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{{#Wiki_filter:TSTF-576 Example Scenarios Slide 2 TSTF-576, Rev. 1 - Methodology Page 10:                                                                                                Page 11:
{{#Wiki_filter:TSTF-576 Example Scenarios
1  Under the proposed SR, the results of the Inservice Testing Program individual valve testing will be 3 The previous cycle RLA reevaluation may result in one of the following outcomes:
reviewed to verify that the collective performance of the S/RVs will ensure Safety Limit 2.1.2 is protected. If all of the required S/RVs actuate within the assumed tolerance, the SR is met.            i. If the previous cycle RLA reevaluation demonstrates that the calculated overpressure is less 3.i      than or equal to the RLA calculated peak overpressure for the limiting event (i.e., the RLA If the as-found individual S/RV performance is not within the inputs and assumptions of the                    results were bounding), then the SR was met and the OPS was operable during the previous previous cycle RLA, the previous cycle overpressure RLA is reevaluated using revised inputs based              cycle. It can be assumed that the current cycle RLA inputs and assumptions contain adequate 2  on the as-found test results and the NRC-approved methodology for the licensee. The purpose of the evaluation is to determine if the RLA of the previous cycle bounded the actual plant conservatism to account for the as-found S/RV performance. No further action is required.
performance and the SR was met. This reevaluation may be performed by the licensee or a vendor.      3.iiii. If the previous cycle RLA reevaluation does not demonstrates that the calculated overpressure The evaluation is performed using the measured S/RV lift settings for tested S/RVs and the upper              is less than or equal to the RLA calculated peak overpressure for the limiting event (i.e., the limits of the ASME Code testing allowance for any S/RVs that were not tested. Any S/RV that was                RLA results are not bounding), the previous cycle overpressure analysis was not consistent required to be tested but that could not be tested, or if the results cannot be determined, is                with actual plant performance and the issue will be entered into the Corrective Action assumed to be out-of-service.                                                                                  Program (as required by 10 CFR 50, Appendix B, Criterion XVII, "Corrective Actions,"). The previous cycle performance will be evaluated for reportability under 10 CFR 50.72 and 10 CFR 50.73.
If the previous cycle RLA reevaluation determines the RLA overpressure analysis did not bound 4  actual plant performance, the current cycle overpressure RLA must be reevaluated to determine if the overpressure RLA bounds the actual plant performance.
The current cycle reevaluation will use the licensee's NRC-approved methodology but with inputs revised to consider the results of the as-found S/RV testing. The nature of the changes to the Note: The red paragraph numbers will be                                                            5  inputs will depend on the cause of the as-found failures and the similarities or differences between the previous cycle and the current cycle. An evaluation of the cause of the as-found failures may referenced in the following slides.                                                                    result in changes to the S/RV tolerances or other assumptions in the reevaluation. If it is determined that the OPS is not operable, the TS Actions require a plant shutdown.


Slide 3 Example Plant Configuration Acronym  Definition
TSTF-576, Rev. 1 - Methodology Page 10:
* Dome Pressure Safety Limit (SL): <1325psig                                           Cycle N  Currently operating plant cycle of operation
Page 11:
* 11 S/RVs, all with same nominal lift setpoints                                       Cycle N-1 Previously operated plant cycle of operation OP        Reactor Vessel Over-Pressure
3 3.i 3.ii 4
* Standard set of assumed S/RV lift setpoints used RLA      Reload Licensing Analysis as input to each cycles RLA:                                                                 (effectively the Overpressure Analysis of Record, re-performed every reload)
5 Note: The red paragraph numbers will be referenced in the following slides.
* 10 valves open at +4 psi higher than nominal setpoint SL        Safety Limit
Slide 2 Under the proposed SR, the results of the Inservice Testing Program individual valve testing will be reviewed to verify that the collective performance of the S/RVs will ensure Safety Limit 2.1.2 is protected. If all of the required S/RVs actuate within the assumed tolerance, the SR is met.
If the as-found individual S/RV performance is not within the inputs and assumptions of the previous cycle RLA, the previous cycle overpressure RLA is reevaluated using revised inputs based on the as-found test results and the NRC-approved methodology for the licensee. The purpose of the evaluation is to determine if the RLA of the previous cycle bounded the actual plant performance and the SR was met. This reevaluation may be performed by the licensee or a vendor.
The evaluation is performed using the measured S/RV lift settings for tested S/RVs and the upper limits of the ASME Code testing allowance for any S/RVs that were not tested. Any S/RV that was required to be tested but that could not be tested, or if the results cannot be determined, is assumed to be out-of-service.
The previous cycle RLA reevaluation may result in one of the following outcomes:
i.
If the previous cycle RLA reevaluation demonstrates that the calculated overpressure is less than or equal to the RLA calculated peak overpressure for the limiting event (i.e., the RLA results were bounding), then the SR was met and the OPS was operable during the previous cycle. It can be assumed that the current cycle RLA inputs and assumptions contain adequate conservatism to account for the as-found S/RV performance. No further action is required.
ii.
If the previous cycle RLA reevaluation does not demonstrates that the calculated overpressure is less than or equal to the RLA calculated peak overpressure for the limiting event (i.e., the RLA results are not bounding), the previous cycle overpressure analysis was not consistent with actual plant performance and the issue will be entered into the Corrective Action Program (as required by 10 CFR 50, Appendix B, Criterion XVII, "Corrective Actions,"). The previous cycle performance will be evaluated for reportability under 10 CFR 50.72 and 10 CFR 50.73.
If the previous cycle RLA reevaluation determines the RLA overpressure analysis did not bound actual plant performance, the current cycle overpressure RLA must be reevaluated to determine if the overpressure RLA bounds the actual plant performance.
The current cycle reevaluation will use the licensee's NRC-approved methodology but with inputs revised to consider the results of the as-found S/RV testing. The nature of the changes to the inputs will depend on the cause of the as-found failures and the similarities or differences between the previous cycle and the current cycle. An evaluation of the cause of the as-found failures may result in changes to the S/RV tolerances or other assumptions in the reevaluation. If it is determined that the OPS is not operable, the TS Actions require a plant shutdown.
1 2
 
