usq #gcx-2 preparation of piping engineering analyses …

USQ #GCX-2

PREPARATION OF PIPING

ANALYSES FOR WASTE TRANSFER

SYSTEMS

Manual

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TFC-ENG-DESIGN-C-60, REV A-3

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April 19, 2017

Ownership matrix

TABLE OF CONTENTS

1.0 PURPOSE AND SCOPE ................................................................................................................ 2 2.0 IMPLEMENTATION ..................................................................................................................... 2 3.0 RESPONSIBILITIES ...................................................................................................................... 2 4.0 PROCEDURE ................................................................................................................................. 3

4.1 General Methods ................................................................................................................. 4 4.2 Identify Inputs and Assumptions ........................................................................................ 5 4.3 Identify Design Conditions and Load Combinations .......................................................... 7 4.4 Determine Pressure and Stress Limits .............................................................................. 11 4.5 Perform Piping Stress Analysis ........................................................................................ 12 4.6 Prepare and Issue Analysis Report ................................................................................... 14

5.0 DEFINITIONS .............................................................................................................................. 15 6.0 RECORDS .................................................................................................................................... 15 7.0 SOURCES ..................................................................................................................................... 15

7.1 Requirements .................................................................................................................... 15 7.2 References ......................................................................................................................... 16

TABLE OF TABLES

Table 1. Inputs for Piping Analyses. .......................................................................................................... 18 Table 2. Assumptions for Piping Analyses. ............................................................................................... 21 Table 3. Screening Criteria. ....................................................................................................................... 23 Table 4. Pressure and Stress Allowances for ASME B31.3 Analyses. ...................................................... 25 Table 5. Pressure and Stress Limits for TSR AC 5.8.5 Analyses. ............................................................. 27 Table 6. Methods for Analyzing Seismic Loads. ....................................................................................... 31

TABLE OF ATTACHMENTS

ATTACHMENT A - FORMAT AND CONTENT OF PIPING ANALYSES .......................................... 32 ATTACHMENT B - SPEED OF SOUND DATA ..................................................................................... 34 ATTACHMENT C - EXAMPLE SCREENING CRITERION FOR COLUMN SEPARATION ............. 36 ATTACHMENT D - CREDIBLE OVER-PRESSURE CONDITIONS .................................................... 38

http://toc.wrps.rl.gov/rapidweb/PRO/index.cfm?pageNum=232

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PREPARATION OF PIPING ANALYSES

FOR WASTE TRANSFER SYSTEMS

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1.0 PURPOSE AND SCOPE (7.1.1, 7.1.2, 7.1.3)

This procedure provides methods and explains requirements for performing analyses of stresses

in waste transfer piping systems, or sub-systems, and related piping components.

This procedure applies to the analysis of new piping or modifications to existing piping that are

subject to the requirements in TFC-ENG-STD-22, and which are required to comply with the

requirements for design specified in ASME B31.3, “Process Piping.” Such analyses verify the

design stresses in piping systems due to internal pressure and longitudinal stress resulting from

sustained and occasional loads do not exceed the maximum allowable stress defined in

ASME B31.3.

This procedure also applies to evaluations of overpressure and flow transient conditions that may

occur in safety significant waste transfer systems (during a waste transfer) to satisfy the

requirements of Specific Administrative Control 5.8.5, “Waste Transfer System Overpressure

and Flow Transient Protection (SAC),” specified in HNF-SD-WM-TSR-006, “Technical Safety

Requirements,” TSR AC 5.8.5, and related specific administrative control (SAC) descriptions in

RPP-13033, “Tank Farms Documented Safety Analysis,” Section 4.5.7. Background information

necessary to understand transients and requisite analytical methods can be found in

RPP-RPT-54581, “Supplemental Basis Document for Waterhammer Calculations.”

Analyses and evaluations performed in accordance with this procedure also may be relied on to

fulfill the requirements for Defense in Depth Feature 29 (DID) in RPP-13033, Table 3.3.2.3.2-2,

“Other Defense in Depth Features (Non-Safety SSE and non-TSR Administrative Features).”

The methods, inputs, and assumptions defined in this procedure may be relied on in part to

evaluate waste transfer piping under the requirements established in RPP-RPT-52248, “Fitness

for Service Program Requirements,” or to evaluate piping which is not within the scope of

TFC-ENG-STD-22 and TSR AC 5.8.5, but which may be subject to requirements in ASME Code

Section B31.1, “Power Piping,” or Code Section B31.9, “Building Services Piping.”

2.0 IMPLEMENTATION

This procedure is effective on the date shown in the header and is applicable to evaluations and

analyses of waste transfer systems within its scope issued after the effective date.

Evaluations and analyses of flow transients (water hammer) issued prior to the effective date of

TFC-ENG-DESIGN-C-60, Revision A, will require confirmation that this methodology is met or

bounded as documented in a technical evaluation per TFC-ENG-FACSUP-C-03 prior to

satisfying the requirements of TSR AC 5.8.5, RPP-13033 Section 4.5.7 and/or DID Feature 29.

3.0 RESPONSIBILITIES

Responsibilities are contained within Section 4.0.

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4.0 PROCEDURE

This procedure defines the engineering activities required to prepare and issue pressure and stress

analyses of waste transfer systems and related piping supports as well as evaluations required by

TSR AC 5.8.5 and DID Feature 29. These analyses and evaluations demonstrate:

Requirements of ASME B31.3 are met for the design conditions of internal/external

pressure, sustained loads, and occasional loads for new or modified waste transfer

systems;

Requirements for DID Feature 29 are met, i.e., administrative and engineered features

credited to demonstrate that ASME B31.3 allowances are complied with, are identified as

DID features (note that engineered features are not required to be identified as DID if

there are no credible failure modes that prevent the credited function as documented [or

referenced] in the evaluation); and,

Requirements of TSR AC 5.8.5 are met, i.e., administrative and engineered features

credited to demonstrate that peak pressures and stresses resulting from potential waste

transfer pump or unanticipated overpressure or unanticipated flow transient during waste

transfer are less than limits established in the ASME Boiler and Pressure Vessel Code

(B&PVC), Section III, Division 1, Subsection ND for Service Level D (Section III), or

Code Case N-155-2 for Fiberglass Reinforced Thermosetting Resin (FRTR) pipe, Level

D Service Limits, are safety-significant SSCs or SACs (note that engineered features are

not required to be identified as safety significant if there are no credible failure modes

that prevent the credited function as documented [or referenced] in the evaluation).

The effects of a flow transient resulting from valve-induced water hammer, column separation, or

surge on waste transfer system are to be evaluated. As such, this procedure defines engineering

activities to:

Screen for the potential occurrence of a flow transient as a result of planned operations,

operator errors, or equipment failures; and

Evaluate peak pressures and stresses resulting from these events with respect to

ASME B31.3 allowances and Section III Service Level D limits or Code Case N-155-2

Level D Service Limits for FRTR piping, as applicable.

Note that if the action that initiates a postulated flow transient represents an off-normal event

(as in human error or equipment failure), the flow transient evaluation does not need to consider

additional independent events or failures such as waste transfer pump overpressure.

Waste transfer systems within the scope of this procedure may interact with pressure sources as

defined in TFC-ENG-STD-25 or other pressure sources established for conduct of maintenance

activities such as flushing or testing.

Piping design and analysis are iterative processes. As such, performance of the work steps

specified in this procedure may be performed out of sequence or repeated as needed to establish

analyses that are consistent with the requirements herein.

In cases where piping stress analyses prepared in accordance with this procedure are intended to

supplement prior approved calculations and examine specific load conditions not previously

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considered, only those work steps relevant to the design condition(s) being examined are required

to be performed.

4.1 General Methods

The following general methods are applicable to all analyses prepared in accordance with this

procedure.

Analysis of waste transfer piping for the effects of a flow transient shall treat loads

resulting from such events as occasional loads for compliance with ASME B31.3. For

existing and new jumper designs, if compliance with RPP-RPT-58773, “Assessment of

Safety Significant Piping Jumpers to Assure Excess Load Capacity for Potential Water

Hammer (Leak Check and Flush) Events,” is demonstrated and operating conditions are

bounded within the assessment limits, then no specific flow transient analysis is required

for leak check and flushing activities in the 200E DST waste transfer system when

utilizing the applicable service water system. Service water system sources and

configurations evaluated are as documented in Rev 0 of RPP-RPT-58773.

Primary waste transfer piping that is encased within a secondary confinement boundary

shall be subject to the rules established for Normal Fluid Service in ASME B31.3.

(Ref. ASME B31.3, Appendix M)

Analytical methods for longitudinal stresses (SL) due to sustained loads such as pressure,

displacement, and weight were not clearly defined in earlier editions of the B31.3 Code

(2008 and before). Determination of SL was clarified by B31 Case 178 and is

incorporated in ASME B31.3-2010 where paragraph 320, supplemented by Appendix S,

may be used as a method for determining SL. If the applicable Code of Record contains

the method for determining SL (such as ASME B31.3-2010), that method shall be used.

FRTR piping is covered under ASME B31.3 Chapter VII, Nonmetallic Piping and Piping

Lined With Nonmetals. Chapter VII, paragraph A302.3, shall be used for nonmetallic

piping to determining stresses due to sustained loads.

There are two paths identified in this procedure, one for existing waste transfer systems and one

for new systems or modification(s) to existing systems.

Evaluation of existing systems does not necessarily require recreation of the ASME Code

analyses but does require the identification of engineered and/or administrative feature(s)

that would be required to stay within ASME B31.3 allowances.

New systems or modification(s) to existing systems require ASME B31.3 analyses as

prescribed in this procedure and ASME B31.3 and requires the identification of

engineered and/or administrative feature(s) that would be required to stay within

ASME B31.3 allowances. For new jumper design, compliance with RPP-RPT-58773,

demonstrates sufficient capacity to stay within ASME B31.3 allowances for pressure

transient cases to support leak check and flushing using the applicable service water

system within the 200E DST waste transfer system.

