. RSAC Changes
3. Development Phase Overview3.1. Process3.2. St. Lucie Unit 2 Licensing Basis3.3. Comparison of Current and Transition Methods
3.3.1. Identification of Key Assumptions3.4. Overview of Engineering Review
4. Reload Setpoints Overview4.1. Methods4.2. Uncertainties4.3. Basics
4.3.1. Trips4.3.2. TM/LP & A1 versus OTAT & f(A I)
5. Core Design - Power Shape Generation, RAOC6. T/H - Code, Core Limits, Correlation7. Setpoints Details
7.1. Implementation7.2. Uncertainties
8. RETRAN8.1. Code8.2. Modeling for St Lucie Unit 2
9. Steamline Break9 1. Methods Assumptions and Modeling (General)9.2. SLB Post-trip LOAC
10. Asymmetric SG transient11. Feedline Break12. Documentation Expectations
* Additional topics as time permits* Topics 4 & 7 have been combined and will be
presented on Day 2 per NRCs request
*BNFL Slide 3
CBNFL Slide 3 OWesinghouse
Section 1Project Background
(BNFL Slide 4 SlWestinghouse
Background. Background
- St. Lucie Unit 2:* CE NSSS with analog protection system* 16xl6CEfueldesign* Nuclear Design by FPL with ALPHA-PHOENIX- ANC
Currently uses PAC reload process - CESEC / TORC / FATES /1985EM/S1M
- Cycle 15 will support:* Increase from 15% to 30% SGTP* Reduced TDF (min. TS flow) of 335,000 gpm
Transition ZIRLO claddingTransition to WCAP-9272 reload Methodology
BNFL Slide 5 Westinghouse
Program Roadmap
|30% SGTP / Reduced RCS Flow
ZIRLOI Cladding |
WCAP-9272 Methodology
Re-analysis/re-evaluation of FSAR Chapter 15 Events
LOCA Non-LOCA
|Technical Specification Chne
-- ~Sbitta
Structural, etc.
*BNFL Slide 6 Wo�tinghouse
(BNFL Slide 6 O)Wetinghouse
Section 2Licensing Considerations
I*BNFL Slide 7 6J Westinghouse'OD"BNFL Slide 7 (OWesinghouse
Transition to WCAP-9272-P-A Methodology
* Successfully used in reload analysis of over 540 reactor cores (in use since
1985)
* Westinghouse Reload Safety Evaluation Methodology (WCAP-9272-P-A)
- Defines a bounding approach to the reload evaluation process
- Defines key safety parameters and their limiting direction
- Results in a Reload Safety Analysis Checklist (RSAC) approach for reload
analysis
- WCAP-9272-P-A is applicable to both non-Westinghouse and
Westinghouse reactors
8 BNFL Slide 8 OWesinghouse
Transition to WCAP-9272-P-A Methodology
* St. Lucie Unit 2 transition to WCAP-9272-P-A requires all UFSAR Chapter 15
events to be re-analyzed or evaluated (All limiting events would also need to
be re-analyzed to support 30% SGTP with associated RCS flow reduction and
implementation of ZIRLO)
* The Westinghouse and CE fuel and plant designs are similar and any minor
dissimilarities (i.e., typically input parameters but occasionally a model
change) can be accounted for, and do not invalidate the reload methodology
applicability or philosophy
* Code, selection, use and applicability will be described, explained and justified
OBNFL Slide 9 Wetinghouse
SER Compliance
All code packages that are planned to be used for FSAR cases have been
previously licensed or will be re-licensed as necessary with the NRC
Selection of code packages will be shown to be applicable to WCAP-9272-P-A
Principle areas of licensing focus:
- changes to existing codes and models or new codes and models, and
- changes to existing methodology or new methodology
* "New" means new with respect to the "intended application" (i.e., the
code/model or method was previously licensed, but has been
tailored/customized for the current application)
*BNFL Slide 10 Westinghouse
SER Compliance
Certain items to be submitted to the NRC for review and approval (see next
slide). Since these items would have been previously licensed, the specific
licensing application for St. Lucie Unit 2 should be straightforward
* By identifying changes and areas that may need NRC review, the NRC staffwill
be able to more accurately gauge their resource needs to support the review
* A presentation of changes to existing codes and models or new codes and
models and changes to existing methodology or new methodology will be
provided in the technical presentations
OBNFL Slide 11 Wetinghouse
SER ComplianceActivity
Meeting with NRC to Kick-off the Program
AddendumtoVIPRETopical *
(WCAP-14565-P-A)Acceptance Meeting for Addendum to VIPRE
Topical (WCAP-14565-P-A)Pre-submittal Meeting with NRC on Licensing
Amendment for St Lucie Unit 2Proposed Licensing Amendment for St Lucie
Unit 2 submittal (includes re-write ofChapter 1 5)
Acceptance Meeting for St. Lucie Unit 2submittal
Anticipated NRCSubmittal Date
4/17
5/03
6/03
8/20-21/03
1/04
2/04
Anticipated NRCApproval Date
4/27
5/04
6/03
8/20-21/03
10/1/04
2/04
Status
Completed
Submitted 6/03
Needs to bescheduledScheduled
On-schedule
Needs to bescheduled
* BNFL Slide 12 O Westinghouse
BNFL Slide 1 2 (OWestinghouse