Example Plant Configuration
* Dome Pressure Safety Limit (SL): <1325psig
* 11 S/RVs, all with same nominal lift setpoints
* Standard set of assumed S/RV lift setpoints used as input to each cycles RLA:
* 10 valves open at +4 psi higher than nominal setpoint
* 1 valve fails to open (1 SRVOOS)
* 1 valve fails to open (1 SRVOOS)
S/RV      Safety / Relief Valve Legend for scenario slides:                                                             SR        Surveillance Requirement
Legend for scenario slides:
-  Blue boxes describe the analyses/evaluations that exist prior to performing SR SRVOOS    S/RV Out of Service (i.e., the S/RV is assumed to not open)
Slide 3 Blue boxes describe the analyses/evaluations that exist prior to performing SR Orange boxes describe the available testing to support the SR Yellow boxes describe necessary explicit re-analyses, likely performed by the vendor Green boxes describe evaluations that can be performed by utility w/o need for explicit vendor re-analysis.
-  Orange boxes describe the available testing to support the SR
Acronym Definition Cycle N Currently operating plant cycle of operation Cycle N-1 Previously operated plant cycle of operation OP Reactor Vessel Over-Pressure RLA Reload Licensing Analysis (effectively the Overpressure Analysis of Record, re-performed every reload)
-  Yellow boxes describe necessary explicit re-analyses, likely performed by the vendor
SL Safety Limit S/RV Safety / Relief Valve SR Surveillance Requirement SRVOOS S/RV Out of Service (i.e., the S/RV is assumed to not open)
-  Green boxes describe evaluations that can be performed by utility w/o need for explicit vendor re-analysis.


Slide 4 SR Completion Steps:
Scenario 1 (SR Met, RLA Valid)
Cycle N-1 S/RV As-Found Test Results 10 S/RV test at +2 1 S/RV tests at +6 (accounted for by RLA 1SRVOOS)
Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)
SR Completion Steps:
Paragraph 1 - Satisfied (for N & N-1)
Paragraph 1 - Satisfied (for N & N-1)
Scenario 1 (SR Met, RLA Valid)                                                        (Cycle N-1 test results are all less limiting than the standard set of Cycle N-1                                            Cycle N                  assumed S/RV lift setpoints which (operation complete)                                (currently operating)            support the Cycle N-1 and Cycle N RLA:                                              RLA:                                          RLAs, thus both RLAs remains
(Cycle N-1 test results are all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 and Cycle N RLAs, thus both RLAs remains bounding)
- Assumes: 10 S/RVs set at +4 psi                - Assumes: 10 S/RVs set at +4 psi            bounding) and 1 SRVOOS                                      and 1 SRVOOS
SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed (The standard set of assumed S/RV lift setpoints which support the Cycle N RLA have been validated as conservative based directly on the Cycle N-1 test results)
- Yields: 1270 psig < 1325 psig SL                - Yields: 1290 psig < 1325 psig SL                      SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N-1 S/RV As-Found Test Results                  Cycle N Current S/RV Setpoints 10 S/RV test at +2                                  (not measurable during cycle operation; 1 S/RV tests at +6 (accounted for by RLA 1SRVOOS)  all as-left setpoints were within tolerance)
Cycle N SR Evaluation The assumed S/RV lift setpoints input to the RLA are already more conservative than test results Thus, the existing Cycle N-1 RLA SL confirmation analysis is bounding Satisfies SR for Cycle N-1 Cycle N-1 (operation complete)
Cycle N SR Evaluation                     Cycle N SR Between Performance
RLA:
- The assumed S/RV lift setpoints                                   Evaluation input to the RLA are already more                   Explicit Evaluation Not Needed conservative than test results                   (The standard set of assumed S/RV lift
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)
- Thus, the existing Cycle N-1 RLA                  setpoints which support the Cycle N RLA SL confirmation analysis is bounding           have been validated as conservative based directly on the Cycle N-1 test results)
RLA:
Satisfies SR for Cycle N-1
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 4


Slide 5 SR Completion Steps:
Scenario 2 (SR Met, RLA Valid)
Paragraph 1 - Not Satisfied Scenario 2 (SR Met, RLA Valid)                                          (Cycle N-1 test results are NOT all less limiting than the standard set of Cycle N-1                                Cycle N                  assumed S/RV lift setpoints which (operation complete)                    (currently operating)            support the Cycle N-1 RLA, thus the RLA:                                  RLA:                                          Cycle N-1 RLA is not known to be
Cycle N-1 S/RV As-Found Test Results 9 S/RVs test at +2 2 S/RVs test at +6 SR Completion Steps:
- Assumes: 10 S/RVs set at +4 psi    - Assumes: 10 S/RVs set at +4 psi            bounding/conservative) and 1 SRVOOS                          and 1 SRVOOS                              Paragraph 2 - Performed
Paragraph 1 - Not Satisfied (Cycle N-1 test results are NOT all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 RLA, thus the Cycle N-1 RLA is not known to be bounding/conservative)
- Yields: 1270 psig < 1325 psig SL    - Yields: 1290 psig < 1325 psig SL            (explicit re-analysis of Cycle N-1)
Paragraph 2 - Performed (explicit re-analysis of Cycle N-1)
Paragraph 3.i - Satisfied (for Cycle N &
Paragraph 3.i - Satisfied (for Cycle N &
Cycle N-1 S/RV As-Found Test Results      Cycle N Current S/RV Setpoints          N-1) 9 S/RVs test at +2                      (not measurable during cycle operation;    (re-analysis demonstrates that Cycle 2 S/RVs test at +6                    all as-left setpoints were within tolerance) N-1 RLA inputs yield conservative OP results. Thus, the standard set of Cycle N-1 SR Evaluation        Cycle N SR Between Performance            assumed S/RV lift setpoints are Explicit re-analysis performed                          Evaluation                  confirmed conservative, and both Cycle
N-1)
- Assumes: Cycle N-1 As-Found               Explicit Evaluation Not Needed         N-1 and N RLAs are validated)
(re-analysis demonstrates that Cycle N-1 RLA inputs yield conservative OP results. Thus, the standard set of assumed S/RV lift setpoints are confirmed conservative, and both Cycle N-1 and N RLAs are validated)
- Yields: 1250 psig                      (The standard set of assumed S/RV lift
SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N-1 SR Evaluation Explicit re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1250 psig
          < 1270 psig RLA              setpoints which support the Cycle N RLA               SR MET for Cycle N-1,
< 1270 psig RLA
          < Safety Limit  SR MET          have effectively been validated to                 Cycle N RLA is Valid yield conservative OP results by the Cycle N-1 re-analysis)
< Safety Limit SR MET Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed (The standard set of assumed S/RV lift setpoints which support the Cycle N RLA have effectively been validated to yield conservative OP results by the Cycle N-1 re-analysis)
Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)
Cycle N-1 (operation complete)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 5