Both existing and new systems/modifications to existing systems require the TSR

AC 5.8.5 analyses prescribed in this procedure and the identification and implementation

of safety-significant support SSCs and/or SACs that mitigate or eliminate the problematic

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condition(s) that would result in exceeding Section III Service Level D limits or Code

Case N-155-2 Level D Service Limits for nonmetallic piping.

4.1.1 Existing Waste Transfer Systems

Analyst 1. If engineered and/or administrative feature(s) are used to mitigate or

eliminate the problematic condition(s) that result in exceeding

ASME B31.3 allowances, identify these features as defense-in-depth

features.

2. Perform required steps for the TSR AC 5.8.5 analyses.

4.1.2 Identify Boundary of Analysis

Analyst 1. Identify the boundaries of the waste transfer system that is to be

analyzed using configuration-controlled documents.

2. Consider the scope described in ASME B31.3, paragraph 300.1, the

requirements in TFC-ENG-STD-22 and the physical configuration of

the existing or planned design.

3. For analyses required by TSR AC 5.8.5, consider the safety-significant

waste transfer primary piping system boundaries defined in RPP-13033,

paragraph 4.4.1.2. Waste transfer pump overpressure evaluations must

consider physically connected safety-significant waste transfer primary

piping systems, HIHTL primary hose assemblies, and isolation valves

for double valve isolation. (See RPP-13033, Section 3.3.2.4.3.5, for

definitions of physically connected.) Flow transient evaluations are

only required to consider the planned waste transfer route. The planned

waste transfer route includes the waste transfer primary piping systems,

HIHTL primary hose assemblies, and isolation valves for double valve

isolation that are pressurized by the waste transfer pump, or the gravity

head from the 242-A Evaporator vessel when the vessel contains waste,

up to the first closed isolation valve. The isolation valve is not required

to be safety significant with respect to through valve leakage. (See

RPP-13033, Section 3.3.2.4.3.5, for definitions of when the 242-A

Evaporator vessel contains waste).

4. Mark-up Piping and Instrumentation Diagrams (P&ID) and design

configuration drawings to depict waste transfer system to be analyzed

and its interconnections with other systems and process equipment.

4.2 Identify Inputs and Assumptions

The following inputs and assumptions apply to analyses prepared under this procedure.

4.2.1 Assemble Inputs

Analyst 1. Prepare a hydraulic grade diagram showing elevations of pressure

sources, discharge points, piping and components in the waste transfer

system being evaluated.

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2. For ASME B31.3 analyses, identify pressure sources and their

performance parameters (e.g., pressure, flow) (see Attachment D).

Pressure sources include but are not limited to:

Reservoirs – bounding density and elevation

Tanks – bounding density, elevation, and pressure

Pumps:

Parameters (i.e., head, flow, and discharge pressure) for

electrically-powered constant speed pumps shall be

determined by the manufacturer’s pump curve for the

pump/motor combination specified in the design.

Parameters for hydraulically- or pneumatically-powered

variable speed pumps shall be determined by the

manufacturer’s pump curve for the maximum pump

speed expected for operations (note that administrative

and engineered features credited in establishing the

maximum pump speed expected for operations need to

be considered for inclusion as DID features).

Parameters for electrically-powered variable speed

pumps shall be determined by the manufacturer’s pump

curve for the operating speed that corresponds to the

Overspeed Trip frequency defined per

RPP-CALC-23897, “VFD Driven Induction

Motor/Pump Performance Evaluation” (note that the

overspeed trip frequency needs to be considered for

inclusion as a DID feature).

3. For the TSR AC 5.8.5 analyses, identify pressure sources and their

performance parameters (e.g., pressure, flow).

For the hazard of overpressure, pump parameters shall be as

defined in TFC-ENG-STD-25, paragraph 3.4 (i.e., “unmitigated”

pump performance characteristics), unless safety-significant

SSCs or TSR SACs limit pump performance and the resulting

design conditions expected to act on interconnected piping.

For the hazard of a flow transient, pump parameters shall be as

defined in Step 2 above, i.e., consistent with analyses that

demonstrate requirements in ASME B31.3 are met, provided the

action that initiates the postulated flow transient is an

independent off-normal condition.

4. Assemble input data for the analysis (see Table 1). These data may be

supplemented by additional information as necessary to conduct the

analyses.

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4.2.2 Identify Assumptions

Analyst 1. Identify assumptions and the basis that are to be relied on for the

analysis.

Table 2 provides assumptions and basis that may be relied on in

the analyses.

4.3 Identify Design Conditions and Load Combinations

The following identify design conditions and load combinations applicable to the waste transfer

system for:

ASME B31.3 analyses; and,

TSR AC 5.8.5 analyses.

4.3.1 Identify Design Conditions and Load Combinations for ASME B31.3 Analyses

Analyst 1. Identify the pressure/temperature design conditions that shall be

considered in ASME B31.3 analyses, including but not limited to:

Pressure sources identified per Section 4.2.1, step 2

Elevation differences

Flow transients or surges (see step 2)

External pressure or differential pressure for negative pressure

service

Pressure relief provided in piping design shall be creditable in

determining the highest pressure that is expected to be imposed

on it, provided analysis of the relief design shows it complies

with requirements in ASME B31.3, paragraph 301.2.2 or A301

for nonmetallic piping (note that pressure relief features

credited in establishing the highest pressure that is expected

need to be considered for inclusion as DID features)

Fluid temperatures, ambient temperatures, solar radiation,

heating or cooling medium temperatures, and the applicable

provisions of ASME B31.3 paragraphs 301.3.2, 301.3.3, and

301.3.4 or A301 for nonmetallic piping (note that engineered

and administrative features credited in establishing these values

need to be considered for inclusion as DID features)

Operating pressure and temperature expected at maximum

metal or nonmetallic temperature conditions

Consider potentials for overpressure in Attachment D.

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2. Identify potential flow transient initiators (i.e., triggering events), see

Attachment D:

a. Examine piping system configuration and planned operations

and maintenance activities such as flushes or tests and identify

anticipated (i.e. planned and expected) events that may cause

changes in fluid momentum in piping and resulting surge, valve-

induced water hammer, or elevation-induced column separation.

b. Identify valve operations:

1) Where technical procedures anticipate valve

manipulation during conduct of waste transfer, flushing,

or testing, whether manual or automatic. Valve

operations do not need to consider inadvertent pump

operations when the procedure verifies that the pump is

not operating before the valve operation and therefore

are not considered transient initiators; or,

2) Where valves re-position automatically in the event of

loss of power or control (i.e., valves which “fail open” or

“fail closed”)

3) Screen each valve operation identified as a triggering

event for the potential occurrence of valve-induced water

hammer, according to the screening criteria in

Table 3(a).

c. Identify pump operations:

1) For planned filling of a voided piping system; and,

2) For planned pump start, stop, and emergency stop or

trip.

d. Identify cases where pressure sources (e.g., pump start, valve

opening) re-established pressure to waste transfer systems that

support a column separation condition per the screening criteria

in Table 3(b).

3. Identify the design pressure, P0, and design temperature, T0, for the

system analyzed per ASME B31.3, paragraph 301or A301 for

nonmetallic piping, for the conditions identified in Step 1 above or as

specified in design media, whichever is more conservative:

The pressure at the most severe condition of coincident internal

or external pressure and temperature (minimum or maximum)

expected during service.

4. Identify the design minimum temperature for the system analyzed per

ASME B31.3, paragraph 301 or A301 for nonmetallic piping, for the

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conditions identified in Step 1 above or as specified in design media,

whichever is more conservative.

5. Identify load combination for ASME B31.3 analysis of the Sustained

Load case: design conditions shall be consistent with requirements in

ASME B31.3, paragraph 320 or paragraph A302.3.3 for nonmetallic

piping.

6. Identify load combination for ASME B31.3 analysis of Occasional

Loads for the seismic case:

Design conditions (i.e., pressure and temperature) shall be

consistent with the Sustained Load case. This loading shall be

combined with seismic loads applicable to the performance

category and structural design criteria specified for the piping

(including anchor and nozzle movements)

Consider all potential load combinations for seismic

acceleration inputs:

Positive horizontal and positive vertical

Positive horizontal and negative vertical

Negative horizontal and positive vertical

Negative horizontal and negative vertical.

7. Identify load combination for ASME B31.3 analysis of Occasional

Loads for the flow transient case:

a. Identify the design conditions (e.g., pressure and temperature)

from Step 1 where screening criteria in Table 3(a) or 3(b) show

potential flow transients require a detailed analysis.

For valve operations, design conditions at the time of a

triggering event shall be those which produce the maximum

expected flow through the system, considering the pressure

source and fluid characteristics examined.

For pump operations, design conditions for surge into empty

piping shall evaluate interconnected pumps operating at run-out

flow, discharging into piping that is at atmospheric pressure;

and,

Design conditions for column separation shall consider the fluid

studied at its highest expected temperature for normal operation

– ensuring the lowest potential vapor pressure for the fluid

studied is considered in the analysis.

8. Identify anchor and nozzle movements and the number of cycles

(cold-to-hot-to cold) for any thermal case expected over design life of

the system.

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9. Identify any other load cases not considered in this procedure that

warrant analysis to fully demonstrate compliance with ASME B31.3

requirements. See ASME B31.3 para. 301.5 Dynamic Effects.

4.3.2 Identify Design Conditions for TSR AC 5.8.5 Analyses

Analyst 1. Identify the pressure/temperature conditions that shall be considered in

the TSR AC 5.8.5 analyses, including but not limited to:

Pressure sources identified per Section 4.2.1, Step 3

Elevation differences

Flow transients or surges (see Step 2)

External pressure or differential pressure for negative pressure

service

Fluid temperatures, ambient temperatures, solar radiation,

heating or cooling medium temperatures, and the applicable

provisions of ASME B31.3 paragraphs 301.3.2, 301.3.3, and

301.3.4 orA301 for nonmetallic piping; and

Operating pressure and temperature expected at maximum

metal or nonmetallic temperature conditions.