Comparison of MethodsFunctional Discipline Current Code Used Proposed Code Used Com nCore Design ALPHA/PHOENIX- Same No change
P/ANC
Thermal-hydraulic TORC VIPRE Addendum submittal for incorporatingDesign ABB-NV & ABB-TV into VIPRE
(Submitted 06/2003)
Correlation CE-1 /ABB-NV ABB-NV Upgrade correlation with ABB-NVwhich is NRC-accepted for referencingin applications for the St. Lucie Unit 2fuel design
Fuel Rod Design FATES-3B Same No change
Transient Analysis (non- CESEC/STRIKIN-II/ RETRAN/FACTRAN/ Change is within the flexibility of theLOCA) TORC/COAST VIPRE/TWINKLE codes to model both Westinghouse and
CE NSSS
Large Break LOCA 85EM 99EM Upgrade to 99EM which isNRC-accepted for referencing inapplications for CE NSSS
Small Break LOCA Si M S2M Upgrade to S2M which is NRC-acceptedfor referencing in applications for CENSSS
*BN Slide 1 3 S 1Wetinghouse
WCAP-9272 Reload Safety Analysis Checklist (RSAC)
As noted previously, the reload analysis is based on a reference analysis as
documented in a licensee's FSAR
- These analyses cite the key input assumptions and key input parameters
that have the most significant impact on a particular event and specify thecorresponding codes and methods used
- These key input parameters form the basis of Westinghouse's analysis for
the particular plant (i.e., these key input parameters and other inputparameters form the basis of a Safety Analysis Checklist (SAC), or"Baseline Neutronics")
- The SAC (or Baseline Neutronics) becomes the Reload Safety Analysis
Checklist (RSAC) for subsequent reload analyses/evaluations
(BNFL Slide 14 (SWestinghouse
Section 3Development Phase Overview
(BNFL Slide 1 5 *Westinghouse
Process
* General Approach
- Apply standard Westinghouse WCAP-9272 approach, recognizing:
Where changes are required to provide a technically appropriate
modeling of the unique features of the St Lucie Unit 2 design,
operations and Tech Specs
* Where licensing or other considerations warrant a different approach
* Slide 16 Westinghouse
Process
* General Approach
- Do not assume that the current licensing basis assumptions apply to
WCAP-9272 approach or that WCAP-9272 conventional wisdom applies
to St. Lucie 2
* Study each event using first principles to develop strategies and key
assumptions for each event
- Do the homework first
BNR Slide 1 7 Westinghouse
St. Lucie Unit 2 - Licensing Basis
Objectives
- Review and understanding of the licensing basis
0 Expert meeting June 2002
- Review and understanding of the unique features of the St. Lucie Unit 2
design, Tech Specs and operations
- Identification of methods to be used, and the basis for these choices
- Evaluation of the differences between the current basis and the basis
arising from the change in methodology
- Identification of key assumptions for the project technical activities
(BNFL Slide 18 (Wetinghouse
St. Lucie Unit 2 - Licensing Basis
Objectives
- Development of technical and licensing strategies for scoping activities,
definition of event requirements (cases), and outlines for methodsstructured around the standard methods for the technologies being used
- Outline the production phase of the project in which the analyses and
evaluations supporting the January 2004 submittal would be performed
• Extensive study was made of the current St. Lucie Unit 2 licensing basis
- Experts meeting-June 2002
- Review of analysis basis material
(BNFL Slide 19 Westinghouse
Comparisons of Current and Transition Methods
* Comparisons of Current and Transition Methods were undertaken
- ntra-disciplinary meetings to share information, requirements and map
preliminary analysis strategies
- Inter-disciplinary meetings to address interface requirements and
consistency of assumptions and strategies
* Technical Strategies were mapped for each event and reviewed for technical
and licensing appropriateness
- Engineering Review- February 2003
@BNFL Slide 20 OWestinghouse
Comparisons of Current and Transition Methods
Continuation of Current Methods
. LOCA
* Fuel Performance
* Mechanical Design
* Steam Generator Tube Rupture
* Containment analysis
OBNFL Slide 21 Westinghouse
Comparisons of Current and Transition Methods
Margin Considerations
* A preliminary assessment of margin was performed for key events where 1)
historical margin challenges existed, or 2) changes in methods or assumptions
made margin evaluation indeterminate to provide confidence in the viability of
the transition
* Slide 22 O Westinghouse
Comparisons of Current and Transition Methods
Identification of Key Assumptions
Based on the technical strategies and the methods requirements, key
assumptions were identified and confirmed between FPL and Westinghouse
- Includes changes in some assumptions based on margin considerations
(elimination of full power positive MTC, etc.)