Slide 6 SR Completion Steps:
Scenario 3 (SR Met, RLA Valid)
Paragraph 1 - Not Satisfied Scenario 3 (SR Met, RLA Valid)                                              Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
Cycle N-1 S/RV As-Found Test Results 5 S/RVs test at +2 6 S/RVs test at +6 SR Completion Steps:
Cycle N-1                                    Cycle N                  (re-analysis did not demonstrates that (operation complete)                    (currently operating)              the standard set of assumed S/RV lift RLA:                                  RLA:                                            setpoints yield bounding RLA results)
Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
- Assumes: 10 S/RVs set at +4 psi    - Assumes: 10 S/RVs set at +4 psi                Paragraph 3.ii - Satisfied (for N-1) and 1 SRVOOS                            and 1 SRVOOS                                (Cycle N-1 re-analysis shows OP with
(re-analysis did not demonstrates that the standard set of assumed S/RV lift setpoints yield bounding RLA results)
- Yields: 1270 psig < 1325 psig SL    - Yields: 1290 psig < 1325 psig SL              as-found setpoints is < SL)
Paragraph 3.ii - Satisfied (for N-1)
Paragraph 4 - Performed Cycle N-1 S/RV As-Found Test Results      Cycle N Current S/RV Setpoints            (re-evaluation of Cycle N overpressure 5 S/RVs test at +2                      (not measurable during cycle operation;      RLA performed) 6 S/RVs test at +6                      all as-left setpoints were within tolerance)  Paragraph 5 - Satisfied (for N)
(Cycle N-1 re-analysis shows OP with as-found setpoints is < SL)
(explicit Cycle N RLA re-analysis is not necessary because consideration of the Cycle N-1 as-found Cycle N-1 SR Evaluation        Cycle N SR Between Performance              2-stage S/RV test results does not directly indicate Explicit Re-analysis performed                            Evaluation                  a concern with the 3-stage S/RVs installed in Cycle
Paragraph 4 - Performed (re-evaluation of Cycle N overpressure RLA performed)
- Assumes: Cycle N-1 As-Found         Qualitative Evaluation:                         N. After qualitative evaluation, the utility
Paragraph 5 - Satisfied (for N)
                                      -    2 stage were installed in Cycle N-1,       demonstrates that the existing technical basis for
(explicit Cycle N RLA re-analysis is not necessary because consideration of the Cycle N-1 as-found 2-stage S/RV test results does not directly indicate a concern with the 3-stage S/RVs installed in Cycle N. After qualitative evaluation, the utility demonstrates that the existing technical basis for their existing Cycle N RLA S/RV setpoint assumptions has not been invalidated)
- Yields: 1290 psig                                                                    their existing Cycle N RLA S/RV setpoint 3 stage are installed in Cycle N
SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1290 psig
          > 1270 psig RLA            -    Thus Cycle N-1 as-found measurements do not assumptions has not been invalidated)
> 1270 psig RLA
          < Safety Limit  SR MET        invalidate Cycle N RLA input assumptions               SR MET for Cycle N-1, Existing RLA continues to satisfies SR for                 Cycle N RLA is Valid Cycle N
< Safety Limit SR MET Cycle N SR Between Performance Evaluation Qualitative Evaluation:
2 stage were installed in Cycle N-1, 3 stage are installed in Cycle N Thus Cycle N-1 as-found measurements do not invalidate Cycle N RLA input assumptions Existing RLA continues to satisfies SR for Cycle N Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)
Cycle N-1 (operation complete)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 6