2. Identify potential flow transient initiators (i.e., triggering events) for

analyses required by TSR AC 5.8.5:

a. Examine piping system configuration and operations activities to

be performed when TSR AC 5.8.5 SAC is applicable and

identify unanticipated events (i.e. unplanned events resulting

from operator error [see Attachment D, D.1.3] or single

independent or common mode failures) that may cause changes

in fluid momentum in piping and resulting surge, valve-induced

water hammer, or elevation-induced column separation.

b. Identify unanticipated valve operation during the waste transfer

in cases where technical procedures allow or otherwise provide

for valve manipulation during conduct of the waste transfer (may

include flushing, or testing, whether manual or automatic if

performed during the waste transfer). Valve operations do not

need to consider inadvertent pump operations when the

procedure verifies that the pump is not operating before the valve

operation and therefore are not considered transient initiators.

c. Screen each valve operation identified as a triggering event for

the potential occurrence of valve-induced water hammer,

according to the screening criteria in Table 3(a).

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d. Identify cases where pressure sources (e.g., pump start, valve

opening) re-established pressure to waste transfer systems that

support a column separation condition per the screening criteria

in Table 3(b).

3. Identify the design condition (i.e., the pressure at the most severe

condition of coincident internal or external pressure and temperature

[minimum or maximum] expected during service) from Step 1,

excluding flow transients or surge, for TSR AC 5.8.5 overpressure

analyses.

4. Identify the design conditions for TSR AC 5.8.5 flow transient analyses:

a. Identify the design conditions (i.e., the pressure at the most

severe condition of coincident internal or external pressure and

temperature [minimum or maximum] expected during service)

from Step 1 where screening criteria in Table 3(a) or 3(b) show

potential flow transients require a detailed analysis.

b. For valve operations, design conditions at the time of a

triggering event shall be those that produce the maximum

expected flow through the system, considering the pressure

source and fluid characteristics examined.

c. For pump operations, design conditions for surge into empty

piping shall consider interconnect pumps operating at run-out

flow, discharging into empty piping at atmospheric pressure.

d. Design conditions for column separation shall consider the fluid

studied at its highest expected temperature for normal operation

– ensuring the lowest potential vapor pressure for the fluid

studied is considered in the analysis.

4.4 Determine Pressure and Stress Limits

The following steps identify pressure and stress limits applicable for:

ASME B31.3 analyses and

TSR AC 5.8.5 analyses.

4.4.1 Determine Pressure and Stress Allowances for ASME B31.3 Analyses

Analyst 1. Identify pressure design limits for analysis of internal pressure and

potential overpressure due to sustained and occasional loads per

Table 4(a).

2. Identify stress design limits for analysis of longitudinal stress due to

sustained and occasional loads, including seismic, flow transient, and

other dynamic effects (see ASME B31.3, para. 301.5), per Table 4(b).

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3. Identify stress design limits for pipe supports and pipe support welds

based on the structural design criteria described in Table 4(c).

4. Identify allowable displacement stress range for piping to account for

thermal effects of changes in piping temperature per Table 4(d).

5. As alternative to direct calculation, values for pressure and stress

limits for pipe, pipe supports, and support welds calculated in

RPP-CALC-54447, “Piping Structural Analysis Methodology for

Evaluation of Waterhammer,” provided the materials and conditions

considered in that analysis are valid for the piping system being

evaluated.

4.4.2 Determine Pressure and Stress Limits for TSR AC 5.8.5 Analyses

Analyst 1. Identify pressure limits for analysis of overpressure and flow transients

per Table 5(a).

2. Identify stress limits for analysis of longitudinal stress due to

overpressure and occasional loads, including seismic and flow

transients, per Table 5(b).

3. Select a method from Table 5(c) and determine the stress limits for pipe

supports and pipe support welds, if supports are credited to limit piping

stresses.

4.5 Perform Piping Stress Analysis

Analyze waste transfer system based on the inputs, assumptions, design limits, and load

conditions defined in this procedure.

Evaluation of sustained and occasional loads, including flow transients, and their effects on the

waste transfer system is a calculation-intensive process which is normally accomplished by the

use of commercially available software programs. The following software packages shall be used

to analyzing the waste transfer systems unless prior approval is obtained from the Chief Engineer

for use of alternative software:

Structural evaluation – Bentley AutoPIPE™

Input for structural analysis of flow transient – AFT Impulse™.

4.5.1 Perform ASME B31.3 Analyses

Analyst 1. Model the waste transfer system based on documented inputs and

assumptions and methods specified for approved software.

2. Perform an AFT Impulse™ flow transient analysis for the design

condition(s) identified for detailed examination in Section 4.3, and

determine peak pressure expected to result from the triggering event

considered for flow transients. This provides inputs forces and loads for

structural analysis of flow transient conditions using Bentley

AutoPIPE™.

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3. Perform the ASME B31.3 analyses based on the piping system model

and identified design conditions. (See Table 6 for methods for

analyzing seismic loads.)

4. Evaluate the results of the ASME B31.3 code case analyses.

a. If internal pressures and calculated stresses do not exceed ASME

B31.3 allowances, analysis is complete; skip step b.

b. If ASME B31.3 allowances are exceeded, mitigate or eliminate

the problematic condition(s) by one more of the following

methods in order preference: (1) redesign, (2) engineered

feature(s), and/or (3) administrative feature(s). Re-analyze

piping system accordingly.

5. If engineered and/or administrative feature(s) are used to mitigate or

eliminate the problematic condition(s) that result in exceeding

ASME B31.3 allowances, identify these features as defense-in-depth

features.

4.5.2 Perform TSR AC 5.8.5 Analyses

Analyst 1. Model the waste transfer system based on documented inputs and

assumptions and methods specified for approved software. Develop TSR

AC 5.8.5 cases for input into the model:

Overpressure

Flow Transient.

2. Perform an AFT Impulse™ flow transient analysis for the design

condition(s) identified for detailed examination in Section 4.3 and

determine peak pressure expected to result from the triggering event

considered for flow transients. This provides inputs forces and loads for

structural analysis of flow transient conditions using Bentley

AutoPIPE™.

3. Perform the TSR AC 5.8.5 analyses based on the piping system model

and identified design conditions for overpressure and flow transient

cases. See Table 6 for methods for analyzing seismic loads.

4. Evaluate the results of the TSR AC 5.8.5 analyses:

a. If the identified ASME B31.3 allowances are not exceeded,

analysis is complete; skip step b.

b. If Section III Service Level D limits or Case N-155-2 limits for

nonmetallic piping as applicable are exceeded, identify and

implement safety-significant support SSCs and/or SACs that

mitigate or eliminate the problematic condition(s).

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4.5.3 Analyze Piping Supports for ASME B31.3 Analyses

Analyst 1. Determine the governing reaction forces, and moments at supports,

anchors, and nozzles due to sustained and occasional load stresses,

including flow transients.

2. For the ASME B31.3 analyses, analyze pipe supports and support welds

per criteria in AISC “Manual of Steel Construction.”

3. Evaluate the results of the ASME B31.3 analyses:

a. If calculated stresses in pipe supports and support weld do not

exceed AISC limits and addition requirement s for nonmetallic

piping as applicable (see paragraph A321), analysis is complete;

skip step b.

b. If AISC limits are exceeded, mitigate or eliminate the

problematic condition(s) by one or more of the following

methods in order of preference: (1) redesign, (2) engineered

feature(s), and/or (3) administrative feature(s). Re-analyze pipe

supports accordingly.

4.5.4 Analyze Piping Supports for TSR AC 5.8.5 Analyses

1. Determine the governing reaction forces, and moments at supports,

anchors, and nozzles due to sustained and occasional load stresses,

including flow transients.

2. For the TSR AC 5.8.5 analyses, if required, analyze pipe supports and

support welds per the method selected in Section 4.4.2, Step 3.

3. Evaluate the results of the TSR AC 5.8.5 analyses:

If calculated stresses in pipe supports and support weld do not

exceed the limits, analysis is complete; skip step b.

If the limits are exceeded, a new method may be selected and

new limits determined per Section 4.4.2, Step 1, and the

supports and support welds re-analyzed, or the pipe supports

cannot be credited in the TSR AC 5.8.5 analyses.

4.6 Prepare and Issue Analysis Report

TFC-ENG-DESIGN-C-10 describes the process for preparing, processing, and revising a Piping

Analysis Report.

All calculations shall be checked and verified as required by TFC-ENG-DESIGN C-52 or other

governing design verification procedure.

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5.0 DEFINITIONS

ASME B31.3 Allowances. Criteria (e.g., allowable(s), allowances, criteria, design, limit(s),

maximum, minimum, rating, etc.) used to meet ASME B31.3 requirements (i.e., ASME B31.3

Code compliant), usually preceded or followed by the term “shall” in ASME B31.3 and referring

to loads, pressures, stresses, temperatures, thicknesses, etc.

New Piping. Piping systems, subsystems, and components, or modifications thereto, that are

designed, constructed, and examined after issuance of this procedure.

Piping. Assemblies of piping components used to convey, distribute, mix, separate, discharge,

meter, control, or snub fluid flows. Piping also includes pipe-supporting elements, but does not

include support structures, such as building frames, bents, foundations, or any equipment

excluded from the scope of the ASME B31.3 Code.

Piping Components. Mechanical elements suitable for joining or assembly into pressure-tight

fluid-containing piping systems. Components include pipe, tubing, fittings, flanges, gaskets,

bolting, valves, and devices such as expansion joints, flexible joints, pressure hoses, traps,

strainers, inline portions of instruments, and separators.