- The strategies for analysis were identified and refined through
consultation with FPL, especially in areas of noteworthy differences
• Setpoints/ Uncertainties
* Ful power MTC
* Significant changes in analysis methodology
O BNFL Slide 23 Westinghouse
Overview of Engineering Review
* Focus on
- Aspects for which changes from the current licensing basis
- Proposed changes from standard methods to address the unique features
of the St. Lucie Unit 2 design, Tech Specs and operations
* The presentations which follow are structured around the Engineering Review
material, updated to reflect completed actions and results where available
BNFL Slide 24 9We�in�ouseBNFL Slide 24 . OWestinghouse
1 ---- 7
Section 4 & 7Reload Setpoints Overview & Setpoint Details
BNF Slde2 e We7ighus(DBNFL Slide 25 (sWestinghouse
Introduction
Westinghouse and St. Lucie Thermal Margin Protection Functions a,c
BNFL Slide 26 Westinghouse
B)1NFL Slide 26 O)Westinghouse
Design Basis for Thermal Margin Trips
* Design Basis for OTAT and TM/LP Reactor Trip Functions- Ensures that the DNB design basis is satisfied for a wide range of RCS
temperatures, pressures, powers and axial power shapes
- Ensures that vessel exit boiling is precluded to ensure that AT isproportional to power
BNFL Slide 27 �Westinghouse(BNFL Slide 27 GWetinghouse
Inputs for Thermal Margin Trips
* OTAT and TM/LP Trip Functions Based on the following Inputs
- Power (AT as indicated by hot minus cold leg temperature in each loop)
- Temperature indication (OTAT => Tavg, TM/LP => Tinlet)
- Pressurizer pressure (range limited by low and high pressure trips)
- Axial Shape as defined by excore detectors (OTAT => top minus bottom
TM/LP => Bottom minus top divided by total power)
* Slide 28 O Westinghouse
Thermal Margin Trip Equations
* Westinghouse Overtemperature AT Reactor Trip function:
Power = K - K2 (Tavg - Tavg') + K3 (P - P') - f(AI)
Sample: Power= 1.35 -0.018 (Tavg - 588') + 0.0085(P-2250) -f(Al)
* St. Lucie TM/LP Reactor Trip function:
Pvar = 1 4 00 x QDNB + 17.85 x Tin - 9410
where QDNB= QR1 function x A 1 function
Rearranging: Power = 1.33 - 0.01275 (Tinlet - 549) + 0.000714 (P- 2250)
AlSlide 29
9 Westinghouse*BNFL Slide 29 (OWestinghouse
Thermal Margin Trip Equations
* Westinghouse Overtemperature AT f(Al) Function- Reduces the setpoints for skewed axial power shapes based on top minus
bottom excore signal (Al)
f(AI)
0.0AI
*BNFL Slide 30 Westinghouse
(BNFL Slide 30 Westinghouse
Thermal Margin Trip Equations
* St. Lucie Thermal Margin / Low Pressure A 1 Function- Reduces the setpoints for skewed axial power shapes based on bottom
minus top excore signal divided by total (ASI)
Al
1.0ASI
BNFL Slide 31 WestinghouseGBNFL Slide 31 Wetinghouse
Core Thermal Limits
* Core Thermal DNB Limits- Westinghouse assumes a reference axial power shape (1.55 Chopped
Cosine) to generate the OTAT setpoint
TinletExit Boiling Limits
DNB Limits
High Pressure
Nominal Pressure
Low Pressure
0.0 Power
BNFL Slide 32 Westinghouse
OBNFL Slide 32 O)Wetinghouse
OTAT Reactor Trip & Core Thermal Limits
* Illustration of OTAT reactortrip with f(Al) = [No penalty]
Tavg Steam Generator SafetyValve Line
,, -
N~ N
NAOvrepraueA
Overpower AT Reactor Trip
I~ High Pressure
I Nominal Pressure
+^ Low Pressure
N
Power0.0
BNFL Slide 33 G WestinghouseOBNFL Slide 33 (OWestinghouse
Setpoints: TM/LP Reactor Trip & Core Thermal LimitsIllustration of TM/LP reactor trip with Al = 1.0 [No penalty]
Tinlet
- -
N%
"T s
Thermal Margin / Low Pressure *.
Steam Generator SafetyValve Line
Variable High Power (AT) Reactor Trip
High Pressure
\ Nominal Pressure
\, Low Pressure
*N
N I
0.0 Power
BNFL Slide 34 Westinghouse
BNFL Slide 34 (Westinghouse
OTAT Core Thermal Limits for Skewed Shapes
* Locus of Conditions where DNBR is at the limit- Used to define the OTAT f(AI) reset function
0.0 Ai
BNR Slide 35 Westinghouse
TM/LP Core Thermal Limits for Skewed Shapes
Locus of Conditions where DNBR is at the limit
- Used to define the TM/LP Al function
Power
0.0
Slide 36
ASI
*BNFL (OWestinghouse
Check of the TM/LP Reactor Trip Function
Core thermal limits, which include both DNB and exit boiling limits, aregenerated for a wide range of power levels and pressures
The TM/LP reactor trip function, with a bounding ESCU Penalty Factorincorporated into the QR, function and a gamma bias supported by the CEAwithdrawal at power event (-1 75 psi), is determined
The TM/LP trip noted above bounds the core limits from the low pressure tripsetpoint to the high pressure trip setpoint, for temperatures/powers from the steam generator safety valves to a power of 120%
, BNFL Slide 37 Westingouse
Setpoints: TM/LP Trip Function ESCU Penalty Factor
The uncertainties accounted for in the current ESCU Penalty Factor
analysis remain unaffected by the switch to the WCAP-9272 philosophy.
ESCU Uncertainties included in ESCU Penalty Factor: a, c
BNFL Slide 38 G Westinghouse(BNFL Slide 38 Westinghouse
Setpoints: Other Reactor Trip Functions
The following compares other reactor trip functions.
