ML24081A046
| ML24081A046 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 03/22/2024 |
| From: | Samson Lee Plant Licensing Branch IV |
| To: | Gerfen P Pacific Gas & Electric Co |
| Lee S, 301-415-3158 | |
| References | |
| EPID L-2023-LLA-0100 | |
| Download: ML24081A046 (1) | |
Text
March 22, 2024 Paula Gerfen Senior Vice President, Generation and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 56, Mail Code 104/6 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON NUCLEAR POWER PLANT, UNITS 1 AND 2 - AUDIT
SUMMARY
IN SUPPORT OF LICENSE AMENDMENT REQUEST TO ADOPT TSTF-505, REVISION 2, PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES - RITSTF INITIATIVE 4b (EPID L-2023-LLA-0100)
Dear Paula Gerfen:
By letter dated July 13, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23194A228), Pacific Gas and Electric Company (the licensee) submitted a license amendment request for Diablo Canyon Nuclear Power Plant, Units 1 and 2, to adopt Technical Specifications Task Force (TSTF) Traveler TSTF-505, Revision 2, Provide Risk Informed Extended Completion Times - RITSTF [Risk-Informed TSTF] Initiative 4b to permit the use of risk-informed technical specification completion times for certain actions required when limiting conditions for operation are not met.
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the licensee's submittal and determined that a regulatory audit would assist in the timely completion of the licensing review process. The NRC staff issued the regulatory audit plan on September 21, 2023 (ML23264A001).
The NRC staff conducted the regulatory audit from November 16, 2023, to January 15, 2024.
The results of the regulatory audit will be used by the NRC staff to finalize requests for additional information.
The audit summary report is provided as an enclosure to this letter.
If you have any questions, please contact me at (301) 415-3168 or via email at Samson.Lee@nrc.gov.
Sincerely,
/RA/
Samson S. Lee, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323
Enclosure:
Audit Summary cc: Listserv
Enclosure OFFICE OF NUCLEAR REACTOR REGULATION REGULATORY AUDIT
SUMMARY
IN SUPPORT OF LICENSE AMENDMENT TO ADOPT TSTF-505, REVISION 2 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON NUCLEAR POWER PLANT, UNITS 1 AND 2 DOCKET NOS. 50-275 AND 50-323
1.0 INTRODUCTION
By letter dated July 13, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23194A228), Pacific Gas and Electric Company (the licensee) submitted a license amendment request (LAR) for Diablo Canyon Nuclear Power Plant, Units 1 and 2 (Diablo Canyon or DCPP), to adopt Technical Specifications Task Force (TSTF)
Traveler TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF
[Risk-Informed TSTF] Initiative 4b, to permit the use of risk-informed technical specification (TS) completion times (CTs) for certain actions required when limiting conditions for operation (LCOs) are not met.
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the licensee's submittal and determined that a regulatory audit would assist in the timely completion of the licensing review process. The NRC staff issued the regulatory audit plan on September 21, 2023 (ML23264A001), which detailed the logistics, scheduling and audit request items in the audit plans enclosure.
The NRC staff conducted the regulatory audit from November 16, 2023, to January 15, 2024.
The regulatory audit allowed the staff to clarify its understanding of the LAR and to identify additional information required to complete its safety evaluation.
The regulatory audit was performed consistent with NRC Office of Nuclear Reactor Regulation Office Instruction LIC-111, Revision 1, Regulatory Audits, dated October 31, 2019 (ML19226A274).
2.0 AUDIT ACTIVITIES AND OBSERVATIONS The NRC audit team consisted of NRC staff. Section 3.0 of this audit summary lists the individuals who took part in or attended the audit.
The NRC project manager discussed the audit plan, its logistics and scheduled the regulatory audit with the licensee. The regulatory audit was conducted from November 16, 2023, to January 15, 2024. Throughout the audit period, the NRC audit team used an internet-based portal provided by the licensee to review information related to the application, primarily information that was not docketed. Formal audit meetings with the licensee were held from December 11 to 13, 2023, to facilitate technical discussions of audit questions according to the audit plan.
Technical discussions were focused on the following major areas: probabilistic risk assessment (PRA), external hazards, TSs, and electrical engineering. Detailed topics of seismic risk contribution analysis, extreme wind analysis, high wind PRA acceptability, TS LCOs, scope, equipment performance monitoring, open-phased condition, and screening of other external hazards were also discussed.
On December 13, 2023, the NRC staff provided a brief conclusion of the formal audit meetings including audit objectives that were met and details on the path forward. There were no open items from the audit discussions. Documents that were provided as part of the audit that were reviewed by the NRC staff are listed in section 4.0 of this audit summary. During the December 13, 2023, discussion, the licensee committed to submit a supplement to the LAR to provide additional information on the docket.
The licensee submitted a supplement to the LAR on January 15, 2024 (ML24016A299), which details the technical discussion points made above and the additional information provided by the licensee on the docket. The NRC staff reviewed the licensees supplement to assess if any additional information was needed and determined that no additional information would be needed to complete its review of the LAR post the supplement.