Piping Subassembly. A portion of a piping system that consists of one or more piping

components.

Piping System. Interconnected piping subject to the same set or sets of design conditions.

6.0 RECORDS

The following records are generated during the performance of this procedure:

Engineering calculations per TFC-ENG-DESIGN-C-10 or other governing engineering

calculation procedure.

The record custodian identified in the Company Level Records Inventory and Disposition

Schedule (RIDS) is responsible for record retention in accordance with

TFC-BSM-IRM_DC-C-02.

7.0 SOURCES

7.1 Requirements

1. HNF-WM-SD-TSR-006, “Tank Farms Technical Safety Requirements.”

2. RPP-13033, “Tank Farms Documented Safety Analysis.”

3. TFC-ENG-STD-22, “Piping, Jumpers, and Valves.”

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7.2 References

1. AISC, Manual of Steel Construction.

2. ANSI/API Standard 521, 5th Edition, January 2007 (including Errata June 2007),

Addendum May 2008, “Pressure-relieving and Depressuring Systems,” American

Petroleum Institute, Washington, D.C.

3. ASCE 7, “Minimum Design Loads for Buildings and Other Structures.”

4. ASME B31.1, “Power Piping,” American Society of Mechanical Engineers, New York,

New York.

5. ASME B31.3, Process Piping, American Society of Mechanical Engineers, New York,

New York.

6. ASME B31.9, “Building Services Piping,” American Society of Mechanical Engineers,

New York, New York.

7. ASME Boiler and Pressure Vessel Code Section III, Division 1, American Society of

Mechanical Engineers, New York, New York.

8. ASME Boiler and Pressure Vessel Code Section VIII, American Society of Mechanical

Engineers, New York, New York.

9. ARH-ST-133, “Vapor-Liquid-Solid Phase Equilibria of Radioactive Sodium Salt Wastes

at Hanford.”

10. Crane TP-410, Flow of Fluids through Pipes, Valves, and Fittings.

11. Moody, F.J., Introduction to Unsteady Thermofluid Mechanics, John Wiley & Sons,

1990.

12. NISTIR 5078, Thermodynamic Properties of Water, October 1998.

13. RPP-14859, “Specification for Hose-in-Hose Transfer Line and Hose Jumpers.”

14. RPP-22668, “River Bend Transfer Systems Hose Roughness Calculation.”

15. RPP-CALC-23897, “VFD Driven Induction Motor/Pump Performance Evaluation.”

16. RPP-CALC-54447, “Piping Structural Analysis Methodology for Evaluation of

Waterhammer.”

17. RPP-RPT-27570, “Development of PC2 Surface Spectra for Double-Shell Tank Facilities

18. RPP-RPT-50042, “Bulk Modulus and Sonic Velocity Estimates for Double-Shell Tank

Supernatants.”

19. RPP-RPT-52248, “Fitness for Service Program Requirements.”

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20. RPP-RPT-54884, “Review of 2” Safe-T-Chem Hose Waterhammer Testing

21. RPP-RPT-54492, “Single-Shell Tank Sluicer Piping Drainability Assessment.”

22. RPP-RPT-54581, “Supplemental Basis Document for Waterhammer Calculations.”

23. RPP-RPT-58773, “Assessment of Safety Significant Piping Jumpers to Assure Excess

Load Capacity for Potential Water Hammer (Leak Check and Flush) Events.”

24. TFC-BSM-IRM_DC-C-02, “Records Management.”

25. TFC-ENG-DESIGN-C-10, “Engineering Calculations.”

26. TFC-ENG-DESIGN-C-52, “Technical Reviews.”

27. TFC ENG FACSUP-C-03, “Technical Evaluations.”

28. TFC-ENG-STD-02, “Environmental/Seasonal Requirements for TOC Systems,

Structures, and Components.”

29. TFC-ENG-STD-06, “Design Loads for Tank Farm Facilities.”

30. TFC-ENG-STD-21, “Hose-in-Hose Transfer Lines.”

31. TFC-ENG-STD-25, “Transfer Pumps.”

32. TFC-PLN-03, “Engineering Program Management Plan.”

33. WHC-SD-W236A-DA-002, “Stress Analysis of Integral Seal Block (ISB) Jumper

Connectors,” 1995, Westinghouse Hanford Company.

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Table 1. Inputs for Piping Analyses.

Table 1(a). General Inputs for ASME B31.3 and TSR AC 5.8.5 Analyses

Item Description of Typical Input

1. Pipe material and dimensional specifications, including:

ASTM or API specification, type, grade, and method of manufacture; dimensional standard listed in

ASME B31.3 Table 326.1 or Table A326.1 as applicable

Nominal pipe size and wall thickness, and mill tolerance

Weld Joint Quality Factor, Ej or Ec, attributable to the method of manufacture per ASME B31.3

paragraph 302.3.4 for other than seamless pipe

If non-metallic pipe or non-ASTM or non-API material is used, include the pipe manufacturer catalog

sheets with material properties in Appendix E of the piping analysis.

2. Pipe fitting material and dimensional specifications, including:

Fitting and joint type – including flanges, elbows, tees, reducers, and unions; ASTM material

specification, type, and grade

Nominal pipe size and pressure class, dimensional standard listed in ASME B31.3 Table 326.1

State if there are unlisted or otherwise non-standard fittings used in the piping analysis.

3. Valve and piping component details and specifications, including:

Component type, governing specification listed in ASME B31.3, Table 326.1 or Table A326.1 as

applicable; material specification, type, and grade

Nominal pipe size; pressure class or rating, limiting conditions of temperature

State if there are unlisted components used in piping; for unlisted components, state qualification basis

under the terms of ASME B31.3, paragraph 302.2.3.

Provide valve and other component data sheets in the piping analysis report, including component length

and weight. For valves with heavy operators that are to be modeled as an eccentric weight, state valve

operator size, weight, length, and offset of the center of gravity.

4. Bolting material specification (if bolting is used in design), including material type and grade

5. Insulation thickness and density (if used in design)

6. Corrosion-erosion allowance and expected service life

For austenitic stainless steel piping and carbon steel piping, the corrosion-erosion allowance is

determined in accordance with requirements in TFC-ENG-STD-22 for the expected service life of the

system.

For unlisted piping components compliant with TFC-ENG-STD-21, “Hose in Hose Transfer Lines”

and TFC-ENG-STD-22 (i.e., HIHTLs and synthetic rubber hose jumpers), the corrosion-erosion

allowance used for pressure design may be neglected. Service life of these components is determined

by requirements in RPP-14859, “Specification for Hose-in-Hose Transfer Line and Hose Jumpers”.

7. Specific gravity of fluids confined by piping, including bounding value for evaluation of limiting

conditions

8. Properties for flexibility analysis:

Thermal expansion and modulus of elasticity attributable to piping material per ASME B31.3,

Appendix C

Piping temperature during field installation, if known.

Pipe support friction (required per ASME B31.3, paragraph 319.4.3)

Flexibility analysis for nonmetallic piping shall meet ASME B31.3 paragraph A319.

9. Environmental conditions to which piping is subjected, per TFC-ENG-STD-02, “Environmental/Seasonal

Requirements for TOC Systems, Structures, and Components” for the performance category assigned to

piping and supports

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Table 1. Inputs for Piping Analyses. (cont.)

Table 1(b). Inputs for ASME B31.3 Seismic Analyses


1. For static analysis:

TFC-ENG-STD-06, “Design Loads for Tank Farm Facilities” static load parameters SDS and IP shall be

identified in the piping analysis report;

ASCE-7, “Minimum Design Loads for Buildings and Other Structures” static load parameters aP, RP,

and z/h shall be determined by the analyst, with justification documented in Appendix G of the piping

analysis report.

2. For dynamic modal analysis, the applicable input in-structure seismic response spectra shall be per PC2

spectra defined in RPP-RPT-27570, “Development of PC2 Surface Spectra for Double-Shell Tank

Facilities,” where :

SDS = 0.588, SDI = 0.192

the design response spectrum curve should be scaled-up by the factor, FE where FE = IP KE / RP, and:

Ip = importance factor to be assigned by the Project

Rp = response modification factor for piping systems, based on ASCE-7 but not to exceed 3.

KE = (1 + 2 z/h) where z = maximum elevation with respect to grade of pipe support attachment to

building and h = average roof elevation with respect to grade

Amplification due to piping flexibility, ap, equals 2.5

The analyst may choose to input the referenced spectra and then scale the resulting values by the ratio of

the 90% participating mass summation in the direction of loading with the minimum horizontal load

requirement of ASCE 7, Eqn 13.3-2 or Eqn 13.3-3.

3. For all analyses of the occasional load of seismic motion, the reference for anchor motions should be

provided, if available, or the calculation of anchor motions should be documented in Appendix I of the

report if they are calculated by the analyst.

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Table 1. Inputs for Piping Analyses. (cont.)

Table 1(c). Inputs for ASME B31.3 and TSR AC 5.8.5 Analyses of Flow Transient


1. For hand calculations of screening criteria or simple configurations, a bounding value for speed of sound in

piping shall be determined using the following fluid properties or other properties attributable to the

specific fluid evaluated:

For liquids, per Attachment B, Table B-1, for the specific gravity of the fluid considered, as corrected

to account for temperature: add or subtract the difference between sound speed for water in Table B-2

at the temperature evaluated and the value for 30 deg C.

For water, the speed of sound shall be based on NISTIR 5078, “Thermodynamic Properties of Water,”

October 1998, or ASME Steam Tables

For slurry, the effects of solids on sound speed in metallic piping shall be accounted for per Attachment B,

Eqn. B-2 (ref. RPP-RPT-50042, “Bulk Modulus and Sonic Velocity Estimates for Double-Shell Tank

Supernatants”).