St. Lucie Unit 2 Voatle (Westinahouse olant)Variable High Power - High (107% of RTP)
Variable High Power - Minimum (15% of RTP)Pressurizer Pressure - High (2370 psia)Pressurizer Pressure - Low (TM/LP 1900 psia)Reactor Coolant Flow - Low (95.4%)Steam Generator Pressure - Low (626 psia)Steam Generator Level - Low (20.5% NRS)
High Neutron Flux- High (109% of RTP)
High Neutron Flux - Low (25% of RTP)Pressurizer Pressure - High (2400 psia)Pressurizer Pressure - Low (1975 psia)
Reactor Coolant Flow - Low (90%)Steam Generator Pressure - Low Si (600 psia)Steam Generator Level - Low (35% NRS)
* Slide 39 ()Westinghouse
I
Section 5Core Design - Power Shape Generation, RAOC
BNFL Slide 40 c�We�tinghouse(BNFL Slide 40 (Westinghouse
RAOC Condition I
* Standard 1 D axial model generation
* RAOC EVALUATION.7
.-
a, c
L*BNFL S eWestinghouseSlide 41
RAOC Condition I
FIGURE 4
ST LUCIE UNIT 2 CYCLE 13AO and AFD BAND COMPARISONNO ASI UNCERTAINTY APPLIED
o110H lll HM11111111|1111111111111111 mm1
I TI11-1S. +100) IIIIIIIIIII (*R. .J.Vur1111= . - n 11 11 1 1 111 I I111
I. . . ......... 1 11 .. t _._
V-I
^_v^st W AFD BAND
i 1 0
-11111
.. . . . . . . . .. . . . . ... . ..H . _ . . . _. . . .. . . . . . .. . . .. . . . . . .
I ilt! 1IHIIIIIIIII IIII 1 H I l'U I I I I PUI+. |Fs I5
I I N I I I I -------- n t: . .. . . . .
11111111111. 11. ... . .. .....
50
-30 .*50- - -- - -- -40Ll1 11 tt [..111111111
j:;-,
I -
* -100 OR AO()
APD () I
,5 , 5
_V . , - -,_ _ f _
-70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70
PERIPHERAL ASI * -100 / AO () / AD (%)
BNFL Slide 42
WesthighouseBNFL Slide 42 O@Westinghouse
RAOC Condition I
* RAOC EVALUATION (continued)a, c
GBNFL Slide 43 BdWestinghouse
RAOC Condition I
FIGURE 1
ST LUCIE UNIT 2 CYCLE 13AO and AFD BAND COMPARISON8% ASI UNCERTAINTY APPLIED
FIGURE 2
ST LUCIE UNIT 2 CYCLE 13AO and AFD BAND COMPARISONNO ASI UNCERTAINTY APPLIED
1101 110 l111 111111 11111 11111 II III III 11 1111111 IIIIIII1 l iii
Illlllrl~lllll!-------- =lllll1llll!!l100 l -23.100 4 I(+8. 4
n _f jj ZUU
_ 90
:
9 80
70-, -0
.. . . . . . . . . . . . . .I _ _ I -I ... v [I§ l | x I ...... .| T T |
a.0Ia-
90;
bsU
. I I I I 14 1 1 1 1 1 1 1 ....................11'd11-11ASI * -100 OR
A - - -AFD (I
AO (W)-'U 111111 . 11
1(-50 -+6S) ASI * -100 OR
AFD M%)
A (1 .651,0,.ril..,,-,--
. . .. . . . . . .
izni I I I 1 1 l l r l [ 2 __ ji =6u11 11 1 11 1 II II I II II II I I II II
5bU
.. . ... . . . . .
4C11 _ m IIIli 1r 11 ~l~ l rIII IIINIIII I I II 1 l il H I II III III -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70
PERIPRAL ASI * -100 AO %) / MD (I)
-70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70
PERIPMAL ASI * -100 / AO 00 I AJ D V
* BNFL Slide 44 Westinghouse(DBNL Slide 44 (SWestinghouse
RAOC Condition I
* RAOC EVALUATION (continued)
- Each axial power shape analyzed to determine if the linear heat rate
constraints are met
a, c
BNFL Slide 45 SeWestinghouse
RAOC Condition IFIGURE 5
ST LUCIE UNIT 2 CYCLE 13MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT
(-0.16, +0.23 ASI BAND)8% ASI +2% CLOR UNCERTAINTY APPLIED
FIGURE 6ST LUCIE UNIT 2 CYCLE 13
MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT(-0.08, +0.15 ASI BAND)
0% ASI +2% CALOR UNCERTAINTY APPLIED
I14. to o, 3..0 I(12.0, 13.0 I
...........
13.0
12.0
11.0
10.0
9.0
8.0
7.0
6.0
+
-
'-
SX
z
15.
