CP-202300474, (Cpnpp), Application to Revise Technical Specifications to Adopt TSTF-591, Revise Risk Informed Completion Time (RICT) Program
| ML24059A390 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 02/28/2024 |
| From: | John Lloyd Luminant, Vistra Operations Company |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| CP-202300474, TXX-23078 | |
| Download: ML24059A390 (1) | |
Text
CP-202300474 TXX-23078 February 28, 2024 ATTN: Document Control Desk Ref 10 CFR 50.90 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Comanche Peak Nuclear Power Plant (CPNPP)
Docket Nos. 50-445 and 50-446 Application to Revise Technical Specifications to Adopt TSTF-591, "Revise Risk Informed Completion Time (RICT) Program"
Dear Sir or Madam:
Pursuant to 10 CFR 50.90, Vistra Operations Company LLC (Vistra OpCo) is submitting a request for an amendment to the Technical Specifications (TS) for Comanche Peak Nuclear Power Plant (CPNPP),
Units 1 and 2.
Vistra OpCo requests adoption of TSTF-591, "Revise Risk Informed Completion Time (RICT)
Program," which is an approved change to the Standard Technical Specifications (STS), into the CPNPP Units 1 and 2 TS. TSTF-591 revises the Technical Specifications (TS) Section 5.5 Program, "Risk Informed Completion Time Program," to reference Regulatory Guide (RG) 1.200, Revision 3, instead of Revision 2, and to make other changes. A new report is added to TS Section 5.6, "Reporting Requirements," to inform the NRC of newly developed methods used to calculate a RICT.
The enclosure provides a description and assessment of the proposed changes. Attachment 1 provides the existing TS pages marked to show the proposed changes. Attachment 2 provides revised (clean) TS pages. The proposed change does not affect the TS Bases.
Vistra OpCo requests that the amendment be reviewed under the Consolidated Line Item Improvement Process (CLIIP). Approval of the proposed amendment is requested within 6 months of completion of the NRCs acceptance review. Once approved, the amendment shall be implemented within 90 days.
In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated State Official.
This communication contains no new commitments regarding CPNPP Units 1 and 2.
Should you have any questions, please contact Nic Boehmisch at (254) 897-5064 or nicholas.boehmisch@luminant.com.
Jay J. Lloyd Senior Director, Engineering & Regulatory Affairs Comanche Peak Nuclear Power Plant (Vistra Operations Company LLC)
P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T
254.897.5337
TXX-23078 Page 2 of 2 I state under penalty of perjury that the foregoing is true and correct.
Executed on February 28, 2024.
Sincerely, Jay Uoy
2 CST)
Jay J. Lloyd
Enclosure:
Description and Assessment Attachments:
- 1. Proposed Technical Specification Changes (Mark-Up)
- 2. Revised Technical Specification Pages c (email) -
John Monninger, Region IV Uohn.Monninger@mc.gov]
Samson Lee, NRR [Samson.Lee@mc.gov]
John Ellegood, Senior Resident Inspector, CPNPP Uohn.Ellegood@mc.gov]
Hemy Strittmatter, Resident Inspector, CPNPP [Hemy.Strittmatter@mc.gov]
Mr. Robert Free [robert.free@dshs.state.tx.us]
Environmental Monitoring & Emergency Response Manager Texas Department of State Health Services Mail Code 1986 P. 0. Box 149347 Austin TX, 78714-9347
Enclosure to TXX-23078 Page 1 of 3 DESCRIPTION AND ASSESSMENT
1.0 DESCRIPTION
Vistra Operations Company LLC (Vistra OpCo) requests adoption of TSTF-591, "Revise Risk Informed Completion Time (RICT) Program," which is an approved change to the Standard Technical Specifications (STS), into the Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2 TS. TSTF-591 revises the Technical Specifications (TS) Section 5.5 Program, "Risk Informed Completion Time Program," to reference Regulatory Guide (RG) 1.200, Revision 3, instead of Revision 2, and to make other changes. A new report is added to TS Section 5.6, "Reporting Requirements," to inform the NRC of newly developed methods used to calculate a RICT.