2 The speed of sound for non-rigid piping comprised of HIHTLs or hose jumpers compliant with RPP-14859

and within the restrictions of RPP-RPT-54884 is 1,892 ft/sec. (Ref. RPP-RPT-54884, “Review of 2” Safe-

T-Chem Hose Waterhammer Testing”)

3. For determining system flow:

Losses through valves shall be based on valve flow coefficient (Cv) tables or characteristics of valve

type (i.e., linear, equal percentage, or quick opening)

Friction factors for HIHTL material and hose-based jumpers shall be based on the results in RPP-

22668, “River Bend Transfer Systems Hose Roughness Calculation.”

4. Design features for elevation control (such as air vents, vacuum breaks, or passive siphon breaks) that are

creditable based on documented failure modes analyses of such features.

5. Point of flush or test water introduction, if provided, and direction(s) of flow for flush water or test water.

Table 1(d). Specific Inputs for ASME B31.3 and TSR AC 5.8.5 Analyses


FOR ASME B31.3 PIPING ANALYSES:

1. Stress Intensification and Flexibility Factors (SIF) for elbows and welding tees shall be calculated per

ASME B31.3, Appendix D. For non-standard fittings, indicate the SIF used, the technical basis, and

reference for same. ASME paragraph 319.4 may be applicable for nonmetallic piping (See paragraph

A319.4.2). Determine SIF for use with nonmetallic piping per ASME Boiler and Pressure Vessel Code

Case N-155-2 -3673.

FOR TSR AC 5.8.5 ANALYSES:

2. Equations for SIF in Section III, Division 1, paragraph ND-3600 shall be utilized, or Section III SIFs may

be used with hand calculations that convert moments from an ASME B31.3 analysis to Section III results.

For non-standard fittings, indicate the SIF used, the technical basis, and reference for same.

Determine SIF for use with nonmetallic piping per ASME Boiler and Pressure Vessel Code Case N-155-2

-3673.

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Table 2. Assumptions for Piping Analyses.

Table 2(a). General Assumptions for ASME B31.3 and TSR AC 5.8.5 Analyses

Item Description of Typical Assumption

1. Flexible metallic and non-metallic hoses and HIHTLs that are qualified as unlisted components per

ASME B31.3, installed in accordance with manufacturer’s instructions, and operated within their rated

design conditions, are adequate to resist longitudinal forces acting on them and effectively isolate

longitudinal stress due to axial forces, bending moments, and torsion between rigid piping structures.

Basis: Flexible nature of hose materials, qualification status as an unlisted piping component.

2. If temperature of piping at time of installation is unknown, analysis shall employ values of thermal

displacement that are based on the following metal temperatures at time of installation:

80° F, when considering the thermal displacement at minimum metal temperature.

60° F, when considering the thermal displacement at maximum metal temperature.

Basis: Reasonably conservative estimate for thermal flexibility analysis.

Table 2(b). Assumptions for ASME B31.3 Seismic Analyses


1. For static analyses of the occasional load of seismic motion:

the EW and NS spectra are assumed as equal, unless otherwise specified by seismic design criteria;

the vertical spectra are assumed as 0.2 SDS, unless otherwise specified by seismic design criteria.

Basis: TFC-ENG-STD-06

2. Anchor motions below 1/8 inch may be ignored.

Basis: Equivalent to typical pipe-to-support gaps

3. For modal analyses, PUREX connectors at the connector/nozzle interface shall be modeled using the

following stiffness factors:

Connector

Size

Kux (lbf/in) Kuy (lbf/in) Kuz (lbf/in) Krotx (lbf-

in/rad)

Kroty (lbf-

in/rad)

Krotz (lbf-

in/rad)

2-Inch 1.35e+7 2.78e+4 2.78e+4 7.38e+4 4.53e+5 4.53e+5

3-Inch 1.90e+7 2.47e+4 2.47e+4 1.02e+5 9.16e+5 9.16e+5

4-Inch 2.33e+7 2.52e+4 2.52e+4 2.09e+5 1.43e+6 1.43e+6 Reference WHC-SD-W236A-DA-002 Table 3.5, Connector Stiffnesses to Piping Reaction Loads and Figure 1

Coordinate System for more details.

Basis: WHC-SD-W236A-DA-002

4. There are no structures with performance category classifications that allow them to fail under the effects

of seismic motion in a manner that may damage safety significant piping.

Basis: TFC-ENG-STD-06

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Table 2. Assumptions for Piping Analyses. (cont.)

Table 2(c). Assumptions for B31.3 and TSR AC 5.8.5 Analyses of Flow Transient


1. For computing system flow:

Computations of pressure loss through PUREX connectors shall treat such connectors as 90-degree

miter bends.

Basis: Comparison of PUREX connector details with typical 90-degree miter bend designs

Simplified computations that determine bounding values for steady state system flow may be

performed using the hand calculation methods described in Crane TP-410, “Flow of Fluids through

Pipes, Valves, and Fittings,” where friction factors for steel pipe are as specified for fully turbulent

flow.

Basis: Crane TP-410, conservatism

2. For determining flow transient loads due to surge:

In absence of other verifiable basis, the ramp-up time for variable- and constant-speed pumps from full

stop to the target operating speed shall be assumed to be instantaneous. Instantaneous is considered

< 0.1 seconds when a discrete time is required by software.

Basis: Conservatism

3. For determining operating time of manual or automatically actuated valves:

Operating duration of manually operated valves fitted with a direct operating lever or handle shall be

assumed to be instantaneous, unless other basis is specified, or unless valve operation is controlled by a

safety-significant SSC or SAC under the procedural controls governing Tank Farms administration,

engineering, and operation.

Basis: Conservatism

Operating duration of automatically actuated valves shall be assumed to be the actual valve operating

time observed for opening or closing during acceptance or operational testing, unless the operator has a

failure mode that may result in faster closure. In such an event, the fastest credible valve closing time

associated with failure shall be used.

Basis: Ensures representative conditions are analyzed

4. For determining the disturbance time used to analyze valve operations:

Disturbance time for valve closure shall be the operating time required to reduce system flow from

80% of maximum steady-state flow to zero

Basis: Reasonable conservative estimate that ensures the installed characteristics of pressure drop versus

flow through valves being operated in the piping system are modeled:

5. For determining the hydraulic conditions used to analyze potential column separation events:

Passive design features that vent waste transfer piping (e.g., open siphon breaks or recirculation

branches leading back to a tank) may be credited in determining the maximum pressure in piping,

provided there are no credible failure mechanisms (e.g., plugging or submergence) that may render

such features inoperable.

Basis: As specified in a documented evaluation of potential failure modes and effects on operability.

The elevation of the location at which the liquid column reaches the maximum velocity is

conservatively assumed to be where the void pocket extends.

Basis: Conservatism

The vapor pressure of waste can be conservatively modeled as the vapor pressure of water if additional

data is not available. However, if data exists to show that for a given route the vapor pressure is

higher, such data may be used.

Basis: ARH-ST-133, “Vapor-Liquid-Solid Phase Equilibria of Radioactive Sodium Salt Wastes at

Hanford,” ASME Steam Tables

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Table 3. Screening Criteria.

Table 3(a). Screening Criteria for Valve Operation Transient

1. Compute

propagation time, tp Compute propagation time according to the formula: 𝑡𝑝 =

2𝐿

𝐶𝑓𝑝 where:

𝐿 = Distance from valve to tank, pump, or reservoir.

Cfp = Speed of sound associated with the fluid retained in the piping system; or

adjusted to account for the effects of non-rigid pipe or tube (see Attachment B).

2. Determine

disturbance time, tdi

For valves assumed to act instantaneously, td= 0.

For valves where closure time is definable (see inputs), determine disturbance time

according to the installed flow characteristics of the valve:

Identify the valve position (in terms of percent open) at which system flow is reduced to

80% of maximum flow.

td = time required to close the valve from this position, as a fraction of the overall closure

time identified in input data.

3. Screen disturbance

time for potential flow

transient

Where td is more than 10 x tp, no further analyses of flow transient effects for this

triggering event are required.

Where td is less than or equal to 10 x tp, a detailed analysis of the flow transient shall

be performed per this procedure.

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Table 3. Screening Criteria. (cont.)

Table 3(b). Screening Criteria for Column Separation Transient

1. Examine piping

system

Examine the piping system layout as identified in inputs:

Identify changes in elevation along the route, elevation controls for inspirating or

aspirating piping, presence of check valves, and attributes of discharge point, including

potential for submergence.

2. Screen for self-

draining piping

The waste transfer system is considered drained if there are no standing columns

(i.e., filled pipe) and not that the waste transfer system is completely drained of fluid. Free

draining is the process that leaves the waste transfer system drained.

For waste transfer systems that allow free draining to source and discharge points, this

mitigates the potential for column separation to occur. [e.g.: Piping systems that

incorporate qualified passive siphon breaks at or near hydraulic high points (see inputs and

assumptions)] No further analyses of flow transient associated with column separation are

required for these systems.

Engineered and/or administrative feature(s) (e.g., vacuum breakers, valve manipulation to

vent or drain) can be credited for the ASME B31.3 analyses and shall be identified as

defense-in-depth (DID Feature 29) and the system can be considered free draining for the

ASME B31.3 analyses. (Note: Engineered features are not required to be identified as

defense-in-depth features if there are no credible failure modes that prevent the credited

function as documented [or referenced] in the evaluation.).

Engineered and/or administrative feature(s) (e.g., vacuum breakers, valve manipulation to

vent or drain) can be credited for the TSR AC 5.8.5 analyses and shall be identified as

safety-significant support SSCs or TSR SACs. (Note: Engineered features are not

required to be identified as safety-significant if there are no credible failure modes that

prevent the credited function as documented [or referenced] in the evaluation.).