Slide 7 SR Completion Steps:
Scenario 4 (SR Met, RLA Valid)
Paragraph 1 - Not Satisfied Scenario 4 (SR Met, RLA Valid)                                                                                                              Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
Cycle N-1 S/RV As-Found Test Results 5 S/RVs test at +2 6 S/RVs test at +6 SR Completion Steps:
Cycle N-1                                                                      Cycle N                                          Paragraph 3.ii - Satisfied (for (operation complete)                                                          (currently operating)                                          N-1)
Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
RLA:                                                                          RLA:                                                                            Paragraph 4 - Performed
Paragraph 3.ii - Satisfied (for N-1)
- Assumes: 10 S/RVs set at +4 psi                                            - Assumes: 10 S/RVs set at +4 psi                                              Paragraph 5 - Satisfied (for N)
Paragraph 4 - Performed Paragraph 5 - Satisfied (for N)
                                                                                                                                                              - Update the standard set of assumed S/RV lift and 1 SRVOOS                                                                and 1 SRVOOS                                                              setpoints to consider the results of as-found Cycle
- Update the standard set of assumed S/RV lift setpoints to consider the results of as-found Cycle N-1 S/RV testing
- Yields: 1270 psig < 1325 psig SL                                            - Yields: 1290 psig < 1325 psig SL                                              N-1 S/RV testing
- Use the updated set of standard S/RV setpoints as input to an updated Cycle N RLA
                                                                                                                                                              - Use the updated set of standard S/RV setpoints as input to an updated Cycle N RLA Cycle N-1 S/RV As-Found Test Results                                              Cycle N Current S/RV Setpoints                                          - The updated Cycle N RLA confirms the SL is met 5 S/RVs test at +2                                                              (not measurable during cycle operation;                                      for Cycle N 6 S/RVs test at +6                                                              all as-left setpoints were within tolerance)                                                SR MET for Cycle N-1, Valid Updated Cycle N RLA Obtained Cycle N-1 SR Evaluation                                           Cycle N SR Between Performance Explicit Re-analysis performed                                                                         Evaluation                                            Update Standard Set of Assumed S/RV
- The updated Cycle N RLA confirms the SL is met for Cycle N SR MET for Cycle N-1, Valid Updated Cycle N RLA Obtained Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1290 psig  
- Assumes: Cycle N-1 As-Found                                                 Requires RLA Update                                                                      Lift Setpoints used in RLAs *
> 1270 psig RLA
- Yields: 1290 psig                                                           ----------------------------------------------------                            Explicit Cycle N-1 Re-analysis of:
< Safety Limit SR MET Cycle N SR Between Performance Evaluation Requires RLA Update Explicit RLA Update Re-analysis Assumes: 10 S/RVs set at +5 psi and 1 SRVOOS (updated assumed S/RV setpoints)
                  > 1270 psig RLA                                             Explicit RLA Update Re-analysis                                                       10 S/RVs set at +5 psi and 1 SRVOOS
Yields: 1310 psig, <1325 psig SL Update Standard Set of Assumed S/RV Lift Setpoints used in RLAs
                                                                              -   Assumes: 10 S/RVs set at +5 psi and 1 SRVOOS                                       (considers Cycle N-1 as-found setpoints)
* Explicit Cycle N-1 Re-analysis of:
                  < Safety Limit  SR MET                                              (updated assumed S/RV setpoints)                                        -    Yields: 1310 psig
10 S/RVs set at +5 psi and 1 SRVOOS (considers Cycle N-1 as-found setpoints)
                                                                              -    Yields: 1310 psig, <1325 psig SL                                           -   Thus: Conservative for Generic Use
Yields: 1310 psig Thus: Conservative for Generic Use Cycle N-1 (operation complete)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)
* This describes a possible technique for updating the standard set of S/RV setpoints to consider the Cycle N-1 test results. Specific approaches to satisfying Paragraph 5 may vary between utilities.
* This describes a possible technique for updating the standard set of S/RV setpoints to consider the Cycle N-1 test results. Specific approaches to satisfying Paragraph 5 may vary between utilities.
Slide 7


Slide 8 SR Completion Steps:
Scenario 5 (SR Met, RLA Not Valid)
Paragraph 1 - Not Satisfied Scenario 5 (SR Met, RLA Not Valid)                                              Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
Cycle N-1 S/RV As-Found Test Results 2 S/RVs test at +2 9 S/RVs test at +6 SR Completion Steps:
Cycle N-1                                    Cycle N                      Paragraph 3.ii - Satisfied (for N-1)
Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
(operation complete)                      (currently operating)                  Paragraph 4 - Performed RLA:                                  RLA:                                                Paragraph 5 - SR Not Met (for N)
Paragraph 3.ii - Satisfied (for N-1)
                                                                                          - Update the standard set of assumed S/RV lift
Paragraph 4 - Performed Paragraph 5 - SR Not Met (for N)
- Assumes: 10 S/RVs set at +4 psi    - Assumes: 10 S/RVs set at +4 psi                    setpoints to consider the results of as-found Cycle and 1 SRVOOS                            and 1 SRVOOS                                    N-1 S/RV testing
- Update the standard set of assumed S/RV lift setpoints to consider the results of as-found Cycle N-1 S/RV testing
- Yields: 1270 psig < 1325 psig SL    - Yields: 1290 psig < 1325 psig SL                  - Use the updated set of standard S/RV setpoints as input to an updated Cycle N RLA
- Use the updated set of standard S/RV setpoints as input to an updated Cycle N RLA
                                                                                          - The updated Cycle N RLA can not confirm that Cycle N-1 S/RV As-Found Test Results      Cycle N Current S/RV Setpoints                the SR will be met at end of Cycle N 2 S/RVs test at +2                      (not measurable during cycle operation;                      SR MET for Cycle N-1, 9 S/RVs test at +6                      all as-left setpoints were within tolerance)          Valid Cycle N RLA NOT Obtained Cycle N-1 SR Evaluation         Cycle N SR Between Performance Explicit Re-analysis performed                             Evaluation                      Update Standard Set of Assumed S/RV
- The updated Cycle N RLA can not confirm that the SR will be met at end of Cycle N SR MET for Cycle N-1, Valid Cycle N RLA NOT Obtained Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1318 psig
- Assumes: Cycle N-1 As-Found         Requires RLA Update                                            Lift Setpoints used in RLAs
> 1270 psig RLA
- Yields: 1318 psig                   ----------------------------------------------------  Explicit Cycle N-1 Re-analysis of:
< Safety Limit SR MET Cycle N SR Between Performance Evaluation Requires RLA Update Explicit RLA Update Re-analysis Assumes: 11 S/RVs set at +6 psi (updated standard set of S/RV setpoints)
          > 1270 psig RLA           Explicit RLA Update Re-analysis                                     11 S/RVs set at +6 psi
Yields: 1340 psig, >1325 psig SL Update Standard Set of Assumed S/RV Lift Setpoints used in RLAs Explicit Cycle N-1 Re-analysis of:
                                      -   Assumes: 11 S/RVs set at +6 psi                         (considers Cycle N-1 as-found results)
11 S/RVs set at +6 psi (considers Cycle N-1 as-found results)
          < Safety Limit  SR MET          (updated standard set of S/RV setpoints)       -   Yields: 1320 psig, >1318 psig
Yields: 1320 psig, >1318 psig Thus: Conservative for Generic Use Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)
                                      -    Yields: 1340 psig, >1325 psig SL                 -  Thus: Conservative for Generic Use
Cycle N-1 (operation complete)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 8