14. p 0.0, 13.0 (12.0, 13.0 I
13.0
12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.o
4.0
100% -
100 -
70% FAC POWERSa
50% FAC POWERS
100% - 70% FAC PC015.01
KJERS Eii::.: -- . - -
- 50% FAC PC4.0
3.0 3.C
2.0 2.0
1.0 I0 1 2
BOTTOM
3 4 5 6 7 8 9 10 11 121 . 0r-t -- tf
0 1 2
BOTTOM
3 5 6 7 8 9 10 11 12
CORE HEIGHT (FEET) TOP CORE HEIGHT (FEET) TOP
OBNFL Slide 46 (sWestinghouse
RAOC Condition IFIGURE 7
ST LUCIE UNIT 2 CYCLE 13MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT
(ASI BAND COMPARISON)INCLUDES 2 CALORIMETRIC UNCERTAINTY
15.0
14.O ( 0., 130 I(12.0. L3.0 )
13.0
12.0
11.0
10.0
9.0
8.0
7.0
S.0
4.0
-0.16, +0.23 ASI BAND-. - - -
).08, +0.1!I AS I BAND
3.0
2.0
1.01:0 1 2 3 4 5 6 7 8 9 10 11 12
TOPBOTTOM CORE HEIGHT (FEET)
DBNFL Slide 47 SeWestinghouse
RAOC Condition I
Conclusions - Condition I RAOC Evaluations- Feasibility for implementing RAOC in future cycles for St. Lucie Unit 2
confirmed- Results are as expected- T/H design has confirmed acceptable DNB results for verification of linear
heat rate LCO should the incore detectors become inoperable- A change in the Axial Shape Index (ASI) breakpoints from 65% power to
50 % power will be proposedReduces degree of bowing in AFD space while allowing sufficientdegree of operational flexibility
BNFL Slide 48 Westinghouse
RAOC Condition II
* Standard Westinghouse Condition I accident studies performed- Cooldown transients- Control rod withdrawal- Boration/Dilution
* Note: Manual rod control only - no automatic rod withdrawalcapability in St. Lucie Unit 2
GBNFL Slide 49 Westinghouse
RAOC Condition I
FIGURE 8ST LUCIE UNIT 2 CYCLE 13
MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT(-0.16, +0.23 ASI BAND)
CONDITION II - ROD MALFUNCTION
i14IE994
w
9zm0
x
i
5
IR
17.0
lS n
I ;
1A
13.0
12 .
FIGURE 9ST UCIE UNIT 2 CYCLE 13
MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT(-0.16, +0.23 ASI BAND)
CONDITION II - BORATION/DILUTION
17. ... T.I.0....
1 4 .0 T I... . . .. . . . . . 50 P
12.0 ,,.,_G TT7 _
> l8 i0 II 1111 &
B 1.0 A- 111.__AW B s~~o 4 lNTITIO FRO 70i PWER4w
4.0 ....... INITIATION FROM 10% POWER
11.
A1A
4
7
0 1 2
BOTTOM
4 5 6 7 8 9 : I.0 11 12TOP
0 1 2 3 4 5 6 7 8 9 10 11 12
BOTTOM CORE HEIGHT (FEET) TOPCORE HEIGHT (FEET)
* BNFL Slide 50 �Westinghouse(BNFL Slide 50 (sWestinghouse
RAOC Condition II
* Conclusions - Condition 11 RAOC Evaluations- Feasibility for implementing RAOC in future cycles for St. Lucie Unit 2
confirmed- Results are as expected - Comparisons to sister Turkey Point Units show
similar behavior- Ample margin exists to limits
BNFL Slide 51 Westinghouse
1 ---- 7
Section 6T/H - Code, Core Limits, Correlation
I S (BNFL Slide 52 (OWetinghouse
OutlineT/H Analysis Approach
ABB-NV with VIPRE
St. Lucie 2 VIPRE Model
Revised Thermal Design Procedure (RTDP)
* Core Thermal Limits for TM/LP Trip
RAOC Power Shape DNB Verification
Accident Statepoint Analysis
BNFL Slide 53 O)Westinghouse
T/H Analysis Approach
• Utilize NRC-approved bounding evaluation results, not impacted by WCAP-9272, for St. Lucie 2 core and CE-type fuel
- Engineering hot channel factors- Core parameter and peaking factor uncertainties, etc.
* Apply NRC-approved code and method- Westinghouse version of VIPRE-O1 (VIPRE)- Revised Thermal Design Procedure (RTDP)- ABB-NV DNB correlation
Adjustment to existing design process- Core thermal limits for TM/LP- RAOC power shape verification
BNFL Slide 54 OWestinghouse
CE-ABB DNB Correlation
* CE-ABB DNB correlation (CENPD-387-P-A)- ABB-NV for 1 4xl 4 & 1 6xl 6 non-mixing vane fuels- ABB-TV (1 4x1 4 Turbo only)
* Qualification with VIPRE submitted to NRC- Addendum 1 to WCAP-1 4565-P-A (June 03)- VIPRE equivalent to TORC for DNBR calculations- Current 95/95 DNBR limit of 1.13 remains unchanged- Current applicable range remains valid
(BNFL Slide 55 c)Westuighouse
St. Lucie 2 VIPRE Model
One-pass model (WCAP-1 4565-P-A)- Core & hot channels modeled in one calculation- Applicable to CE-type PWR cores- Designated hot channels and locations- Model considers hydraulic loss due to core plates
* Bounding power and flow distributionsa, c
BNFL Slide 56 d 5Wetinghouse
VIPRE 25-Channel Model (1/8th HA)a, c
BNFL Slide 57 S eW estinghouse
VIRPE 25-Channel Model (1/8th Core)a, c
*BNFL Slide 58 �WestinghouseBNFL Slide 58 (OWesinghouse
Revised Thermal Design Procedure (RTDP)
• RTDP (WCAP- 1 397-P-A) is similar to current ESCU- Statistical DNB design method- Applied to most Westinghouse plants including Turkey Point- Current uncertainty values remained unchanged
* Uncertainties to be convoluted for 95/95 DNBR limit- Core parameters- Hot channel factors- Engineering manufacturing tolerances- DNB correlation, subchannel and transient codes
OBNFL Slide 59 (OWestinghouse
RTDP Application
St. Lucie 2 application in compliance with SER conditions
* RTDP DNBR limit verified and applied at DNB limiting conditions- Loss of flow & seized rotor (locked rotor)- Pre-trip steamline break (HFP SLB)- CEA withdrawal at power (rod withdrawal)- CEA drop and static rod misalignment, etc.
