ML25209A442
| ML25209A442 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 08/07/2025 |
| From: | John Lamb NRC/NRR/DORL/LPL2-1 |
| To: | Coleman J Southern Nuclear Operating Co |
| References | |
| EPID l-2025-LLA-0035 | |
| Download: ML25209A442 (1) | |
Text
August 7, 2025 Jamie M. Coleman Regulatory Affairs Director Southern Nuclear Operating Co., Inc.
3535 Colonnade Parkway Birmingham, AL 35243
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 - REGULATORY AUDIT
SUMMARY
IN SUPPORT OF THE REVIEW OF THE LICENSE AMENDMENT REQUEST TO ADD A NEW REACTOR COOLANT SYSTEM Tcold - HIGH FUNCTION TO ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION (EPID L-2025-LLA-0035)
Dear Ms. Coleman:
By letter dated February 14, 2025 (Agencywide Documents and Access Management System(ADAMS) Accession No. ML25045A166), as supplemented by letters dated March 31, July 9, and July 16, 2025 (ML25090A283, ML25190A653, and ML25197A672, respectively),
Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4. The proposed LAR would change the Technical Specifications 3.3.8, Engineered Safety Feature Actuation System (ESFAS) Instrumentation, Table 3.3.8-1, to add a new Function 11.b, Reactor Coolant System Cold Leg Temperature - High. SNC requested that the U. S. Nuclear Regulatory Commission (NRC) complete its safety review by August 29, 2025, to support planned implementation during the Vogtle, Unit 4, refueling outage. In June 2025, SNC informed the NRC staff that the proposed LAR would not be implemented prior to startup from the Fall 2025 refueling outage for Vogtle, Unit 4, and SNC requested the NRC staff to change the proposed implementation for Vogtle, Unit 4, to prior to the startup from the Spring 2027 refueling outage.
The NRC staff identified the need for a regulatory audit to examine SNCs non-docketed information with the intent of understanding, verifying information, or identifying information that will require docketing to support the basis of the licensing or regulatory decision.
By letter dated April 24, 2025 (ML25100A053), the NRC staff issued the audit plan. The audit plan was extended from July 15, 2025, to August 15, 2025, by letter dated July 1, 2025 (ML25177C976).
The NRC staff conducted a virtual audit via Microsoft Teams on May 27, June 24, July 16, July 21, and August 5, 2025.
The audit ended on August 7, 2025.
Attached is the audit Summary Report.
If you have any questions, please contact me at (301) 415-3100 or by email at John.Lamb@nrc.gov.
Sincerely,
/RA/
John G. Lamb, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos.52-025 and 52-026
Enclosure:
Audit Summary cc: Listserv
Enclosure REGULATORY AUDIT
SUMMARY
BY THE OFFICE OF NUCLEAR REACTOR REGULATION TO SUPPORT THE REVIEW OF THE LICENSE AMENDMENT REQUEST TO ADD A NEW TCOLD - HIGH FUNCTION SOUTHERN NUCLEAR OPERATING COMPANY VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 DOCKET NOS.52-025, AND 52-026
1.0 BACKGROUND
By letter dated February 14, 2025 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML25045A166), as supplemented by letters dated March 31, and July 9, and July 16, 2025 (ML25090A283, ML25190A653, and ML25197A672, respectively),
Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4. The proposed LAR would change the Technical Specifications (TS) 3.3.8, Engineered Safety Feature Actuation System (ESFAS) Instrumentation, Table 3.3.8-1, to add a new Function 11.b, Reactor Coolant System (RCS) Cold Leg Temperature (Tcold) - High. SNC requested that the U.S. Nuclear Regulatory Commission (NRC) complete its safety review by August 29, 2025, to support planned implementation during the Vogtle, Unit 4, refueling outage (RFO). In June 2025, SNC informed the NRC staff that the proposed LAR would not be implemented prior to starting up from the Fall 2025 RFO for Vogtle, Unit 4, and SNC asked the NRC staff to change the proposed implementation for Vogtle, Unit 4, prior to the startup from the Spring 2027 RFO.
The NRC staff identified the need for a regulatory audit to examine the SNCs non-docketed information with the intent to gain understanding, to verify information, or to identify information that will require docketing to support the basis of the licensing or regulatory decision.
By letter dated April 24, 2025 (ML25100A053), the NRC staff issued the audit plan. The audit plan was extended from July 15, 2025, to August 15, 2025, by letter dated July 1, 2025 (ML25177C976).