Slide 9 SR Completion Steps:
Scenario 6 (SR NOT Met, RLA Valid)
Paragraph 1 - Not Satisfied Scenario 6 (SR NOT Met, RLA Valid)                                                                                              Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
Cycle N-1 S/RV As-Found Test Results 2 S/RVs test at +2 9 S/RVs test at +6 SR Completion Steps:
Cycle N-1                                                                  Cycle N                                    Paragraph 3.ii - SR Not Met (for N-1)
Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)
(Cycle N-1 re-analysis shows that Cycle N-1 (operation complete)                                                      (currently operating)                                overpressure analysis performed with S/RV RLA:                                                                        RLA:                                                                setpoints at as-found values is > SL)
Paragraph 3.ii - SR Not Met (for N-1)
- Assumes: 10 S/RVs set at +4 psi                                          - Assumes: 10 S/RVs set at +4 psi                                    Paragraph 4 - Performed and 1 SRVOOS                                                                and 1 SRVOOS                                                    Paragraph 5 - Satisfied (for N)
(Cycle N-1 re-analysis shows that Cycle N-1 overpressure analysis performed with S/RV setpoints at as-found values is > SL)
- Yields: 1280 psig < 1325 psig SL                                          - Yields: 1270 psig < 1325 psig SL                                  (standard setpoint input assumptions revised to consider Cycle N-1 testing, used to produce updated Cycle N RLA, and confirms the SL is Cycle N-1 S/RV As-Found Test Results                                            Cycle N Current S/RV Setpoints                                satisfied for Cycle N due to a less severe Cycle N 2 S/RVs test at +2                                                            (not measurable during cycle operation;                          core design) 9 S/RVs test at +6                                                            all as-left setpoints were within tolerance)
Paragraph 4 - Performed Paragraph 5 - Satisfied (for N)
SR NOT Met* for Cycle N-1, Valid Updated Cycle N RLA Obtained Cycle N-1 SR Evaluation                                           Cycle N SR Between Performance Explicit Re-analysis performed                                                                     Evaluation                                    Update Standard Set of Assumed S/RV
(standard setpoint input assumptions revised to consider Cycle N-1 testing, used to produce updated Cycle N RLA, and confirms the SL is satisfied for Cycle N due to a less severe Cycle N core design)
- Assumes: Cycle N-1 As-Found                                               Requires RLA Update                                                              Lift Setpoints used in RLAs
SR NOT Met* for Cycle N-1, Valid Updated Cycle N RLA Obtained Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1328 psig
- Yields: 1328 psig                                                         ----------------------------------------------------                  Explicit Cycle N-1 Re-analysis of:
> 1280 psig RLA
                > 1280 psig RLA                                           Explicit RLA Update Re-analysis                                                         11 S/RVs set at +6 psi
> Safety Limit SR NOT MET Cycle N SR Between Performance Evaluation Requires RLA Update Explicit RLA Update Re-analysis Assumes: 11 S/RVs set at +6 psi (updated standard set of S/RV setpoints)
                                                                            -   Assumes: 11 S/RVs set at +6 psi                                           (considers Cycle N-1 as-found results)
Yields: 1320 psig, <1325 psig SL Update Standard Set of Assumed S/RV Lift Setpoints used in RLAs Explicit Cycle N-1 Re-analysis of:
                > Safety Limit  SR NOT MET                                      (updated standard set of S/RV setpoints)                      -    Yields: 1330 psig, >1328 psig
11 S/RVs set at +6 psi (considers Cycle N-1 as-found results)
                                                                            -    Yields: 1320 psig, <1325 psig SL                                 -   Thus: Conservative for Generic Use
Yields: 1330 psig, >1328 psig Thus: Conservative for Generic Use Cycle N-1 (operation complete)
* More detailed operability assessments for Cycle N-1 may be able to show SR was met. The approach shown here assumes only NRC approved methodologies for cycle OP RLA analyses are utilized.
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1280 psig < 1325 psig SL Cycle N (currently operating)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Slide 9 Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)
* More detailed operability assessments for Cycle N-1 may be able to show SR was met. The approach shown here assumes only NRC approved methodologies for cycle OP RLA analyses are utilized.  


Slide 10 SR Completion Steps:
Scenario 7 (SR Met, RLA Valid)
Cycle N-1 S/RV As-Found Test Results 8 S/RV test at +2 2 S/RVs test at -6 (below +/-3 ASME tolerance)
SR Completion Steps:
Paragraph 1 - Satisfied (for N & N-1)
Paragraph 1 - Satisfied (for N & N-1)
Scenario 7 (SR Met, RLA Valid)                                                      (Cycle N-1 test results are all less limiting than the standard set of Cycle N-1                                          Cycle N                    assumed S/RV lift setpoints which (operation complete)                            (currently operating)                support the Cycle N-1 and Cycle N RLA:                                          RLA:                                              RLAs for the purposes of the
(Cycle N-1 test results are all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 and Cycle N RLAs for the purposes of the overpressure analysis,* thus both RLAs remains bounding )
- Assumes: 10 S/RVs set at +4 psi              - Assumes: 10 S/RVs set at +4 psi                overpressure analysis,* thus both and 1 SRVOOS                                  and 1 SRVOOS                                  RLAs remains bounding )
SR MET for Cycle N-1, Cycle N RLA is Valid
- Yields: 1270 psig < 1325 psig SL            - Yields: 1290 psig < 1325 psig SL SR MET for Cycle N-1, Cycle N-1 S/RV As-Found Test Results              Cycle N Current S/RV Setpoints                          Cycle N RLA is Valid 8 S/RV test at +2                                (not measurable during cycle operation; 2 S/RVs test at -6 (below +/-3 ASME tolerance)  all as-left setpoints were within tolerance)
* However, due to valves opening below allowable set pressure, overall potential impacts to other analyses due to the valves which opened below the ASME testing tolerance would be evaluated through the utilitys corrective action program Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed (theres no concern with Cycle N standard set of RLA inputs for the purpose of the overpressure analysis, as theyve been validated as conservative for Cycle N-1)
* However, due to valves opening Cycle N SR Evaluation                  Cycle N SR Between Performance                below allowable set pressure, overall
Cycle N SR Evaluation The standard set of RLA input assumptions are already more conservative than test results for the purpose of the overpressure analysis, so RLA results are bounding Satisfies SR for Cycle N-1 Cycle N-1 (operation complete)
-  The standard set of RLA input                                  Evaluation                    potential impacts to other analyses assumptions are already more                    Explicit Evaluation Not Needed              due to the valves which opened below conservative than test results for the     (theres no concern with Cycle N standard set of the ASME testing tolerance would be purpose of the overpressure analysis,      RLA inputs for the purpose of the overpressure   evaluated through the utilitys so RLA results are bounding                      analysis, as theyve been validated as conservative for Cycle N-1) corrective action program
RLA:
- Satisfies SR for Cycle N-1
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)
RLA:
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 10 Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)