* RTDP not used- Hot zero power steamline break- CEA withdrawal from subcritical
*BNFL Slide 60 S eWestinghouse
Core Thermal Limits for TM/LP Trip
* Input for TM/LP trip setpoint confirmation
* Core Thermal Limits: T-inlet vs. Power- DNBR
- ABB-NV maximum quality
- Vessel exit boiling
- At different pressure levels
* AT-inlet vs. (-ASI) limit accounts for axial shape effectsI a,c
BNFL Slide 61 GWestinghouse
Axial Power Shapes for DNB Analysis
* Reference axial power shape for HFP RTDP events- Loss of flow, seized rotor, dropped rod, etc.- Based on nominal operating range & conditions (Condition I)- Affected by ASI operating limits in Fig. 3.2-4 of COLR
• Accident shapes for TM/LP Trip- Reference AT-inletvs.ASI limit- Condition II RAOC shapes
• Accident specific power distributions- Steamline break- HZP events
, BNFL Slide 62 OWestinghouse
Accident Statepoint Analysis
VIPRE transient calculations- Model and method consistent with WCAP-1 4565-P-A- Fuel rod model initialized with FATES temperature data
* DNB limiting accidents to be analyzed:- Loss of flow- Seized rotor
- Steamline break- RCCA malfunction, etc.
(DBNFL Slide 63 OWestinghouse
Summary
* ABB-NV has been validated with VIPRE
* St. Lucie 2 VIPRE model consistent with WCAP-1 4565-P-A
* DNBR limit for transient analysis statistically determined using RTDP
* Core limits define DNB basis for TM/LP trip setpoints
* RAOC power shape verification is conducted on cycle-specific basis
* Accident analysis similar to those for other PWR
*BNFL Slide 64 WestinghouseBNFL Slide 64 (OWestinghouse
I
Section 8RETRAN Model
I BNFL Slide 65 O Westinghouse
(BNFL Slide 65 OWestinghouse
RETRAN Code
* No Code Changes Are Required to Support the St Lucie 2 ModelImplementation
BNFL Slide 66 Westinghouse(BNFL Slide 66 (sWestinghouse
St. Lucie 2 RETRAN Model
Changes made to:- Nodalization- Control/Protection Systems
No new code options are implemented in the St. Lucie 2 Model that were notaddressed in WCAP-1 4882-P-A ("RETRAN Modeling and Qualification forWestinghouse Pressurized Water Reactor Non-LOCA Safety Analyses")
*BNFL Slide 67
(BNFL Slide 67 (Weslinghouse
St Lucie 2 RETRAN Model
* Although the SER for WCAP-1 4882 limits the applicability of the WCAP to
Westinghouse designed PWRs, many portions of the WCAP are equally
applicable to the CE model developed for St. Lucie 2- The modeling options described in WCAP-1 4882 are equally applicable to
the St. Lucie 2 model- The SER limitations discussion in WCAP-14882 are equally applicable to
the St. Lucie 2 model
*BNFL Slide 68
GBNFL Slide 68 Westinghouse
St Lucie 2 Reactor Coolant System
0 The changes made for the CE design for St. Lucie 2 include: a, c
0
lOther change made:
La,c
*BNFL Slide 69 WestinghouseGBNFL Slide 69 O)Westinghouse
RCS Diagrama, c
BNFL Slide 70 �We�tinghouseGBNFL Slide 70 oWeinghouse
Vessel Diagram'I a,c
BNFL Slide 71 Westinghouse
(BNFL Slide 71 (OWestinghouse
Steam Generator DiagramI a,c
OBNFL Slide 72 BWemtinghouse
St. Lucie 2 RETRAN Model Changes
Control/Protection System Changes compared to WCAP-1 4882-P-A Model
- Except for RCS flow measurement, sensors and sensor locations are similar
- Actions that can be implemented (reactor trip, safety injection, valve
opening/closing, etc.) are effectively the same- Processing of the sensor protection signals is different- Basic control system layout is similar to Westinghouse models
BNFL Slide 73 9We�tinghouseBNFL Slide 73 Westinghouse
St. Lucie 2 RETRAN Model Changes
Protection System modeling reflects St. Lucie 2 specific design, including:- RCS Flow measurement based upon steam generator delta-P- Reactor trip functions
* Variable High Power* Thermal Margin Low Pressure** Start-up Rate* Local Power Density** Asymmetric SG Transient* Low Flow* High Pressurizer Pressure* Low SG Level* Low SG Pressure* Turbine Trip
* User-defined ASI vs Time
*BNFL Slide 74 Westinghouse
St. Lucie 2 Control/Protection Modeling
* High SG Level- Shut FW Reg. Valve for Affected SG
* High-High SG Level- Turbine Trip
- Trip FW Pump(s), Close MFW Pump Discharge Valve(s)
*BNFL Slide 75 GJ Westinghouse(BNFL Slide 75 Westinghouse
St. Lucie 2 Control/Protection Modeling
CE Unique Reactor Trips- Thermal Margin Low Pressure (similarto OTAT)- Variable High Power (automatically reduced for downpower transients)
- Startup Rate Trip (Decades/minute - similar to PFRT trip)
- High Local Power Density Trip (ASI dependent)