In cases where the discharge point is not submerged under any planned operating

conditions or single-mode failures, and where there are no obstructions or area reductions

at the discharge point that may accumulate material, the piping may be assumed to drain

freely from its nearest interconnected hydraulic high point, provided the internal diameter

at the discharge point is equal to or greater than that specified by the method defined in

RPP-RPT-54492, “Single-Shell Tank Sluicer Piping Drainability Assessment”.

3. Determining

column height criteria

and screening waste

transfer system

Determine the fluid column height (screening criteria, see Attachment C for example) that

can be supported by a vacuum equal to the vapor pressure of fluid being analyzed. This

height is then used to screen the waste transfer system under analysis. If the waste transfer

system does not have a column of fluid greater than or equal to the screen height, no

further analyses of flow transient associated with column separation are required for these

systems.

In cases where standing column heights are equal to or greater than the screening

criteria, column separation is credible and a detailed analysis of the potential flow

transient shall be performed per this procedure.

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Table 4. Pressure and Stress Allowances for ASME B31.3 Analyses.

Table 4(a). Internal Pressure Allowances for ASME B31.3 Analyses

Basic requirement: Stress in piping due to internal pressure including anticipated flow transient that may occur

during waste transfer, flushing, or test operations, shall not exceed the basic allowable stress provided for in

ASME B31.3, Table A-1 and related Code requirements and allowances.

Acceptance criteria: Internal pressure in piping due to sustained or occasional loads shall be considered safe when

it is less than the Design Pressure (𝑃𝐵31.3 𝐷𝑒𝑠𝑖𝑔𝑛) of piping and components, including any variation in pressure

allowable under the terms of ASME B31.3, paragraph 302.2.4. Allowances for variations of pressure or

temperature, or both, above design conditions are not permitted for nonmetallic piping per ASME B31.3, Chapter

VII, paragraph A302.2.4.

Item Criteria

1. Design Pressure 𝑃𝐵31.3 𝐷𝑒𝑠𝑖𝑔𝑛(ASME B31.3 Section 304)

For straight pipe determine the required pipe minimum wall thickness (account for mill tolerance,

corrosion allowance, threading), per ASME B31.3, para. 304.1,

For pipe bends determine the required pipe minimum wall thickness after bending, per ASME B31.3,

para. 304.2.

For listed components (including valves), per their qualified internal pressure rating or other limit

determined by their specified pressure class.

For listed components with no established rating (e.g. fittings per ASME B16.9 or B16.11), equivalent

to straight seamless pipe of the same dimensions, with wall thickness 87.5% of nominal. See ASME

B31.3, paragraph 302.2.2.

For unlisted components, per their qualified internal pressure rating.

2. Variations in pressure are allowable for internal pressures up to 20% over the pressure rating or the

allowable stress for pressure design at the temperature, provided the limitations specified in ASME B31.3,

paragraph 302.2.4 are met. Variations up to 33% are allowable if these limitations are met and owner’s

approval is provided.

3. Design Pressure 𝑃𝐵31.3 𝐷𝑒𝑠𝑖𝑔𝑛 for nonmetallic piping (ASME B31.3 Section A304)


corrosion allowance, threading), per ASME B31.3, para. A304.1,


para. A304.2.



For listed components with no established rating ASME B31.3, paragraph A302.2.2 shall be met.


4. Allowances for variations of pressure or temperature, or both, above design conditions are not

permitted for nonmetallic piping. See ASME B31.3, Chapter VII, paragraph A302.2.4.

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Table 4. Pressure and Stress Allowances for ASME B31.3 Analyses. (cont.)

Table 4(b). Stress Allowances for ASME B31.3 Analyses

Basic requirement: Longitudinal stress in piping (SL) due to sustained or occasional loads, including anticipated

flow transient occurring during waste transfer, shall not exceed the basic allowable stress provided for in

ASME B31.3, Table A-1, and related Code requirements and allowances.

Acceptance criteria: Longitudinal stresses in piping shall be considered safe when calculated stresses are less than

or equal to allowances established by the following criteria:

Item Criteria

1. Longitudinal stress SL in piping due to sustained loads shall not exceed the basic allowable stress at the

maximum metal temperature condition (Sh) provided for in ASME B31.3, Table A-1, and related Code

requirements and allowances, when computed according to ASME B31.3, eq. 23a. (see ASME B31.3 para.

302.3.5(c), Stresses Due to Sustained Loads, SL)

2. Longitudinal stress in piping SL due to occasional loads such as seismic, or anticipated flow transient loads

occurring during waste transfers shall not exceed 1.33 times the basic allowable stress at the maximum

metal temperature condition provided for in ASME B31.3, Table A-1, when computed according to ASME

B31.3, eq. 23a. (see ASME B31.3 para. 302.3.6, Limits of Calculated Stresses Due to Occasional Loads,

for additional limitations)

3. Stresses due to sustained loads for nonmetallic piping shall meet the requirements of ASME B31.3

paragraph A302.3.3.

4. Stresses due to occasional loads for nonmetallic piping shall meet the requirements of ASME B31.3

paragraph A302.3.4.

Table 4(c). Stress Allowances for Piping Supports in ASME B31.3 Analyses

Basic requirement: Maximum working stress in pipe supports and support welds resulting from waste transfer,

flush, and test operations shall not cause failure of the piping system.

Acceptance criteria: Structural design of piping supports shall be considered adequate provided the following

criteria are satisfied:

Item Criteria

1. For analyses of sustained and occasional loads, design criteria for piping supports shall be per AISC Steel

Construction Manual.

Table 4(d). Allowable Stress Range for ASME B31.3 Thermal Flexibility Analyses

Basic requirement: Piping systems shall have sufficient flexibility to prevent thermal expansion or contraction or

movements of piping supports and terminals from causing failure, leakage at joints, detrimental stresses or

distortion in piping and valves or in connected equipment.

Acceptance criteria: Thermal flexibility of piping shall be considered adequate when the criteria in ASME B31.3,

Section 319 (Section A319 for nonmetallic piping) are satisfied.

Item Criteria

1. The calculated displacement stress range, SE, shall not exceed the allowable stress range, SA, determined

per ASME B31.3, eq. 1a or 1b, independent of longitudinal stress.

2. Reaction forces shall not be detrimental to supports or connected equipment.

3. Nonmetallic piping shall meet the requirements of ASME B31.3 Section A319.

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Table 5. Pressure and Stress Limits for TSR AC 5.8.5 Analyses.

Table 5(a). Internal Pressure Limits for TSR AC 5.8.5 Analyses.

Basic requirement: Internal pressure in waste transfer piping due to sustained overpressure or unanticipated flow

transient during waste transfer shall not exceed the limits specified in ASME B&PV Code Section III, Division 1,

Subsection ND for Service Level D. Internal pressure in waste transfer piping due to sustained overpressure or

unanticipated flow transient during waste transfer in nonmetallic piping shall not exceed the limits specified in

ASME B&PV Code Case N-155-2 for nonmetallic piping meeting the requirements as specified in the Reply on

page 1 of the Case N-155-2 or the limits of ASME B31.3 Chapter VII if the requirements in the Reply are not met.

Acceptance criteria: Stresses due to overpressure or unanticipated flow transient in piping shall be within

TSR AC 5.8.5 failure limits when the internal pressure is less than or equal to limits established by the following

criteria (Items 1-3 for piping and Items 4-6 for nonmetallic piping):

Item Criteria

1. Determine the internal pressure capacity 𝑃𝑎

For straight pipe, the pressure Pa is calculated in accordance with ASME B&PV Section III, Division 1,

Subsection ND eq. ND-3641.1(5). (see ND-3641.1 Straight Pipe Under Internal Pressure.)

For pipe bends, account for wall thinning due to bend (see ND-3642.1 Pipe Bends)




to straight seamless pipe of the same dimensions, with wall thickness 87.5% of nominal.


2. TSR AC 5.8.5 overpressure failure limits are the criteria for Service Level D in ASME B&PV Section III

Division 1, Subsection ND:

For listed pipe, fittings, and bends, or unlisted piping components other than valves, per Section III,

paragraph ND-3650:

𝑃 ≤ 2𝑃𝑎

For valves, per Section III, paragraph ND-3520:

𝑃 ≤ 1.5𝑃𝑎

Where

𝑃 = pressure identified in Section 4.3.2, Step 3,

𝑃𝑎 = pressure capacity of the pipe and piping components as determined Item 1 above.

3. TSR AC 5.8.5 fluid transient failure limits are the criteria for Service Level D in ASME B&PV Section III

Division 1, Subsection ND:

For listed pipe, fittings, and bends, or unlisted piping components other than valves, per Section III,

paragraph ND-3650:

𝑃0 + 𝛥𝑃 ≤ 2𝑃𝑎

For valves, per Section III, paragraph ND-3520:

𝑃0 + 𝛥𝑃 ≤ 1.5𝑃𝑎

Where

𝑃𝑂 = design pressure,

ΔP = additional pressure due to unmitigated operation or flow transient

𝑃𝑎 = pressure capacity of the pipe and piping components as determined Item 1 above.

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Table 5. Pressure and Stress Limits for TSR AC 5.8.5 Analyses. (cont.)

4. Determine the internal pressure capacity P for nonmetallic piping

ASME B&PV Code Case N-155-2

For straight pipe, the pressure P is the lesser value calculated in accordance with ASME B&PV Code

Case N-155-2 eq. -3641.1(2) and (4). (see -3641.1 Straight Pipe Under Internal Pressure.)

For pipe bends, account for wall thinning due to bend (see ND-3642.1 Pipe Bends)




to straight seamless pipe of the same dimensions, with wall thickness 87.5% of nominal.


ASME B31.3 Determine Design Pressure/Pressure rating P


corrosion allowance, threading), per ASME B31.3, para. A304.1,


para. A304.2.



For listed components with no established rating ASME B31.3, paragraph A302.2.2 shall be met.