The NRC staff from the Office of Nuclear Reactor Regulation (NRR) initiated its review of the LAR in accordance with NRR Office Instruction LIC-101, License Amendment Review Procedures (ML19248C539).
2.0 REGULATORY AUDIT BASIS A regulatory audit is a planned license-or regulation-related activity that includes the examination and evaluation of primarily non-docketed information associated with the LAR. An audit is conducted to gain understanding, to verify information, and to identify information that will require docketing to support the basis of a licensing or regulatory decision. An audit will assist the NRC staff in efficiently conducting its review and gaining insights to the licensees processes and procedures. Information that the NRC staff relies upon to make the safety determination must be submitted on the docket. This audit will be conducted in accordance with NRR Office Instruction LIC-111, Regulatory Audits, Revision 1, dated October 2019 (ML19226A274), with exceptions noted within this audit plan.
The NRC staff performed the audit to support its evaluation of whether SNCs LAR can be approved per Title 10 of the Code of Federal Regulations (10 CFR), Section 50.90, Application for amendment of license, construction permit, or early site permit. The NRC staffs review was informed by NUREG-0800, Standard Review Plan. The audit assisted the NRC staff with understanding the licensees proposed LAR.
3.0 REGULATORY AUDIT
SUMMARY
AUDIT DAY 1 - MAY 27, 2025 On May 27, 2025, the NRC staff conducted a virtual audit via Microsoft Teams.
The attendees were:
John G. Lamb, NRC, Division of Operating Reactor Licensing (DORL)/Plant Licensing Branch 2-1 (LPL2-1)
Jo Ambrosini, NRC, Division of Safety Systems (DSS)/Nuclear Systems Performance Deanna Zhang, NRC, Division of Reactor Oversight (DRO)/Quality Assurance Vendor Inspection Branch (IQVB)
Zach Turner, DORL/LPL2-1 Mike Markley, NRC, DORL/LPL2-1 Norbert Carte, NRC, Division of Engineering and External Hazards (DEX)/Instrumentation and Controls Branch (EICB)
Nicholas Soliz, NRC, DSS/ Containment and Plant Systems (SCPB)
Ken Lowery, SNC James Chamberlain, SNC Ryan Joyce, SNC Dan Williamson, SNC Chris Sommer, SNC Ryan Rossman, SNC Warren Odess-Gillett, SNC Matt Shakun, SNC Eddie Grant, SNC The following audit questions were discussed.
Item #
Audit Questions/Discussions 1
Has the vendor oversight plan been developed and approved/issued?
2 Is NMP-ES-045-001 the procedure that governs owner acceptance of design output documents? If not, which procedure governs that process?
3 UFSAR Table 15.2-1 includes an annotation update indicating coincident with Tcold -
High for PRHR actuation, but the timing in the table remains unchanged. Is there AUDIT DAY 2 - JUNE 24, 2025 On June 24, 2025, the NRC staff conducted a virtual audit via Microsoft Teams.
The attendees were:
John G. Lamb, NRC, DORL/LPL2-1 Jamie Pelton, NRC, DORL Acting Director Deanna Zhang, NRC, DRO/IQVB Norbert Carte, NRC, DEX/EICB Ken Lowery, SNC William Howell, SNC Gregory Turk, SNC Joshua Olsen, SNC Brian Arnholt, Sargent & Lundy Chris Sommer, Westinghouse Electric Company (WEC)
Blaise Macioce, WEC Thomas McLaughlin, WEC The following audit questions were discussed.
Item #
Audit Questions/Discussions any change on the event sequence timing or does the PRHR heat exchanger still actuate at 637 seconds for accident II.A. Loss of ac power to the plant auxiliaries)?
This appears to be addressed in the LAR, which states: The results of the limiting case showed that the Tcold - High setpoint was reached 16.4 seconds after the Steam Generator (SG) narrow range water level signal was generated. Due to the existing proprietary preset time delay (which is significantly longer than 16.4 seconds) applied after the SG narrow range level is generated, the 16.4 second delay in reaching RCS Tcold signal has no impact on the most limiting case.
However, it is unclear whether this applies to all evaluated scenarios.
Item #
Audit Questions/Discussions 4
Can SNC verify that the following documents identified in the Vendor Oversight Plan (VOP) Summary and VOP are the only documents that will undergo owners acceptance review for this project?