2.0 ASSESSMENT
2.1 Applicability of Safety Evaluation Vistra OpCo has reviewed the safety evaluation for TSTF-591 provided to the Technical Specifications Task Force in a letter dated September 21, 2023. This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-591. Vistra OpCo has concluded that the justifications presented in TSTF-591 and the safety evaluation prepared by the NRC staff are applicable to Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2, and justify this amendment for the incorporation of the changes to the CPNPP TS.
2.2 Variations Vistra OpCo is proposing the following variations from the TS changes described in TSTF-591 or the applicable parts of the NRC staffs safety evaluation:
The CPNPP TS utilize different numbering than the STS on which TSTF-591 was based.
Specifically, the CPNPP Risk Informed Completion Time Program TS number is 5.5.23 which is different than the TSTF-591 numbering of 5.5.20. Additionally, the new CPNPP Risk Informed Completion Time (RICT) Program Upgrade Report TS will be numbered 5.6.10 which is different than the TSTF-591 numbering of 5.6.8. These differences are administrative and do not affect the applicability of TSTF-591 to the CPNPP TS.
The CPNPP Risk Informed Completion Time Program, Paragraph e, is different from the TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," wording used as the starting point in TSTF-591. These differences do not affect the applicability of the proposed change.
3.0 REGULATORY ANALYSIS
3.1 No Significant Hazards Consideration Analysis Vistra OpCo requests adoption of TSTF-591, "Revise Risk Informed Completion Time (RICT)
Program," which is an approved change to the Standard Technical Specifications (STS), into the
Enclosure to TXX-23078 Page 2 of 3 Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2 Technical Specifications (TS).
TSTF-591 revises the Technical Specifications (TS) Section 5.5 Program, "Risk Informed Completion Time Program," to reference Regulatory Guide (RG) 1.200, Revision 3, instead of Revision 2, and to make other changes. A new report is added to TS Section 5.6, "Reporting Requirements," to inform the NRC of newly developed methods used to calculate a RICT.
Vistra OpCo has evaluated if a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
- 1.
Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change updates the standard for maintaining and updating PRA models used to calculate a RICT from NRC-approved Regulatory Guide 1.200, Revision 2, to NRC-approved Regulatory Guide 1.200, Revision 3. A new report is added to inform the NRC when a newly developed method is used.
The proposed change does not involve a significant increase in the probability of an accident previously evaluated because the change involves no change to the plant or its modes of operation. The proposed change does not increase the consequences of an accident because the design-basis mitigation function of the affected systems is not changed and the consequences of an accident during the extended Risk Informed Completion Time are no different from those during the existing Completion Time. The submittal of information-only reports has no effect on the initiators or consequences of any accidents previously evaluated Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2.
Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change updates the standard for maintaining and updating PRA models used to calculate a RICT from NRC-approved Regulatory Guide 1.200, Revision 2, to NRC-approved Regulatory Guide 1.200, Revision 3. A new report is added to inform the NRC when a newly developed method is used.
The proposed change does not change a design function or method of operation of the plant. The proposed change does not involve a physical alteration of the plant (no new or different kind of equipment will be installed).
Enclosure to TXX-23078 Page 3 of 3 Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3.
Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No The proposed change updates the standard for maintaining and updating PRA models used to calculate a RICT from NRC-approved Regulatory Guide 1.200, Revision 2, to NRC-approved Regulatory Guide 1.200, Revision 3. A new report is added to inform the NRC when a newly developed method is used.
The proposed change supports the extension of Completion Times provided risk is assessed and managed in accordance with the NRC-approved RICT Program. The proposed change does not alter any design basis or safety limits. The proposed change affects the standard used to maintain the PRA models used in the RICT Program by changing from one NRC-approved standard to a later NRC-approved version and requiring submittal of an information-only report. The RICT Program will continue to assure that adequate margins of safety are maintained.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, Vistra OpCo concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.
3.2 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
4.0 ENVIRONMENTAL CONSIDERATION
A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
to TXX-23078 Proposed Technical Specification Changes (Mark-up)
Programs and Manuals 5.5 5.5 Programs and Manuals COMANCHE PEAK - UNITS 1 AND 2 5.5-18 5.5.23 Risk Informed Completion Time Program This program provides controls to calculate a Risk Informed Completion Time (RICT) and must be implemented in accordance with NEI 06-09-A, Revision 0, "Risk-Managed Technical Specifications (RMTS) Guidelines." The program shall include the following:
a.
The RICT may not exceed 30 days; b.
