ML25078A268

Summary of Technical Discussion on EPRIs Draft Responses to NRC Staff Issued Request for Additional Information for EPRI Report 3002025288, Enhanced Risk-Informed Categorization Methodology for Pressure Boundary Components

ML25078A268
Person / Time
Site:	Electric Power Research Institute
Issue date:	04/29/2025
From:	Lois James Licensing Processes Branch
To:	Jennivine Rankin Licensing Processes Branch
References
EPRI TR 3002025288, EPID L-2023-TOP-0031 pre-app, EPID L-2023-TOP-0045 pre-fee, EPID L-2023-NTR-0008 post-fee
Download: ML25078A268 (7)

Text

April 29, 2025 MEMORANDUM TO:

Jennie Rankin, Acting Chief Licensing Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:

Lois M. James, Senior Project Manager /RA/

Licensing Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUMMARY

OF TECHNICAL DISCUSSION ON ELECTRIC POWER RESEARCH INSTITUTES DRAFT RESPONSES TO U.S. NUCLEAR REGULATORY COMMISSION STAFF ISSUED REQUEST FOR ADDITIONAL INFORMATION FOR ELECTRIC POWER RESEARCH INSTITUTE REPORT 3002025288, ENHANCED RISK-INFORMED CATEGORIZATION METHODOLOGY FOR PRESSURE BOUNDARY COMPONENTS (EPID NO. L-2023-NTR-0008)

On April 8, 2025, the U.S. Nuclear Regulatory Commission (NRC) staff met with Electric Power Research Institute (EPRI) to discuss of EPRIs draft responses to NRC staff issued request for additional information for EPRI Report 3002025288, Enhanced Risk-Informed Categorization Methodology for Pressure Boundary Components. The meeting summary is Enclosure 1, and the list of attendees is Enclosure 2.

If you have any questions or comments, please contact me via e-mail at Lois.James@nrc.gov.

Docket No. 9902021

Enclosures:

1. Meeting Summary

2. List of Attendees CONTACT: Lois M. James, NRR/DORL/LLPB 301-415-3306

U.S. Nuclear Regulatory Commission Public Meeting Summary

SUMMARY

OF TECHNICAL DISCUSSION ON ELECTRIC POWER RESEARCH INSTITUTES DRAFT RESPONSES TO U.S. NUCLEAR REGULATORY COMMISSION STAFF ISSUED REQUEST FOR ADDITIONAL INFORMATION FOR ELECTRIC POWER RESEARCH INSTITUTE REPORT 3002025288, ENHANCED RISK-INFORMED CATEGORIZATION METHODOLOGY FOR PRESSURE BOUNDARY COMPONENTS (EPID NO. L-2023-NTR-0008)

Date of Meeting: April 8, 2025, 1:00 pm - 5:00 pm Location:

Hybrid Type of Meeting: This was an Observation Meeting in which attendees were given an opportunity to observe the U.S. Nuclear Regulatory Commission (NRC) performing its regulatory function or discussing regulatory issues. Attendees had an opportunity to ask questions of the NRC staff or make comments about the issues discussed following the business portion of the meeting; however, the NRC is not actively soliciting comments toward regulatory decisions at this meeting.

Purpose of the Meeting: To discuss Electric Power Research Institutes (EPRIs) draft responses to NRC staff issued request for additional information (RAI) for EPRI Report 3002025288, Enhanced Risk-Informed Categorization Methodology for Pressure Boundary Components (topical report or TR).

General Details: The NRC staff held a public, observational meeting with EPRI to discuss EPRIs draft responses to NRC staff issued RAIs for EPRI Report 3002025288. The meeting began at 1:00 pm and ended at 1:45 pm. There were seventeen NRC staff, four EPRI representatives and contractor, seven industry representatives, and three members of the public. The meeting began with introductions of the NRC staff and EPRI representatives.

Summary of Meeting:

The NRC staff led the discussion of each RAI response. The NRC RAIs can be found in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML24352A481. The EPRI draft RAI responses discussed at the April 8, 2025, public meeting can be found at ADAMS Accession No. ML25091A093.

NRC RAI No.

Discussion RAI 01 - Accounting for High Consequence Scenarios The NRC staff stated that, in general, the edits, changes and rewording, especially for this RAI, were very helpful. The NRC staff further stated there was one outstanding question regarding the information provided. Specifically, how much of the RAI response will be incorporated into the TR to ensure consistent implementation?

The Nuclear Energy Institute (NEI) representative stated that the process for procurement exist and are in industry process. The NEI representative further stated that duplication would not be good

NRC RAI No.

Discussion for consistency and asked if referencing the information be sufficient?

The NRC staff agreed that reference could be sufficient if the industry documents were available for reference.

The EPRI representative agreed to summarize the RAI response in the TR and provide the reference to the industry guidance, not duplicate information.

RAI 02 - SSC Categorization as a Single Plant Unit For RAI 2, the NRC staff noted one item - the use of the words the whole plant. This appears to be the same as a single system encompasses all passive component. Can EPRI discuss?

The EPRI representative clarified that the TR provides guidance on categorizing the entire pressure boundary system as one system, with notes on how this will be worked through the analysis. EPRI asked if the NRC was concerned with the introduction of the term the whole plant?