Slide 11 SR Completion Steps:
Scenario 8 (SR Met, RLA Valid)
Cycle N-1 S/RV As-Found Test Results (limited-scope valve testing) 5 of 11 total S/RVs tested:
4 S/RV test at +2 (within ASME tolerance) 1 S/RVs test at +6 (above ASME tolerance)
ASME code does not require further explicit testing of valves against +/-3 tolerance remaining 6 S/RVs assumed test result at +3 (top end of ASME tolerance)
SR Completion Steps:
Paragraph 1 - Satisfied (for N & N-1)
Paragraph 1 - Satisfied (for N & N-1)
Scenario 8 (SR Met, RLA Valid)                                                      (The combination of the Cycle N-1 measured test results and assumed Cycle N-1                                Cycle N SR Evaluation              test results allowed per ASME code (operation complete)                                                                are all less limiting than the standard 4 S/RV test at +2 and           set of assumed S/RV lift setpoints RLA:                                                    6 S/RV assumed test result at +3
(The combination of the Cycle N-1 measured test results and assumed test results allowed per ASME code are all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 and Cycle N RLAs, thus both RLAs remains bounding)
- Assumes: 10 S/RVs set at +4 psi                                  are bounded by               which support the Cycle N-1 and Cycle and 1 SRVOOS                                          RLA assumed 10 S/RV at +4 psi         N RLAs, thus both RLAs remains
SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N SR Evaluation 4 S/RV test at +2 and 6 S/RV assumed test result at +3 are bounded by RLA assumed 10 S/RV at +4 psi 1 S/RV test at +6 is bounded by RLA assumed 1 SRVOOS
- Yields: 1270 psig < 1325 psig SL                                                              bounding) 1 S/RV test at +6 is bounded by Cycle N-1 S/RV As-Found Test Results                        RLA assumed 1 SRVOOS                       SR MET for Cycle N-1, (limited-scope valve testing)                                                                    Cycle N RLA is Valid


== Conclusion:==
==
the assumed S/RV lift setpoints 5 of 11 total S/RVs tested:
Conclusion:==
input to the RLA are already more
the assumed S/RV lift setpoints input to the RLA are already more conservative than test results Thus, the existing Cycle N-1 RLA SL confirmation analysis is bounding Satisfies SR for N-1 Cycle N-1 (operation complete)
-  4 S/RV test at +2    (within ASME tolerance) conservative than test results
RLA:
-  1 S/RVs test at +6  (above ASME tolerance)
Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Slide 11 Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed}}
                                                  -  Thus, the existing Cycle N-1 RLA SL confirmation analysis is bounding ASME code does not require further explicit                    Satisfies SR for N-1 testing of valves against +/-3 tolerance Cycle N SR Between Performance
-  remaining 6 S/RVs assumed test result at +3                  Evaluation (top end of ASME tolerance)                        Explicit Evaluation Not Needed}}

Latest revision as of 13:30, 29 November 2024

TSTF-576 Example Scenarios for 12/7/2020 Meeting
ML20329A341
Person / Time
Site: Technical Specifications Task Force
Issue date: 11/24/2020
From:
BWR Owners Group, Technical Specifications Task Force
To:
Office of Nuclear Reactor Regulation
Honcharik M, NRR/DSS, 301-415-1774
References
TSTF-576
Download: ML20329A341 (11)
v • d • e


Text

TSTF-576 Example Scenarios

TSTF-576, Rev. 1 - Methodology Page 10:

Page 11:

3 3.i 3.ii 4

5 Note: The red paragraph numbers will be referenced in the following slides.

Slide 2 Under the proposed SR, the results of the Inservice Testing Program individual valve testing will be reviewed to verify that the collective performance of the S/RVs will ensure Safety Limit 2.1.2 is protected. If all of the required S/RVs actuate within the assumed tolerance, the SR is met.

If the as-found individual S/RV performance is not within the inputs and assumptions of the previous cycle RLA, the previous cycle overpressure RLA is reevaluated using revised inputs based on the as-found test results and the NRC-approved methodology for the licensee. The purpose of the evaluation is to determine if the RLA of the previous cycle bounded the actual plant performance and the SR was met. This reevaluation may be performed by the licensee or a vendor.

The evaluation is performed using the measured S/RV lift settings for tested S/RVs and the upper limits of the ASME Code testing allowance for any S/RVs that were not tested. Any S/RV that was required to be tested but that could not be tested, or if the results cannot be determined, is assumed to be out-of-service.

The previous cycle RLA reevaluation may result in one of the following outcomes:

i.

If the previous cycle RLA reevaluation demonstrates that the calculated overpressure is less than or equal to the RLA calculated peak overpressure for the limiting event (i.e., the RLA results were bounding), then the SR was met and the OPS was operable during the previous cycle. It can be assumed that the current cycle RLA inputs and assumptions contain adequate conservatism to account for the as-found S/RV performance. No further action is required.

ii.