A RICT may only be utilized in MODE 1 and 2; c.
When a RICT is being used, any change to the plant configuration, as defined in NEI 06-09-A, Appendix A, must be considered for the effect on the RICT.
1.
For planned changes, the revised RICT must be determined prior to implementation of the change in configuration.
2.
For emergent conditions, the revised RICT must be determined within the time limits of the Required Action Completion Time (i.e., not the RICT) or 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after the plant configuration change, whichever is less.
3.
Revising the RICT is not required if the plant configuration change would lower plant risk and would result in a longer RICT.
d.
For emergent conditions, if the extent of condition evaluation for inoperable structures, systems, or components (SSCs) is not complete prior to exceeding the Completion Time, the RICT shall account for the increased possibility of common cause failure (CCF) by either:
1.
Numerically accounting for the increased possibility of CCF in the RICT calculation; or 2.
Risk Management Actions (RMAs) not already credited in the RICT calculation shall be implemented that support redundant or diverse SSCs that perform the function(s) of the inoperable SSCs, and, if practicable, reduce the frequency of initiating events that challenge the function(s) performed by the inoperable SSCs.
Amendment No. 183 No Changes. For Information Only.
Programs and Manuals 5.5 5.5 Programs and Manuals COMANCHE PEAK - UNITS 1 AND 2 5.5-19 5.5.23 Risk Informed Completion Time Program (continued)
Amendment No. 183 e.
The risk assessment approaches and methods shall be acceptable to the NRC. The plant PRA shall be based on the as-built, as-operated, and maintained plant; and reflect the operating experience at the plant, as specified in Regulatory Guide 1.200, Revision 2. Methods to assess the risk from extending the Completion Times must be PRA methods approved for use with this program, or other methods approved by the NRC for generic use; and any change in the PRA methods to assess risk that are outside these approval boundaries require prior NRC approval.
e.
A RICT calculation must include the following hazard groups: Internal flood and internal events PRA model, internal fire PRA model, seismic penalty factor, and extreme winds and tornado penalty factor. Changes to these means of assessing the hazard groups require prior NRC approval.
f.
The PRA models used to calculate a RICT shall be maintained and upgraded in accordance with the processes endorsed in the regulatory positions of Regulatory Guide 1.200, Revision 3, "Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities."
g.
A report shall be submitted in accordance with Specification 5.6.10 before a newly developed method is used to calculate a RICT.
Reporting Requirements 5.6 5.6 Reporting Requirements COMANCHE PEAK - UNITS 1 AND 2 5.6-6 5.6.9 Steam Generator Tube Inspection Report (continued) d.
An analysis summary of the tube integrity conditions predicted to exist at the next scheduled inspection (the forward-looking tube integrity assessment) relative to the applicable performance criteria, including the analysis methodology, inputs, and results; e.
The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG; f.
The results of any SG secondary side inspections; g.
For Unit 2, the primary to secondary leakage rate observed in each SG (if it is not practical to assign the leakage to an individual SG, the entire primary to secondary leakage should be conservatively assumed to be from one SG) during the cycle preceding the inspection which is the subject of the report; h.
For Unit 2, the calculated accident induced leakage rate from the portion of the tubes below 14.01 inches from the top of the tubesheet for the most limiting accident in the most limiting SG. In addition, if the calculated accident induced leakage rate from the most limiting accident is less than 3.16 times the maximum operational primary to secondary leakage rate, the report should describe how it was determined; and i.
For Unit 2, the results of monitoring for tube axial displacement (slippage). If slippage is discovered, the implications of the discovery and corrective action shall be provided.
Amendment No. 158, 182 Risk Informed Completion Time (RICT) Program Upgrade Report A report describing newly developed methods and their implementation must be submitted following a probabilistic risk assessment (PRA) upgrade associated with newly developed methods and prior to using those methods to calculate a RICT. The report shall include:
a.
The PRA models upgraded to include newly developed methods; b.
A description of the acceptability of the newly developed methods consistent with Section 5.2 of PWROG-19027-NP, Revision 2, "Newly Developed Method Requirements and Peer Review;"
c.
Any open findings from the peer-review of the implementation of the newly developed methods and how those findings were dispositioned; and d.
All changes to key assumptions related to newly developed methods or their implementation.