3.0 AUDIT PARTICIPANTS NRC Audit Team Name Organization Steven Alferink PRA Licensing Branch C Mihaela Biro PRA Licensing Branch A Michael Breach Mechanical Engineering & Inservice Testing Branch Norbert Carte Instrumentation and Controls Branch Jeff Circle PRA Licensing Branch A Robert Elliott Technical Specifications Branch Fred Forsaty Nuclear Systems Performance Branch David Gennardo PRA Licensing Branch A Ed Kleeh Electrical Engineering Branch Hari Kodali Electrical Engineering Branch Malcolm Patterson PRA Licensing Branch A (Technical Lead)
Derek Scully Containment and Plant Systems Branch Hanry Wagage Containment and Plant Systems Branch Zeechung Wang Performance and Reliability Branch Khadijah West Technical Specifications Branch Name Organization Steve Wyman Electrical Engineering Branch 4.0 DOCUMENTS REVIEWED The licensee provided an extensive list of supporting documents (e.g., analyses, calculations, reports, drawings, and procedures) on the document portal available during the audit period.
Below lists the documents available on the portal that the NRC audit team reviewed during the audit.
Application Specific Document Pacific Gas and Electric Company, Diablo Canyon Power Plant, Probabilistic Risk Assessment, Calculation PRA 23-01, Revision 0, Documentation of the Quantification of Sample RICTs [Risk Informed Completion Times] Provided in the Risk Managed Technical Specification LAR, July 3, 2023.
PRA Documents Westinghouse letter, LTR-RAM-II-13-002, RG [Regulatory Guide] 1.200 PRA Peer Review Against the ASME/ANS [American Society of Mechanical Engineers / American Nuclear Society] PRA Standard Requirements for the Diablo Canyon Nuclear Plant Probabilistic Risk Assessment, Westinghouse Proprietary Class 2, March 20, 2013.
Diablo Canyon Power Plant, Administrative Work Procedure AWP E-028, Revision 6, PRA Model Maintenance and Upgrades, November 16, 2021.
Pacific Gas and Electric Company, Diablo Canyon Power Plant, Probabilistic Risk Assessment, Calculation File No. B.1 Revision 2, PRA Notebook, May 22, 2023.
Pressurized Water Reactor Owners Group, PWROG-23015-P, Revision 0, Diablo Canyon F&O
[Fact and Observation] Closure and Focused Scope Peer Review Report, Westinghouse Proprietary Class 2, July 2023.
Pacific Gas and Electric Company, Diablo Canyon Power Plant, Probabilistic Risk Assessment, Calculation PRA C.10 Revision 11, DCPP PRA Model Technical Adequacy, September 27, 2023.
Seismic PRA Pacific Gas and Electric Company, Probabilistic Risk Assessment, Calculation File No. F.6 Revision 5, Diablo Canyon Seismic Models, February 21, 2006.
Pressurized Water Reactor Owners Group, PWROG-17022-P, Revision 0, Peer Review of the Diablo Canyon Units 1 & 2 Seismic Probabilistic Risk Assessment, Westinghouse Proprietary Class 2, September 2017.
Pressurized Water Reactor Owners Group, PWROG-17078-P, Revision 0, Independent Assessment of Facts & Observations Closure and Focused Scope Peer Review of the Diablo Canyon Units 1 & 2 Seismic Probabilistic Risk Assessment, Westinghouse Proprietary Class 2, March 2018.
Electric Power Research Institute, Technical Report 3002020744, Investigation of Seismic Probabilistic Risk Assessment (SPRA) Quantification to Simplify PRA Models Used to Assess Risk-Informed Completion Times, June 2021.
Fire PRA Westinghouse letter, LTR-RAM-II-08-019, Pilot Application of the Fire PRA Peer Review Process for the Diablo Canyon Power Plant Fire Probabilistic Risk Assessment, Westinghouse Proprietary Class 2, October 17, 2008.
Westinghouse letter, LTR-RAM-II-11-004, Fire PRA Peer Review Against the Fire PRA Standard Supporting Requirements from Section 4 of the ASME/ANS Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessments for Nuclear Power Plant Applications for the Diablo Canyon Plant Fire Probabilistic Risk Assessment, Westinghouse Proprietary Class 2, May 24, 2011.
Engineering Planning and Management, Inc., P3118-004-001, Revision 0, F&O Closeout by Independent Assessment Report for the Diablo Canyon Nuclear Power Plant (DCPP) Fire PRA Model, Against the 2009 ASME PRA Standard Requirements and NEI [Nuclear Energy Institute]
05-04 Appendix X, September 2018.
External Hazards Pacific Gas and Electric Company, Methodology for Probabilistic Tsunami Hazard Analysis:
Trial Application for the Diablo Canyon Power Plant Site, April 9, 2010.
Pacific Gas and Electric Company, Diablo Canyon Power Plant, Probabilistic Risk Assessment, Calculation File No. X.1 Revision 1, DCPP Other External Events, November 22, 2016.
Electric Power Research Institute, Technical Report 3002018232, High Wind Loss of Offsite Power Durations and Recovery, October 2020.
Updated Final Safety Analysis Report (UFSAR)
Figures 8.3-16-1, 8.3-16-2, 8.3-16-3, 8.3-3.1, 8.3-17-1, and 8.3-17-2.
- concurrence via email OFFICE NRR/DORL/LPL4/PM*
NRR/DORL/LPL4/LA*
NRR/DRA/APLA/BC*
NAME SLee PBlechman BPascarelli DATE 3/21/2024 3/22/2024 3/20/2024 OFFICE NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME JRankin SLee DATE 3/22/2024 3/22/2024