5. TSR AC 5.8.5 overpressure failure limits are:

ASME B&PV Code Case N-155-2 criteria for Service Level D:

For listed pipe, fittings, and bends, or unlisted piping components other than valves -3611.2(c)(4):

𝑆 =𝑃𝑚𝑎𝑥𝐷𝑜

2(𝑡𝑚𝑐−𝐵) [derived from -3641.1 Equation (2)]

𝑆 ≤ 1.8𝑆𝐴𝐶𝑃 (SACP from Table -3611-1)

For valves, per Section III, paragraph ND-3520 [see Case N-155-2, Reply (c) page 1]:

𝑃𝑚𝑎𝑥 ≤ 1.5𝑃

ASME B31.3

𝑃𝑚𝑎𝑥 ≤ 𝑃

Where

𝑃𝑚𝑎𝑥 = pressure identified in Section 4.3.2, Step 3,

P = pressure capacity of the pipe and piping components as determined Item 4 above.

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6. TSR AC 5.8.5 fluid transient failure limits are

ASME B&PV Code Case N-155-2 criteria for Service Level D:

For listed pipe, fittings, and bends, or unlisted piping components other than valves [-3611.2(c)(4)]:

𝑆 =(𝑃0+𝛥𝑃)𝐷𝑜

2(𝑡𝑚𝑐−𝐵) [derived from -3641.1 Equation (2)]

𝑆 ≤ 1.8𝑆𝐴𝐶𝑃 (SACP from Table -3611-1)

For valves, per Section III, paragraph ND-3520 [see Case N-155-2, Reply © page 1]:

𝑃0 + 𝛥𝑃 ≤ 1.5𝑃

ASME B31.3

𝑃0 + 𝛥𝑃 ≤ 𝑃

Where

𝑃𝑂 = design pressure,

ΔP = additional pressure due to unmitigated operation or flow transient

P = pressure capacity of the pipe and piping components as determined Item 4 above.

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Table 5(b). Stress Limits for TSR AC 5.8.5 Analyses

Basic requirement: Longitudinal stress in piping due to potential overpressure and due to anticipated or

unanticipated flow transient resulting from waste transfer shall not exceed the limits specified in ASME B&PV

Section III, Division 1, paragraph ND-3655 for Service Level D. Longitudinal stress in piping due to potential

overpressure and due to anticipated or unanticipated flow transient resulting from waste transfer in nonmetallic

piping shall not exceed the limits specified in ASME B&PV Code Case N-155-2 for nonmetallic piping meeting

the requirements as specified in the Reply on page 1 of the Case N-155-2 or the limits of ASME B31.3 Chapter

VII if the requirements in the Reply are not met.

Acceptance criteria: Longitudinal stresses in piping due to potential overpressure or flow transient shall be within

TSR AC 5.8.5 failure limits when calculated stresses are less than or equal to limits established by the following

criteria (Item 1 for piping and Item 2 for nonmetallic piping):

Item Criteria

1. TSR AC 5.8.5 failure limits are the criteria for Service Level D in ASME B&PV Section III, paragraph

ND-3655: SL (ND−3650) ≤ min(3Sh, 2Sy), where:

𝑆𝐿 (𝑁𝐷−3650) is computed according to the formula in Section III,

Sh is the material allowable stress at temperature consistent with the loading under consideration, and

Sy is the material yield strength at temperature consistent with the loading under consideration.

2. TSR AC 5.8.5 failure limits are

ASME B&PV Code Case N-155-2 criteria for Service Level D [-3611.2(c)(4)] :

The sum of the longitudinal stresses produced by internal pressure, thermal expansion, live and dead load,

and those produced by occasional loads identified in the Design Specifications as acting during the Service

Loadings [NCA-2142(a)] for which these limits are designated shall not exceed 1.8 times the allowable

longitudinal stress SALP in Table -3611-1. This requirement is satisfied by meeting eq. -3652.2(9), using a

stress limit of 1.8𝑆𝐴𝐿𝑃 in lieu of1.2𝑆𝐴𝐿𝑃.

ASME B31.3:

Requirements of A302.3.4 Limits of Calculated Stresses Due to Occasional Loads

Table 5(c). Stress Limits for Piping Supports in TSR AC 5.8.5 Analyses

Basic requirement: Stress in pipe supports and support welds due to sustained overpressure or unanticipated

hydraulic transients resulting from waste transfer, flush, and test operations that are credited to limit piping

stresses, shall not exceed the limits of the selected method below.

Item Criteria

1. Pipe supports stress limits shall be determined by one of the following methods:

ASME B31.3,

American Institute of Steel Construction (AISC) Manual of Steel Construction,

ASME Section III Subsection NF, using the Level D allowable stresses,

AISC N-690 or

ASME III, Appendix F.

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Table 6. Methods for Analyzing Seismic Loads.

Methods for Seismic Analysis:

1. As an option, the stress amplitude from seismic anchor motion may be excluded from the occasional stress

combination, provided it is added to the thermal expansion stress range SE and compared to the allowable stress SA.

2. Seismic anchor motions are typically applied at terminal anchors, such as equipment nozzles

3. The analyst may analyze the piping system using static or modal response spectra analysis to determine

additional loading due to seismic motion, as specified requirements for the waste transfer piping analyzed.

For Static Analysis of seismic motion:

4. The directional combination of acceleration may be the maximum (EW + vertical) and (NS + vertical); or by

combining the three directions (EW, NS, and vertical) using Square Root of Sum of Squares method.

For Modal Spectra Response Analysis of Seismic Motion:

5. Spectra input to model:

The spectra (frequency-acceleration or period-acceleration) shall be entered to the same degree of refinement

and same interpolation method for frequencies and accelerations as provided in specifications defining seismic

motion for the performance class assigned to the piping analyzed.

If the spectra input into the model are not identical to those supplied specified in requirements, the entered spectra

shall be plotted against the spectra defined in requirements to document that they either match or envelope the

specified spectra.

6. Modes shall be combined by Square Root of Sum of Squares method.

7. The analysis shall apply the 10% closely spaced mode penalty correction.

8. The response spectra analysis should have a cut-off frequency in the rigid range of the input spectra, but not

less than 33 Hz.

9. The dynamic analysis should include the rigid range correction to account for modes beyond the cut-off

frequency.

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ATTACHMENT A - FORMAT AND CONTENT OF PIPING ANALYSES

Waste transfer system piping analyses shall include the content as specified in TFC-ENG-DESIGN-C-10,

Attachment A as well as include the following appendices:

Appendix A – Marked-Up P&ID

Highlighted P&ID: color highlighted P&ID of the in-scope piping indicating continuation

points from sheet to sheet

Appendix B – Piping and Support Configuration Design

Plan, elevation and/or isometric views of the in-scope piping and supports indicating

continuation points from sheet to sheet

Include field data, transmittals, photographs, surveys, etc. that supplement the information in

piping and support configuration designs

Appendix C – Model Isometrics

Include computer-generated plots of model sections with node numbers.

For large models, include a general view plot and then plots of parts of the models.

Appendix D – Model Input-Output

Include a full input-output.

This input-output printout, numbered D-1 through D-last page will be referenced throughout

the calculation, when referring input or output.

Appendix E – Pipe and Insulation Specifications

Provide catalog sheets for non-standard sizes, provide catalog specification for insulation and

jackets showing linear weight

Appendix F – Valve and Non-Standard Components:

Include manufacturer reference information (catalog pages with relevant dimensions,

shapes, etc.);

Provide valve data sheets showing valve length and weight, and operator size, weight, length,

and offset of the center of gravity if there is a heavy operator to be modeled as an eccentric

weight.

Provide manufacturer catalog pages showing properties used (such as valve length, thickness,

weight, operator center of gravity, etc.).

For non-standard fittings also include the reference documents for SIFs and flexibility factors

Appendix G – Load Input

This Appendix will typically compile the basis for non-standard input such as input for loads

calculated or obtained by the analyst, such as thermal anchor motions, seismic (inertia and

waterhammer), waterhammer, snow and ice loads, wind loads, etc.

The seismic input should provide reference for the parameters used to develop the vertical

and lateral seismic load, or the response spectra for the NS, EW, and vertical directions, and

the anchor motions

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ATTACHMENT A – FORMAT AND CONTENT OF PIPING ANALYSES (cont.)

Appendix H – Pipe Supports

Report pertinent information on pipe supports: Input, modeling, and output for qualification,

or reference the applicable parts of Appendix B.

If supports are analyzed and qualified as part of the calculation, include supports calculations

in this Appendix

Appendix I – Equipment Interface

State reference for thermal, seismic, and settlement movements at terminal anchors or nozzles

(with reference).

Report pertinent information on equipment nozzles and building penetrations: Input,

modeling, and output loads and movements for qualification

Appendix J – Other Information

This Appendix is at the discretion of the analyst, and may include correspondence not

captured in the other Appendices

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ATTACHMENT B - SPEED OF SOUND DATA

Table B-1. Speed of Sound in Liquid at Selected Specific Gravities*

Property Units 1.1 Sg 1.2 Sg 1.3Sg 1.4 Sg Reference

c ft/s 5462 5970 6512 6872 RPP-RPT-50042

* Refer to RPP-RPT-50042 for guidance on values outside the Specific Gravity range shown here

Table B-2. Speed of Sound in Water at Selected Temperatures

Temp [°C] Speed of sound [m/s] Temp [°F] Speed of sound [ft/s]

0 1,403 32 4,603

5 1,427 40 4,672

10 1,447 50 4,748

20 1,481 60 4,814

30 1,507 70 4,871

40 1,526 80 4,919

50 1,541 90 4,960

60 1,552 100 4,995

70 1,555 120 5,049

80 1,555 140 5,091

90 1,550 160 5,101

100 1,543 180 5,095

200 5,089

212 5,062

b. Accounting for Effect of Non-Rigid Pipe and Solids on Sound Speed:

For hand calculations of simple piping systems or evaluation of screening criteria, speed of sound in a

piping system may consider the effects of a non-rigid tube or pipe in the manner described by Moody1.