The NRC staff stated that the new words were the concern and sought clarification.

The EPRI representatives stated they understood the question and will clarify the terminology For RAI 2b through RAI 2e, the NRC staff did not have any comments or questions.

RAI 03 - Addressing Uncertainty and Other Events in Individual Assessments For RAI 3a and RAI 3b, the NRC staff did not have any comments or questions.

For RAI 3c, the EPRI representative referenced Section 6 of the TR, Attachment A (Supplemental Information Related to the Enhanced Risk Informed Categorizing Methodology for Pressure Boundary Components, EPRI Technical Report 3002025288, dated June 2023), and NEI 00-04 where defense-in-depth is addressed in the methodology. The NRC staff did not have any further comments or questions.

For RAI 3d and RAI 3e, the NRC staff did not have any comments or questions.

RAI Qualitative Considerations for Shutdown Operations and External Events For RAI 4, the NRC staff did not have any comments or questions.

RAI 05 - Plant Design Scope for Methodology The NRC staff stated that they understood and agreed with the 1st sentence in the RAI response.

However, the NRC staff noted that the language to be added to the TR does not say precisely what

NRC RAI No.

Discussion is stated in the 1st sentence. Future new plants licensed under Title 10 of the Code of Federal Regulation Part 50, Domestic licensing of production and utilization facilities, could have very different structure than current operating fleet. The NRC staff further stated that previously operating plants and Watts Bar 2 would fit within the envelope of this TR. The NRC staff would appreciate it if EPRI made this clearer.

The EPRI representatives stated that they understood the question and would review and address it in the final submittal.

RAI 06 - Clarification for Required Prerequisite Programs to the Methodology For RAI 6a through RAI 6e, the NRC staff did not have any comments or questions.

RAI 07 - Reference to Industry Guidance for Quantitative Assessment The NRC staff did not have any comments or questions.

RAI 08 - Clarification of Reactor Coolant Boundary Categorization The NRC staff did not have any comments or questions.

RAI 09 - Sensitivity Calculation to Account for Uncertainty The NRC staff stated that the RAI response provided the information needed to resolve this RAI. The NRC staff noted that if approved, the sensitivity factor of 3 would be only applicable to this TR and not necessarily appropriate to future TR submittals.

The EPRI representatives stated that they understood that doing the analysis is the important part and not specifically the sensitivity factor of 3. The EPRI representatives stated that implementation of this TR should include a sensitive analysis consistent with NEI 00-04.

The NRC staff and EPRI representatives agreed that the RAI responses and a marked-up version of the TR would be submitted to the NRC by April 30, 2025.

Public Participation Themes:

No member of the public spoke on the webinar.

Action Items/Next Steps:

The NRC staff will prepare and issue a meeting summary.

Attachments:

Meeting description and agenda - ADAMS Accession No. ML25092A071 NRC RAIs - ADAMS Accession No. ML24352A481 EPRI Draft RAI Responses - ADAMS Accession No. ML25091A093

U.S. Nuclear Regulatory Commission Public Meeting - Attendees List April 8, 2025

SUMMARY

OF TECHNICAL DISCUSSION ON ELECTRIC POWER RESEARCH INSTITUTES DRAFT RESPONSES TO U.S. NUCLEAR REGULATORY COMMISSION STAFF ISSUED REQUEST FOR ADDITIONAL INFORMATION FOR ELECTRIC POWER RESEARCH INSTITUTE REPORT 3002025288, ENHANCED RISK-INFORMED CATEGORIZATION METHODOLOGY FOR PRESSURE BOUNDARY COMPONENTS (EPID NO. L-2023-NTR-0008)

Name U.S. Nuclear Regulatory Commission (NRC) Participants Mihaela Biro NRC Jeff Circle NRC Stephen Cumblidge NRC Carolyn Fairbanks NRC David Gennardo NRC Lois James NRC Meena Khanna NRC Matthew Mitchell NRC Demetrius Murray NRC Ching Ng NRC Bob Pascarelli NRC Jennie Rankin NRC Aida Rivera-Varona NRC Shilp Vasavada NRC Sunit Weerakkody NRC Dan Widrevitz NRC John Wise NRC EPRI Participants Name Affiliation Richard Fougerousse EPRI Doug Kull EPRI Ashley Lindeman EPRI Jim Moody EPRI Industry Participants Name Affiliation Sari Alkhatib Argonne National Laboratory Jana Bergman Curtiss Wright Rob Burg Engineering, Management, and Planning Inc. (EMP)

Chico Pellizzari EMP David Bidwell Jensen Hughes David Passehl Jensen Hughes Kelli Voelsing Nuclear Energy Institute

Public Participants Name Affiliation Lara Chern member of the public Brad Dolan member of the public York member of the public

ML25078A268

^via eConcurrence *via e-mail NRR-106 OFFICE DORL/LLPB/PM DORL/LLPB/LA DNRL/NPHP/BC DRA/APLA/BC NAME LJames^

DHarrison^

MMitchell^

BPascarelli^

DATE 04/17/2025 04/23/2025 04/23/2025 04/28/2025 OFFICE DORL/LLPB/BC DORL/LLPB/PM NAME JRankin (A)^

LJames^

DATE 04/29/2025 04/29/2025