5.6.10
to TXX-23078 Revised Technical Specification Changes
Programs and Manuals 5.5 5.5 Programs and Manuals COMANCHE PEAK - UNITS 1 AND 2 5.5-18 5.5.23 Risk Informed Completion Time Program This program provides controls to calculate a Risk Informed Completion Time (RICT) and must be implemented in accordance with NEI 06-09-A, Revision 0, "Risk-Managed Technical Specifications (RMTS) Guidelines." The program shall include the following:
a.
The RICT may not exceed 30 days; b.
A RICT may only be utilized in MODE 1 and 2; c.
When a RICT is being used, any change to the plant configuration, as defined in NEI 06-09-A, Appendix A, must be considered for the effect on the RICT.
1.
For planned changes, the revised RICT must be determined prior to implementation of the change in configuration.
2.
For emergent conditions, the revised RICT must be determined within the time limits of the Required Action Completion Time (i.e., not the RICT) or 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after the plant configuration change, whichever is less.
3.
Revising the RICT is not required if the plant configuration change would lower plant risk and would result in a longer RICT.
d.
For emergent conditions, if the extent of condition evaluation for inoperable structures, systems, or components (SSCs) is not complete prior to exceeding the Completion Time, the RICT shall account for the increased possibility of common cause failure (CCF) by either:
1.
Numerically accounting for the increased possibility of CCF in the RICT calculation; or 2.
Risk Management Actions (RMAs) not already credited in the RICT calculation shall be implemented that support redundant or diverse SSCs that perform the function(s) of the inoperable SSCs, and, if practicable, reduce the frequency of initiating events that challenge the function(s) performed by the inoperable SSCs.
Amendment No. 183 No Changes. For Information Only.
Programs and Manuals 5.5 5.5 Programs and Manuals COMANCHE PEAK - UNITS 1 AND 2 5.5-19 5.5.23 Risk Informed Completion Time Program (continued)
Amendment No. 183
- e.
A RICT calculation must include the following hazard groups: Internal flood and internal events PRA model, internal fire PRA model, seismic penalty factor, and extreme winds and tornado penalty factor. Changes to these means of assessing the hazard groups require prior NRC approval.
- f.
The PRA models used to calculate a RICT shall be maintained and upgraded in accordance with the processes endorsed in the regulatory positions of Regulatory Guide 1.200, Revision 3, "Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities."
- g.
A report shall be submitted in accordance with Specification 5.6.10 before a newly developed method is used to calculate a RICT.
Reporting Requirements 5.6 5.6 Reporting Requirements COMANCHE PEAK - UNITS 1 AND 2 5.6-6 5.6.9 Steam Generator Tube Inspection Report (continued) d.
An analysis summary of the tube integrity conditions predicted to exist at the next scheduled inspection (the forward-looking tube integrity assessment) relative to the applicable performance criteria, including the analysis methodology, inputs, and results; e.
The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG; f.
The results of any SG secondary side inspections; g.
For Unit 2, the primary to secondary leakage rate observed in each SG (if it is not practical to assign the leakage to an individual SG, the entire primary to secondary leakage should be conservatively assumed to be from one SG) during the cycle preceding the inspection which is the subject of the report; h.
For Unit 2, the calculated accident induced leakage rate from the portion of the tubes below 14.01 inches from the top of the tubesheet for the most limiting accident in the most limiting SG. In addition, if the calculated accident induced leakage rate from the most limiting accident is less than 3.16 times the maximum operational primary to secondary leakage rate, the report should describe how it was determined; and i.
For Unit 2, the results of monitoring for tube axial displacement (slippage). If slippage is discovered, the implications of the discovery and corrective action shall be provided.
Amendment No. 158, 182 Risk Informed Completion Time (RICT) Program Upgrade Report A report describing newly developed methods and their implementation must be submitted following a probabilistic risk assessment (PRA) upgrade associated with newly developed methods and prior to using those methods to calculate a RICT. The report shall include:
a.
The PRA models upgraded to include newly developed methods; b.
A description of the acceptability of the newly developed methods consistent with Section 5.2 of PWROG-19027-NP, Revision 2, "Newly Developed Method Requirements and Peer Review;"
c.
Any open findings from the peer-review of the implementation of the newly developed methods and how those findings were dispositioned; and d.
All changes to key assumptions related to newly developed methods or their implementation.
5.6.10