If the previous cycle RLA reevaluation does not demonstrates that the calculated overpressure is less than or equal to the RLA calculated peak overpressure for the limiting event (i.e., the RLA results are not bounding), the previous cycle overpressure analysis was not consistent with actual plant performance and the issue will be entered into the Corrective Action Program (as required by 10 CFR 50, Appendix B, Criterion XVII, "Corrective Actions,"). The previous cycle performance will be evaluated for reportability under 10 CFR 50.72 and 10 CFR 50.73.

If the previous cycle RLA reevaluation determines the RLA overpressure analysis did not bound actual plant performance, the current cycle overpressure RLA must be reevaluated to determine if the overpressure RLA bounds the actual plant performance.

The current cycle reevaluation will use the licensee's NRC-approved methodology but with inputs revised to consider the results of the as-found S/RV testing. The nature of the changes to the inputs will depend on the cause of the as-found failures and the similarities or differences between the previous cycle and the current cycle. An evaluation of the cause of the as-found failures may result in changes to the S/RV tolerances or other assumptions in the reevaluation. If it is determined that the OPS is not operable, the TS Actions require a plant shutdown.

1 2

Example Plant Configuration

  • Dome Pressure Safety Limit (SL): <1325psig
  • 11 S/RVs, all with same nominal lift setpoints
  • Standard set of assumed S/RV lift setpoints used as input to each cycles RLA:
  • 10 valves open at +4 psi higher than nominal setpoint
  • 1 valve fails to open (1 SRVOOS)

Legend for scenario slides:

Slide 3 Blue boxes describe the analyses/evaluations that exist prior to performing SR Orange boxes describe the available testing to support the SR Yellow boxes describe necessary explicit re-analyses, likely performed by the vendor Green boxes describe evaluations that can be performed by utility w/o need for explicit vendor re-analysis.

Acronym Definition Cycle N Currently operating plant cycle of operation Cycle N-1 Previously operated plant cycle of operation OP Reactor Vessel Over-Pressure RLA Reload Licensing Analysis (effectively the Overpressure Analysis of Record, re-performed every reload)

SL Safety Limit S/RV Safety / Relief Valve SR Surveillance Requirement SRVOOS S/RV Out of Service (i.e., the S/RV is assumed to not open)

Scenario 1 (SR Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results 10 S/RV test at +2 1 S/RV tests at +6 (accounted for by RLA 1SRVOOS)

Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

SR Completion Steps:

Paragraph 1 - Satisfied (for N & N-1)

(Cycle N-1 test results are all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 and Cycle N RLAs, thus both RLAs remains bounding)

SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed (The standard set of assumed S/RV lift setpoints which support the Cycle N RLA have been validated as conservative based directly on the Cycle N-1 test results)

Cycle N SR Evaluation The assumed S/RV lift setpoints input to the RLA are already more conservative than test results Thus, the existing Cycle N-1 RLA SL confirmation analysis is bounding Satisfies SR for Cycle N-1 Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 4

Scenario 2 (SR Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results 9 S/RVs test at +2 2 S/RVs test at +6 SR Completion Steps:

Paragraph 1 - Not Satisfied (Cycle N-1 test results are NOT all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 RLA, thus the Cycle N-1 RLA is not known to be bounding/conservative)

Paragraph 2 - Performed (explicit re-analysis of Cycle N-1)

Paragraph 3.i - Satisfied (for Cycle N &

N-1)

(re-analysis demonstrates that Cycle N-1 RLA inputs yield conservative OP results. Thus, the standard set of assumed S/RV lift setpoints are confirmed conservative, and both Cycle N-1 and N RLAs are validated)

SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N-1 SR Evaluation Explicit re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1250 psig

< 1270 psig RLA

< Safety Limit SR MET Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed (The standard set of assumed S/RV lift setpoints which support the Cycle N RLA have effectively been validated to yield conservative OP results by the Cycle N-1 re-analysis)

Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 5

Scenario 3 (SR Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results 5 S/RVs test at +2 6 S/RVs test at +6 SR Completion Steps:

Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)

(re-analysis did not demonstrates that the standard set of assumed S/RV lift setpoints yield bounding RLA results)

Paragraph 3.ii - Satisfied (for N-1)

(Cycle N-1 re-analysis shows OP with as-found setpoints is < SL)

Paragraph 4 - Performed (re-evaluation of Cycle N overpressure RLA performed)

Paragraph 5 - Satisfied (for N)

(explicit Cycle N RLA re-analysis is not necessary because consideration of the Cycle N-1 as-found 2-stage S/RV test results does not directly indicate a concern with the 3-stage S/RVs installed in Cycle N. After qualitative evaluation, the utility demonstrates that the existing technical basis for their existing Cycle N RLA S/RV setpoint assumptions has not been invalidated)

SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1290 psig

> 1270 psig RLA

< Safety Limit SR MET Cycle N SR Between Performance Evaluation Qualitative Evaluation:

2 stage were installed in Cycle N-1, 3 stage are installed in Cycle N Thus Cycle N-1 as-found measurements do not invalidate Cycle N RLA input assumptions Existing RLA continues to satisfies SR for Cycle N Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 6

Scenario 4 (SR Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results 5 S/RVs test at +2 6 S/RVs test at +6 SR Completion Steps:

Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)

Paragraph 3.ii - Satisfied (for N-1)

Paragraph 4 - Performed Paragraph 5 - Satisfied (for N)

- Update the standard set of assumed S/RV lift setpoints to consider the results of as-found Cycle N-1 S/RV testing

- Use the updated set of standard S/RV setpoints as input to an updated Cycle N RLA

- The updated Cycle N RLA confirms the SL is met for Cycle N SR MET for Cycle N-1, Valid Updated Cycle N RLA Obtained Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1290 psig

> 1270 psig RLA

< Safety Limit SR MET Cycle N SR Between Performance Evaluation Requires RLA Update Explicit RLA Update Re-analysis Assumes: 10 S/RVs set at +5 psi and 1 SRVOOS (updated assumed S/RV setpoints)

Yields: 1310 psig, <1325 psig SL Update Standard Set of Assumed S/RV Lift Setpoints used in RLAs

  • Explicit Cycle N-1 Re-analysis of:

10 S/RVs set at +5 psi and 1 SRVOOS (considers Cycle N-1 as-found setpoints)

Yields: 1310 psig Thus: Conservative for Generic Use Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

  • This describes a possible technique for updating the standard set of S/RV setpoints to consider the Cycle N-1 test results. Specific approaches to satisfying Paragraph 5 may vary between utilities.