- Software Hazards Analysis
- Failure Modes and Effects Analysis
- Requirements Traceability Matrix
- Software Test Plan 5
There are a couple of conditions identified in Section 8 of the VOP Summary that would trigger a condition report (CR) that do not make sense for the Passive Residual Heat Removal (PRHR) actuation logic change modification given that this modification is supposed to only affect software. This includes:
The following questions were also discussed:
Provide the VOP title and revision number in the VOP summary.
Section 6 of the VOP Summary states that SNC is crediting the software development process defined in NRC approved WCAP-16096, Software Program Manual for Common Q' Systems, as modified by WCAP-15927, Design Process for AP1000 Common QTM Safety under Westinghouses QA program. The NRC staff questioned if there is missing information in the above sentence. If so, the NRC staff requests that SNC revise the VOP Summary to accurately reflect the intent.
In addition, there was a discussion regarding the regulatory basis for NRC questions. The NRC noted that the regulatory basis for these questions includes Criterion III, Design Control, Criterion VII, Control of Purchased Material, Equipment, and Services, and Criterion XVI, Corrective Action of Appendix B, Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants, to 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities.
Item #
Audit Questions/Discussions Westinghouse noncompliance with the Westinghouse quality program, software processes, or hardware processes, Digital item quality is not assured, and identical or similar digital items are already installed in the facility, in other applications, and are considered operable or available.
Can SNC clarify why these conditions are written as to imply that there are hardware changes?
6 Questions regarding Plant Specific Action Items (PSAIs):
Section D.5 (see page E-19) in the table regarding ISG-06 Enclosure B Identified Alternate Review Process Applicable Sections in Enclosure NL-25-0072, Supplemental Information, states that The application of the NRC-approved Common Q Topical Reports (WCAP-16096 and WCAP-16097) to Protection and Safety Monitoring System (PMS), referenced in the VEGP [Vogtle Electric Generating Plant] 3&4 UFSAR [updated final safety analysis report], and the associated NRC Safety Evaluation Plant Specific Action Items were demonstrated satisfied during completion of ITAAC 2.5.02.12 [Index Number 551] as documented in NRC Integrated Inspection Reports 05200025/2019002, 05200026/2019002 [ML19220B678], are not affected by this LAR. SNC will provide oversight of the performance of the modification activities, in accordance with the VEGP 3&4 QA program and Vendor Oversight Plan per section C.2.2.
In addition, Section 6 of the VOP Summary identifies PSAI No. 23 (presume it is PSAI 6.23 in the Common Q topical report revision 3 SE) and PSAI No. 6 in the Common Q SPM, Revision 3. Both of these are records of change for each topical report.
There was a discussion that SNC requested to see the questions as draft with an opportunity for a clarifying call.
There was a discussion about a person from the NRC staff traveling to Westinghouse to witness testing in July 2025.
AUDIT DAY 3 - JULY 16, 2025 On July 16, 2025, the NRC staff conducted a virtual audit via Microsoft Teams.
The attendees were:
John G. Lamb, NRC, DORL/LPL2-1 Zach Turner, NRC, DORL/LPL2-1 Deanna Zhang, NRC, DRO/IQVB Ken Lowery, SNC Joshua Olsen, SNC Kimberly Yennerell, SNC William Howell, SNC Dan Williamson, SNC Brian Arnholt, Sargent & Lundy By letter dated July 9, 2025 (ML25190A653), SNC responded to the NRC Request for Additional Information (RAI) dated June 25, 2025 (ML25176A177).
SNC Response to RAI #3 states:
The attached VOP Summary provides the requested change to clarify that SNC will owner accept delivered WEC documents, which are not strictly limited to those documents listed in the RAI. Refer to Design Artifacts subsection.
SNC Response to RAI #4 states:
The attached VOP Summary provides the requested change, which removes discussions implying hardware changes may be associated with the requested Amendment.
The NRC discussed the following:
For the RAI #3 response, where exactly is the change (page number) in the revised Vendor Oversight Plan (VOP) Summary that documents the response to this RAI.
For the RAI #4 response, the last four bullets of Section 8 of the VOP Summary and corresponding VOP, Revision 2, still do not make sense for conditions that will trigger the initiation of a Condition Report (CR). Can SNC please verify that there are no words missing prior to the last four bullets?