* Low Steam Pressure- Reactor Trip (No SI)- MSIV / MFIV Closure (Separate Setpoint)
* Low SG Level- Reactor Trip- AFW initiation to Affected SG only
@>BNFL Slide 76 Westinghouse
St. Lucie 2 Control/Protection Modeling
Safety Injection- Initiates on Low Pressurizer Pressure Only- Starts Sl System- Starts Diesels- Limits PZR Heater Capacity
Low Flow Reactor Trip- Based on total of the two SG AP signals
(BNFL Slide 77 S eWestinghouse
Section 9Steamline Break
, . ,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~L-'m"BNFL Slide 78 SeW estinghouse
Pre-Trip SLB (HFP)
* RETRAN model developed
* Based on available protection systems and expected effects of the transient,the basic range of sensitivities were investigated.
- Inside and Outside Containment- Varying MTC- With and without offsite power- Break size
• Acceptance criteria- Peak linear heat rate- DNBR
*BNFL Slide 79 Westinghouse
Pre-Trip SLB - Analysis methods
The following trip functions are modeled:- Variable High Power reactortrip (including excore neutron detector power
signal and thermal power calculation)Effects of RPV downcomer density changes on the excore detectorsare specifically modeled
- Low Steam Generator Pressure reactor trip- High Containment Pressure reactor trip (Inside Containment breaks);
although available, not used
(3BNFL Slide 80 OWestinghouse
Pre-Trip SLB - Expectations/Conclusions
Large breaks must satisfy ANS Condition IV acceptance criteria, which allows
fuel failure
• All breaks expected to satisfy ANS Condition 11 acceptance criteria
* Results of sensitivity studies demonstrate that plant specific analyses should
analyze:- Inside containment- Most Negative MTC to produce trips on thermal power AT and low
steamline pressure- Without offsite power- Spectrum of break sizes
BNFL Slide 81 Westinghouse
Pre-Trip SLB - Heat Flux as a function of Break Size and MTCa, c
BNFL Slide 82 Westinghouse
(DBNFL Slide 82 Oestinghouse
Pre-Trip SLB - Nuclear Power: 2.5ft2 break vs 3.2 ft2 break
C
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*BNFL Slide 83 S eWestinghouse
Pre-Trip SLB - Heat Flux: 2.5 ft2 break vs 3.2 ft2 break
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*BNFL Slide 84 Wetinghouse
Pre-Trip SLB - Pressurizer Pressure: 2.5 ft2 vs 3.2 ft2 break
Eo2
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BNFL Slide 85 (dWestinghouse
Pre-Trip SLB - Vessel Inlet Temps: 2.5 ft2 vs 3.2 ft2 break
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*BNFL Slide 86 Westinghouse
Pre-Trip SLB - SG Pressure: 2.5 ft2 vs 3.2 ft2 break
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*BNFL Slide 87 G Westinghouse
Pre-Trip SLB - SG Loop Steam Flow: 2.5 ft2 vs 3.2 ft2 break
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OBNFL Slide 88 OWestinghouse
Pre-Trip SLB - DNBR: 2.5 ft2 vs 3.2 ft2 break
4.5
4
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1.5
*BNFL Slide 89 WestinghouseBNFL Slide 89 Wetinghouse
Post-Trip SLB (HZP)
* Transient is very similar to typical Westinghouse transient, except that LSPdoes not invoke a Safety Injection (use LPP instead)
* Analysis assumes offsite power available- Low flow case (without offsite power) has historically been non-limiting
with respect to the SLB case with offsite power available based on WCAP-9226-P-A, Rev 1. CE plant design does not present any uniquecharacteristics that would prevent similar behavior
- Confirmed through developmental analysis for St. Lucie* Iterative process with Core Design to achieve conservative reactivity swing* The analysis will demonstrate that the DNB design basis is satisfied
0BNFL Slide 90 Westinghouse
Post-Trip SLB (HZP Trip): SG Pressure
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* Slide 91 Sd9Westinghouse
Post-Trip SLB (HZP Trip): Steamline Break Flow
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*BNFL Slide 92 OWestinghouse
Post-Trip SLB (HZP Trip): Pressurizer Pressure
200
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Time (s)
GBNFL Slide 93 SeWetinghouse
Post-Trip SLB (HZP Trip): Vessel Inlet Temperatures
550
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BNFL Slide 94 Westinghouse
Post-Trip SLB (HZP Trip): Heat Flux
.15
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BNFL Slide 95 Westinghouse
Post-Trip SLB (HZP Trip): Core Boron
25
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BNFL Slide 96 S 9Westinghouse
Post-Trip SLB (HZP Trip): Core Reactivity
0a>cw
9u