Slide 7

Scenario 5 (SR Met, RLA Not Valid)

Cycle N-1 S/RV As-Found Test Results 2 S/RVs test at +2 9 S/RVs test at +6 SR Completion Steps:

Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)

Paragraph 3.ii - Satisfied (for N-1)

Paragraph 4 - Performed Paragraph 5 - SR Not Met (for N)

- Update the standard set of assumed S/RV lift setpoints to consider the results of as-found Cycle N-1 S/RV testing

- Use the updated set of standard S/RV setpoints as input to an updated Cycle N RLA

- The updated Cycle N RLA can not confirm that the SR will be met at end of Cycle N SR MET for Cycle N-1, Valid Cycle N RLA NOT Obtained Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1318 psig

> 1270 psig RLA

< Safety Limit SR MET Cycle N SR Between Performance Evaluation Requires RLA Update Explicit RLA Update Re-analysis Assumes: 11 S/RVs set at +6 psi (updated standard set of S/RV setpoints)

Yields: 1340 psig, >1325 psig SL Update Standard Set of Assumed S/RV Lift Setpoints used in RLAs Explicit Cycle N-1 Re-analysis of:

11 S/RVs set at +6 psi (considers Cycle N-1 as-found results)

Yields: 1320 psig, >1318 psig Thus: Conservative for Generic Use Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 8

Scenario 6 (SR NOT Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results 2 S/RVs test at +2 9 S/RVs test at +6 SR Completion Steps:

Paragraph 1 - Not Satisfied Paragraph 2 - Performed Paragraph 3.i - Not Satisfied (for N)

Paragraph 3.ii - SR Not Met (for N-1)

(Cycle N-1 re-analysis shows that Cycle N-1 overpressure analysis performed with S/RV setpoints at as-found values is > SL)

Paragraph 4 - Performed Paragraph 5 - Satisfied (for N)

(standard setpoint input assumptions revised to consider Cycle N-1 testing, used to produce updated Cycle N RLA, and confirms the SL is satisfied for Cycle N due to a less severe Cycle N core design)

SR NOT Met* for Cycle N-1, Valid Updated Cycle N RLA Obtained Cycle N-1 SR Evaluation Explicit Re-analysis performed Assumes: Cycle N-1 As-Found Yields: 1328 psig

> 1280 psig RLA

> Safety Limit SR NOT MET Cycle N SR Between Performance Evaluation Requires RLA Update Explicit RLA Update Re-analysis Assumes: 11 S/RVs set at +6 psi (updated standard set of S/RV setpoints)

Yields: 1320 psig, <1325 psig SL Update Standard Set of Assumed S/RV Lift Setpoints used in RLAs Explicit Cycle N-1 Re-analysis of:

11 S/RVs set at +6 psi (considers Cycle N-1 as-found results)

Yields: 1330 psig, >1328 psig Thus: Conservative for Generic Use Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1280 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Slide 9 Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

  • More detailed operability assessments for Cycle N-1 may be able to show SR was met. The approach shown here assumes only NRC approved methodologies for cycle OP RLA analyses are utilized.

Scenario 7 (SR Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results 8 S/RV test at +2 2 S/RVs test at -6 (below +/-3 ASME tolerance)

SR Completion Steps:

Paragraph 1 - Satisfied (for N & N-1)

(Cycle N-1 test results are all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 and Cycle N RLAs for the purposes of the overpressure analysis,* thus both RLAs remains bounding )

SR MET for Cycle N-1, Cycle N RLA is Valid

  • However, due to valves opening below allowable set pressure, overall potential impacts to other analyses due to the valves which opened below the ASME testing tolerance would be evaluated through the utilitys corrective action program Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed (theres no concern with Cycle N standard set of RLA inputs for the purpose of the overpressure analysis, as theyve been validated as conservative for Cycle N-1)

Cycle N SR Evaluation The standard set of RLA input assumptions are already more conservative than test results for the purpose of the overpressure analysis, so RLA results are bounding Satisfies SR for Cycle N-1 Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Cycle N (currently operating)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1290 psig < 1325 psig SL Slide 10 Cycle N Current S/RV Setpoints (not measurable during cycle operation; all as-left setpoints were within tolerance)

Scenario 8 (SR Met, RLA Valid)

Cycle N-1 S/RV As-Found Test Results (limited-scope valve testing) 5 of 11 total S/RVs tested:

4 S/RV test at +2 (within ASME tolerance) 1 S/RVs test at +6 (above ASME tolerance)

ASME code does not require further explicit testing of valves against +/-3 tolerance remaining 6 S/RVs assumed test result at +3 (top end of ASME tolerance)

SR Completion Steps:

Paragraph 1 - Satisfied (for N & N-1)

(The combination of the Cycle N-1 measured test results and assumed test results allowed per ASME code are all less limiting than the standard set of assumed S/RV lift setpoints which support the Cycle N-1 and Cycle N RLAs, thus both RLAs remains bounding)

SR MET for Cycle N-1, Cycle N RLA is Valid Cycle N SR Evaluation 4 S/RV test at +2 and 6 S/RV assumed test result at +3 are bounded by RLA assumed 10 S/RV at +4 psi 1 S/RV test at +6 is bounded by RLA assumed 1 SRVOOS

==

Conclusion:==

the assumed S/RV lift setpoints input to the RLA are already more conservative than test results Thus, the existing Cycle N-1 RLA SL confirmation analysis is bounding Satisfies SR for N-1 Cycle N-1 (operation complete)

RLA:

Assumes: 10 S/RVs set at +4 psi and 1 SRVOOS Yields: 1270 psig < 1325 psig SL Slide 11 Cycle N SR Between Performance Evaluation Explicit Evaluation Not Needed

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