SNC said that it would provide a supplement. By letter dated July 16, 2025, SNC provided a supplement.
AUDIT DAY 4 - JULY 21, 2025 On July 21, 2025, the NRC staff conducted an onsite audit at the Westinghouse Electric Corporation (WEC) facility in Pennsylvania.
The attendees were:
Norbert Carte, NRC, DEX/EICB Chris Sommer, WEC, Licensing Kim Yennerell, SNC, Digital I&C Ken Lowery, SNC, Licensing (virtual)
Kaite Swab, WEC, Project Manager Lena DeLucia, WEC, PMS Software Jeff Mascitelli, WEC, PMS Software Patrick Williams, WEC, IV&V Murat Uzman, WEC, IV&V Dom Mocello, WEC, PMS Test Jeff Rosser, WEC, PMS Test The NRC staff traced a sample of requirements from design through to testing at WEC. For the technical details that were traced, randomly selected by NRC Staff, the project WEC staff were able to show both forward and backwards traceability, as requested. Testing had not yet started, but tracing includes test procedures.
Documents Viewed:
APP-FSAR-GEF-506, Rev. 0, Logic Updates for PRHR HX Actuation and SFW Control (PINs 2458 and 2488) and Implementation of Dual Safety-Related Solenoids (PIN 2805)
WNA-RL-07457-WAPP, Rev. 0, AP1000 Haiyang Lessons Learned and Single Point Vulnerability Interim Release Lette for PMS Functional and System Design WNA-RL-07894-SV0, Rev 0, Vogtle Units 3&4 - AP1000 Haiyang Lessons Learned and Single Point Vulnerability Interim Release Letter for PMS Functional and System Design LTR-GIC-SSE-25-011, Rev. 0, Vogtle Units 3&4 AP1000 Haiyang Lessons Learned and Single Point Vulnerability - Preliminary Protection & Safety Monitoring System (PMS) Software Markups LTR-GIC-SSE-21-022, Rev. 4, Supplemental Release Information for Vogtle AP1000 PMS Software (Release 9.0.0.5)
APP-PMS-J4-102, Rev. 22, AP1000 Protection and Safety Monitoring System Software Requirements Specification WNA-RL-06470-WAPP, Rev. 1, AC160 Software Release Record for LCL-ESF Draft of SV0-PMS-T1D-039, Rev. 0, Design Optimization in Response to Safeguards Actuation Events for Vogtle Units 3 & 4 Miscellaneous I/O Logic Interface Test Data Sheets AUDIT DAY 5 - AUGUST 5, 2025 On August 5, 2025, the NRC staff conducted a virtual audit via Microsoft Teams.
The attendees were:
John G. Lamb, NRC, DORL/LPL2-1 Zach Turner, NRC, DORL/LPL 2-1 Ken Lowery, SNC The audit outcome was discussed.
4.0 REGULATORY AUDIT OUTCOME Question 1 was modified based on the audit discussions and was asked as a formal request for additional information (RAI) dated June 25, 2025 (ML25176A177).
Question 2 was modified based on the audit discussions and was asked as a formal RAI dated June 25, 2025 (ML25176A177).
Question 3 was resolved as part of the audit. There is no follow-up needed.
Question 4 was renumbered to Question 3 and asked as a formal RAI dated June 25, 2025 (ML25176A177).
Question 5 was renumbered to Question 4 and asked as a formal RAI dated June 25, 2025 (ML25176A177).
Question 6 was renumbered to Question 5 and asked as a formal RAI dated June 25, 2025 (ML25176A177).
SNC responded to the RAIs by letters dated July 9 and July 16, 2025 (ML25190A653 and ML25197A672, respectively).
5.0 CONCLUSION
The audit was closed out on August 7, 2025.
- via eConcurrence NRR-106 OFFICE NRR/DORL/LPLII-1/PM NRR/DORL/LPLII-1/LA NRR/DSS/SNSB/BC NRR/DEX/EICB/BC NAME JLamb KZeleznock (KEntz for)
NDifrancesco (SSun for) FSacko (NCarte for)
DATE 7/29/2025 7/30/2025 8/5/2025 8/5/2025 OFFICE NRR/DRO/IQVB/BC NRR/DORL/LPLII-1/BC NRR/DORL/LPLII-1/PM NAME KKavanagh (DZhang for) MMarkley JLamb DATE 8/5/2025 8/7/2025 8/7/2025