𝐶𝑓𝑝 = 𝐶√1

1+𝐷𝑌𝐿 𝛿𝑌𝑝⁄ Eq. B-1

where: 𝑌𝐿 = 𝜌𝐶2

𝐶𝑓𝑝 = Modified fluid-and-tube speed of sound

C = Speed of sound based on fluid alone

D = Inside diameter of tube or pipe,

δ = Tube or pipe wall thickness

Yp = Modulus of tube or pipe (see below),

YL = Modulus of the fluid

Modulus of tube or pipe 𝑌𝑝 shall be based on the material used in the route (typically steel pipe or

composite hose/pipe systems).

1Moody, F.J. “Introduction to Unsteady Thermofluid Mechanics” John Wiley & Sons, 1990.

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ATTACHMENT B – SPEED OF SOUND DATA (cont.)

For slurry, the effect of solids on sound speed can be accounted for by following Section 7.0 of

RPP-RPT-50042, as follows:

𝐶𝑓𝑝_𝑠 = √1/𝜌𝑚

(1−𝛼𝑠

𝐾𝐿)+

𝛼𝑠𝐾𝑠

+ 𝐷 (𝑌𝑝𝛿)⁄ Eq. B-2

where:

𝐶𝑓𝑝_𝑠 = Modified fluid-and-pipe speed of sound, including effect of solids

ρm = slurry density

αs = solids volume fraction of slurry

KL = liquid bulk density

Ks = solids bulk density

D = hydraulic diameter of pipe

Yp = Modulus of pipe

δ = pipe thickness

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ATTACHMENT C - EXAMPLE SCREENING CRITERION FOR COLUMN SEPARATION

Figure C-1 supports using water as a bounding parameter for vapor pressure.

Figure C-1. Vapor Pressure of Various Fluids.

The screening criteria for fluid column height used in determining the potential for column separation

may be computed according to the following formula:

Hcrit = Patm – Pvapor / g ρ Eqn. C-1

where:

Hcrit = critical height for an unsupported column

Patm = atmospheric pressure

Pvapor = vapor pressure of fluid

ρ = density of fluid

g = acceleration due to gravity

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ATTACHMENT C – EXAMPLE SCREENING CRITERION FOR COLUMN SEPARATION

(cont.)

As an example of the screening criteria for fluid column height used in determining the potential for

column separation, consider:

Water at 140F, the vapor pressure of water is 2.89 psi.

At an elevation of 1000 feet above sea level atmospheric pressure is 14.07 psia.

The density of water at 140F is less than 62 lb/ft3 but this value is used with the maximum specific

gravity of 1.48.

The tallest column of fluid that can be supported by a vacuum equal to the vapor pressure of water under

these conditions may be computed as follows:

The recommended bounding screening criterion is set at 17.5 feet. Refinement of this value may be

determined for any specific application based on specific design conditions.

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ATTACHMENT D - CREDIBLE OVER-PRESSURE CONDITIONS

D.1 OVERPRESSURE PROTECTION PHILOSOPHY

D.2 Double Jeopardy

(API 521 Section 4.2.1) “The causes of overpressure are considered to be unrelated if no process

or mechanical or electrical linkages exist among them, or if the length of time that elapses

between possible successive occurrences of these causes is sufficient to make their classification

unrelated. The simultaneous occurrence of two or more unrelated causes of overpressure (also

known as double or multiple jeopardy) is not a basis for design. Examples of double-jeopardy

scenarios are fire exposure simultaneous with exchanger internal tube failure, fire exposure

simultaneous with failure of administrative controls to drain and depressure isolated equipment,

or operator error that leads to a blocked outlet coincident with a power failure. On the other hand,

instrument air failure during fire exposure may be considered single jeopardy if the fire exposure

causes local air line failures.

This International Standard describes single-jeopardy scenarios that should be considered as a

basis for design. The user may choose to go beyond these practices and assess multiple jeopardy

scenarios. Since such assessments are outside the basis for design, the user is not required to

meet accumulations allowed by the pressure-design code for these scenarios. Acceptance criteria

are the sole responsibility of the user.”

D.1.2 Latent Failures

(API 521 Section 4.2.2) “Latent failures should normally be considered as an existing condition

and not as a cause of overpressure when assessing whether a scenario is single or double

jeopardy. For example, latent failures can exist in instrumentation that prevents it from

functioning favorably during an overpressure condition. It is not double jeopardy to assume the

absence of beneficial instrumentation response in combination with an unrelated overpressure

cause. Likewise, it is not double jeopardy to assume a latent failure of a check valve allowing

reverse flow during a pump failure.”

D.1.3 Operator Error

(API 521 Section 4.2.3) “Operator error is considered a potential source of overpressure.”

Operator error is considered if an operation is required to be performed (e.g., a valve is required

to be manipulated but a different valve is manipulated) and not when operations are not required

(e.g., operator manipulates a valve when it is not required by procedure).

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ATTACHMENT D – CREDIBLE OVER-PRESSURE CONDITIONS (cont.)

D.1.4 Role of Instrumentation in Overpressure Protection

(API 521 Section 4.2.4) “Fail-safe devices, automatic start-up equipment and other conventional

instrumentation should not be a substitute for properly sized pressure-relieving devices as

protection against single-jeopardy overpressure scenarios. There can be circumstances, however,

where the use of pressure-relief devices is impractical and reliance on instrumented safeguards is

needed. Where this is the case, if permitted by local regulations, a pressure-relieving device

might not be required.” (See ASME Code Case 2211 and ASME B&PVC, Section VIII,

Division 1, UG-140 Overpressure Protection by System Design)

D.2 POTENTIALS FOR OVERPRESSURE

Pressure vessels, heat exchangers, operating equipment and piping are designed to contain the

system pressure. The design is based on

a) the normal operating pressure at operating temperatures;

b) the effect of any combination of process upsets that are likely to occur;

c) the differential between the operating, and set pressures of the pressure-relieving device;

d) the effect of any combination of supplemental loadings such as earthquake and wind.

The process-systems designer shall define the minimum pressure-relief capacity required to

prevent the pressure in any piece of equipment from exceeding the maximum allowable

accumulated pressure. The principal causes of overpressure listed in D.2.1 through D.2.19 are

guides to generally accepted practices.

D.2.1 Regulator and Control Valve Failure

The failure of a single pressure regulator or a single control valve must be assumed, using the Cv

for a fully open regulator, and the maximum supply pressure.

D.2.2 Centrifugal Pumps

The accidental pumping against a closed or clogged line, i.e. the centrifugal pump deadhead must

be considered and the PRD must be sized for the maximum pump discharge flow.

D.2.3 Closed outlets on vessels

See API 521 Section 4.3.2.

D.2.4 Inadvertent Valve Opening

The inadvertent opening of any valve from a source of higher pressure.


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D.2.5 Check-Valve Leakage or Failure

One scenario which can occur is when a check valve fails to close when the flow first reverses,

but frees itself because of the reverse flow, then slams shut, causing water hammer severe enough

to cause loss of containment. This type of incident has occurred many times in such diverse

operations as power generation, municipal water distribution, and chemical plant fire-water

distribution and water distribution.


D.2.6 Utility Failure


D.2.7 Electrical or Mechanical Failure


D.2.8 Loss of Fans


D.2.9 Loss of Heat


D.2.10 Loss of Instrument Air or Electric Instrument Power


D.2.11 Reflux Failure


D.2.12 Abnormal Heat Input from Reboilers


D.2.13 Heat Exchanger Tube Failure


D.2.14 Transient Pressure Surges

(API 521 Section 4.3.13)

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D.2.15 Water Hammer

The probability of hydraulic shock waves, known as water hammer, occurring in any liquid-filled

system should be carefully evaluated. Water hammer is a type of overpressure that cannot be

controlled by typical pressure-relief valves, since the response time of the valves can be too slow.

The oscillating peak pressures, measured in milliseconds, can raise the normal operating pressure

by many times. These pressure waves damage the pressure vessels and piping where proper

safeguards have not been incorporated. Water hammer is frequently avoided by limiting the

speed at which valves can be closed in long pipelines. Where water hammer can occur, the use of

pulsation dampeners or special bladder-type surge valves should be considered, contingent on

proper analysis.

D.2.16 Steam Hammer

An oscillating peak-pressure surge, called steam hammer, can occur in piping that contains

compressible fluids. The most common occurrence is generally initiated by rapid valve closure.

This oscillating pressure surge occurs in milliseconds, with a possible pressure rise in the normal

operating pressure by many times, resulting in vibration and violent movement of piping and

possible rupture of equipment. Pressure-relief valves cannot effectively be used as a protective

device because of their slow response time. Avoiding the use of quick-closing valves can prevent

steam hammer.

D.2.17 Condensate-Induced Hammer

Isolation of a steam bubble by cold condensate can lead to the eventual rapid collapse of the

bubble and catastrophic damage to steam pipework. Proper design and operation of the process

system are essential in attempts to eliminate this possibility (e.g. by the use of drains, steam traps,

appropriate pipe slope, training and careful management of change).

The hazard is particularly acute during turnaround and maintenance activities where dead-legs

that trap a steam bubble can be inadvertently created. Pressure-relief devices cannot effectively

be used as a protective device.

D.2.18 Plant Fires


D.2.19 Process Changes/Chemical Reactions


D.2.20 Closed Outlets

See API 521 Section 5.5

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D.2.21 Failure of Process Stream Automatic Controls


D.2.22 Hydraulic Expansion


API 521 Section 5.14.4 Piping provides a method for evaluating if piping with blocked-in liquid

may not require a pressure relief device due to thermal expansion. An equation for calculating a

pressure rise due to simultaneous heating of the pipe and blocked-in liquid is provided.

usq #gcx-2 preparation of piping engineering analyses …

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