ML24299A222

Audit Summary for License Amendment Request to Revise Renewed Facility Operating Licenses to Adopt an Alternative Seismic Method for Categorization of Structures, Systems, and Components

ML24299A222
Person / Time
Site:	Hatch
Issue date:	10/31/2024
From:	Dawnmathews Kalathiveettil Plant Licensing Branch II
To:	Coleman J Southern Nuclear Operating Co
Kalathiveettil, D
References
EPID L-2024-LLA-0017
Download: ML24299A222 (1)

Text

October 31, 2024

Jamie M. Coleman Regulatory Affairs Director Southern Nuclear Operating Co., Inc.

3535 Colonnade Parkway Birmingham, AL 35243

SUBJECT:

EDWIN I. HATCH NUCLEAR PLANT, UNITS 1 AND 2 - AUDIT

SUMMARY

FOR LICENSE AMENDMENT REQUEST TO REVISE RENEWED FACILITY OPERATING LICENSES TO ADOPT AN ALTERNATIVE SEISMIC METHOD FOR CATEGORIZATION OF STRUCTURES, SYSTEMS, AND COMPONENTS (EPID L-2024-LLA-0017)

Dear Jamie Coleman:

By letter dated February 20, 2024 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML24051A239), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2. The LAR proposes to modify the licensing basis to implement a change to the approved voluntary implementation of the provisions of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.69, Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors. The proposed amendment would incorporate the use of an alternative seismic method into the previously approved 10 CFR 50.69 categorization process in addition to the plant-specific Hatch seismic probabilistic risk assessment.

By letter dated June 14, 2024 (ML24163A053), the U.S. Nuclear Regulatory (NRC) staff issued an audit plan regarding SNCs LAR as part of the NRC staffs review.

To support its review, the NRC staff conducted a regulatory audit from July 1, through September 30, 2024. This was conducted virtually via Teams, using a licensee-established electronic portal available to NRC staff, with a formal audit meeting on July 10, 2024. The NRC staff reviewed documents and held discussions with members of SNC and its contractors. The regulatory audit summary is provided as an enclosure to this letter.

J. Coleman

If you have any questions, please contact me by telephone at (301) 415-5905 or by e-mail at Dawnmathews.Kalathiveettil@nrc.gov.

Sincerely,

/RA/

Dawnmathews Kalathiveettil, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket Nos. 50-321 and 50-366

Enclosure:

Audit Summary REGULATORY AUDIT

SUMMARY

BY THE OFFICE OF NUCLEAR REACTOR REGULATION

FOR THE LICENSE AMENDMENT REQUEST

TO REVISE THE LICENSING BASIS

TO ADOPT AN ALTERNATIVE SEISMIC METHOD FOR

CATEGORIZATION OF STRUCTURES, SYSTEMS, AND COMPONENTS

EDWIN I. HATCH NUCLEAR PLANT, UNITS 1 AND 2

SOUTHERN NUCLEAR OPERATING COMPANY

DOCKET NOS.: 50-321 AND 50-366

EPID NO: L-2024-LLA-0017

1.0 BACKGROUND

By letter dated February 20, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24051A239), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Edwin I. Hatch Nuclear Plant, Units 1 and 2 (Hatch). The proposed amendment modifies t he licensing basis to implement a change to the approved voluntary implementation of the provisions of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.69, Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors. The proposed amendment would incorporate the use of an alternative seismic method into the previously approved 10 CFR 50.69 categorization process in addition to the plant-specific Hatch seismic probabilistic risk assessment.

2.0 AUDIT SCOPE AND PURPOSE

By letter dated June 14, 2024 (ML24163A053), the U.S. Nuclear Regulatory (NRC) staff issued an audit plan regarding SNCs LAR as part of the NRC staffs review. The audit was conducted to meet the following objectives:

Clarification of Hatch plant-specific applicability and variations as compared to the LaSalle 10 CFR 50.69 precedent.

Consideration of licensee experience and results using the seismic PRA in the approved 10 CFR 50.69 categorization process.

Discussion on non-PRA-based qualitative assessments.

Identifying any information needed for NRC to assess whether proposed changes could challenge design-basis functions or adversely affect the capability or capacity of plant equipment to perform design-basis functions.

Enclosure

Identifying questions and information needs that may require formal requests for additional information (RAIs) per NRR Office Instruction LIC-115, Processing Requests for Additional Information (ML21141A238).

3.0 AUDIT LOGISTICS

The NRC staff conducted the regulatory audit from July 1, through September 30, 2024. This was conducted virtually via Teams, using a licensee-established electronic portal (Certrec) available to NRC staff. On July 10, 2024, NRC staff held a formal audit meeting with SNC staff, via Teams, to discuss the items provided in the Initial Audit Items List as well as the Audit Questions which were provided as Enclosures 2 and 3 respectively, to the letter dated June 14, 2024 (ML24163A053). The audit was conducted by members of the Office of Nuclear Reactor Regulation (NRR) including Dawnmathews Kalathiveettil, Project Manager for Hatch Units 1 and 2 in the Division of Operating Reactor Licensing; Steven Alferink, Reliability and Risk Analyst, Probability and Risk Assessment (PRA) Licensing Branch C; and Daniel Silverstein, Reliability and Risk Analyst, PRA Licensing Branch C in the Division of Risk Assessment.

4.0 AUDIT REPORT

During the audit period, the licensee used the Certrec portal to provide relevant information pertaining to the three topics listed in the Initial Audit Items List as well as licensees proposed responses for the three audit questions provided as part of the Audit Plan. NRC staff started reviewing this information from July 1, 2024. During the audit meeting on July 10, 2024, the licensee presented additional information not provided on Certrec and held further discussions with NRC staff regarding the proposed responses to the audit questions.

Based on these discussions, all the items in the list were marked as complete. NRC staff also found the proposed responses to Questions 2 and 3 satisfactory and stated that a docketed response was not needed. For Question 1, the need for additional information was identified, and NRC staff requested that this information be provided on docket to help reach its safety conclusion. Prior to the conclusion of the audit, the licensee decided to supplement its application to provide the information expected to be requested in a possible RAI. By letter dated July 26, 2024 (ML24208A169), the licensee supplemented its subm ittal to address Audit Question 1. The analytical basis for Audit Questions 2 and 3 were addressed sufficiently prior to the conclusion of the audit such that supplemental information would not need to be requested via an RAI(s).

5.0 CONCLUSION

As a result of the audit, the NRC staff gained a better understanding of Hatch plant-specific applicability and variations as compared to the LaSalle 10 CFR 50.69 precedent, the licensees experience and results using the seismic PRA in the approved 10 CFR 50.69 categorization process, and an understanding of any non-PRA-based qualitative assessments. As a result of the audit, the licensee supplemented its LAR by letter dated July 26, 2024 (ML24208A169).

ML24299A222 OFFICE NRR/DORL/LPLII-1/PM NRR/DORL/LPLII-1/LA NRR/DRA/APLC/BC(A)

NAME DKalathiveettil KGoldstein ANeuhausen DATE 10/24/2024 10/25/2024 10/28/2024 OFFICE NRR/DORL/LPLII-1/BC NRR/DORL/LPLII-1/PM NAME MMarkley DKalathiveettil DATE 10/31/2024 10/31/2024