BNFL Slide 97 �Westinghause(BNFL Slide 97 (OWestinghouse
Section 9aPost Trip Steamline Break Analysis
(Hot Zero Power with Loss of Offsite Power)
L- I
GBNFL Slide 98 Ostfinghouse
Introduction
* Case without (w/o) offsite power is characterized with low RCS flow- Core power driven natural circulation- Requires detailed crossflow calculation in reactor core
* WCAP-9226-P-A, Rev. 1 conclusion re-validated for St. Lucie 2- Case with offsite power bounds case w/o offsite power- No change to analysis approach or method
BNFL Slide 99
GBNFL Slide 99 Westinghouse
Validation Process
Accident statepoints from RETRAN- For both cases with or w/o offsite power- Loop temperatures and flows, pressure, core boron, power vs. time
Power distributions from SPNOVA/VIPRE- At DNB limiting time step- Additional reactivity check with RETRAN at other time steps
DNBR calculation using VIPRE- Subchannel model- W-3 and McBeth DNB correlations for low flow/low pressure
*BNFL Slide 100 Westinghouse
SPNOVA/VIPRE Coupling
* SPNOVA/VIPRE coupling described in WCAP-1 5806 (SER issued in 07/03)
- Executed in either steady state or kinetic mode
- SPNOVA static neutronic solution consistent with ANC
- Same nodes between SPNOVA and VIPRE- Auxiliary program ANCKVIPRE coordinates data transfer
* Data interface similar to previous calculations for WCAP-9226- 3-D core power distribution from SPNOVA to VIPRE- Coolant density and temperature from VIPRE to SPNOVA
- VIPRE fluid solution accounts for cross flow effects
*BNFL Slide 01 OWeing~house
Validation Results_ a,c
* Results and conclusions consistent with WCAP-9226-P-A, Rev. 1
* McBeth DNB correlation also shows similar conclusion
BNFL Slide 102 �WestinghouseBNFL Slide 1 02 westinghouse
I
Section 10Asymmetric Steam Generator Transient
IBNF- SIBNFL Slide 1 03 CWestinghouse
ASGT
* ASGT is an event that causes a rapid imbalance in heat transfer between the
two SGs
* Initiated by one of the following:- single MSIV closure- feedwater flow reduction to one SG- excessive feedwater flow increase to one SG
* The rapid rate of closure of an MSIV results in the most rapid temperature tiltacross the reactor core
9BNFL Slide 104 Wesfighouse
ASGT
ASOGT is classified as an ANS Condition 11 event
* ASGT event is primarily analyzed to ensure that the DNBR SpecifiedAcceptable Fuel Design Limit (SAFDL) is satisfied
* Reactor protection provided by High Steam Generator secondary pressure APreactor trip (functionally a part of the TM/LP trip)
*BNFL Slide 105 �We�tinghouseCBNFL Slide 1 05 (Wstinghouse
ASGT
* .Since ASGT is being analyzed with respect to the DNB related acceptancecriteria, the analysis will be treated as a typical Westinghouse Revised ThermalDesign Procedure (RTDP) analysis
- Measurement uncertainties are incorporated in the DNB correlation
* Parametric studies on SG tube plugging level have been performed
BNFL Slide 106 Westinghouse(DBNFL Slide 1 06 O)Westinghouse
I
Section 1 1Feedline Break
(BNFL Slide 1 07 Westinghouse
Feedline Break
Typical Analysis methodology for Westinghouse plants provides FSARChapter 15 documentation on the long term heat removal capability of theAFW System
- Cases performed both with, and without, offsite power- Overpressurization bounded byTurbineTrip (Condition 11) event- Fuel failure/dose bounded by SLB (for FLB)
Current St. Lucie Unit 2 analysis methodology analyzes foroverpressurization, fuel failure, and dose
- Long term heat removal addressed in FSAR Chapter 10- Feedline break is a limiting overpressure event due to methodology
applied
@(BNFL Slide 108 Westinghouse
Feedline Break
Analysis Methodology to be implemented:- Leave the St. Lucie Unit 2 Chapter 10 analysis methodology
intact/unchanged- Use Westinghouse Chapter 15 arguments as to bounding events for fuel
failure/dose- Address overpressurization for FLB through analysis with typical
Westinghouse assumptionsAssume the feedring does not fall on the tube sheet
*BNFL Slide 109 Westinghouse
I 7 - :
Section 1 2Documentation Expectations
II BNFL Slide 110 0 Westinghouse(BNFL Slide I110 Westinghouse
Documentation Expectations
. Submittal- Typical licensing submittal format
* Descriptions of analyses (key assumptions, criteria, codes & methods,
etc). FSAR updates* 50.92 for proposed Tech Spec updates
* Schedule- January 2004
*BNFL Slide 111
�Westinghouse(BNFL Slide I111 (OWesinghouse
Production Activities
* Overview & Discussions
* Questions
*BN WestinghouseSlide II12
I
A BNFL Group company