ML25079A332
| ML25079A332 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 04/01/2025 |
| From: | John Lamb NRC/NRR/DORL/LPL2-1 |
| To: | Southern Nuclear Operating Co |
| Lamb J, NRR/DORL/LPL2-1 | |
| Shared Package | |
| ML25079A331 | List: |
| References | |
| EPID L-2025-LLA-0035 | |
| Download: ML25079A332 (7) | |
Text
April 1, 2025 LICENSEE:
Southern Nuclear Operating Company, Inc.
FACILITY:
Vogtle Electric Generating Plant, Units 3 and 4
SUBJECT:
SUMMARY
OF MARCH 18, 2025, FOLLOW-UP OBSERVATION MEETING HELD WITH SOUTHERN NUCLEAR OPERATING COMPANY, INC.,
REGARDING A LICENSE AMENDMENT REQUEST TO CHANGE TABLE 3.3.8-1 FOR VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 (EPID L-2025-LLA-0035)
On March 18, 2025, a follow-up Observation meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Southern Nuclear Operating Company, Inc. (SNC, the licensee). The purpose of the meeting was for SNC to describe its plan to submit a license amendment request (LAR) for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4.
On February 14, 2025 (Agencywide Documents and Access Management System (ADAMS)
Accession No. ML25045A166), SNC submitted a LAR to add to Technical Specification (TS)
Table 3.3.8-1 a new Tcold - High function for passive residual heat removal (PRHR) actuation logic at Vogtle, Units 3 and 4.
A pre-submittal meeting was held on October 15, 2024, and the meeting summary is located under ADAMS Accession No. ML24290A158. In addition, a public meeting was held on March 3, 2025, and the meeting summary is located under ADAMS Accession No. ML25063A190.
A list of attendees is provided as an Enclosure.
On March 6, 2025 (ML25065A006), the meeting was noticed on the NRC public web page.
The NRC staff opened the meeting with introductory remarks and a roll call of the attendees.
The SNC presentation materials are under ADAMS Accession Nos. ML25071A102, ML25071A103, and ML25073A103.
SNC representatives discussed the following topics: (1) introduction, (2) address additional details on safety analysis background, (3) address digital instrumentation and controls (DI&C) interim staff guidance (ISG)-06, Licensing Process, Revision 2, December 2018 (ML18269A259), for a software-only change, (4) schedule, and (5) discussion.
Safety Analysis SNC representative stated that, as stated in LAR Section 3, the safety analyses that credit PRHR actuation on Low-2 narrow range (NR) steam generator (SG) level coincident with Low-2 startup feedwater (SFW) flow are (1) Loss of Alternating Current (LOAC), and (2) Loss of Normal Feedwater (LONF) - both SGs affected, including LONF with consequential LOAC. The SNC representative said that, as stated in LAR Section 3, additional evaluation was performed for LONF - only one SG affected (Partial LONF).
SNC representatives stated that other non-limiting analyses not crediting PRHR actuation on Low-2 NR SG level remain unaffected by the proposed LAR. SNC stated that the planned supplement will provide a table of each limiting event in which PRHR actuation is credited and the credited actuation signal, along with applicable updated final safety analysis report (UFSAR) subsection. SNC further stated that an additional UFSAR subsection 6.3.3.4.1 mark-up will be included in the proposed supplement.
DI&C-ISG-06 DI&C-ISG-06 provides guidance for the NRC staffs review of LARs for the installation of DI&C equipment. SNC stated that the scope of the proposed LAR is a software-only change to Protection and Safety Monitoring System (PMS). SNC representatives said that the lack of hardware/architectural changes should provide for streamlined application of ISG-06 scope.
SNC stated that when based on an NRC-approved platform topical report, NRC staff should be able to limit its review to assessing whether the application of the DI&C modification conforms to the topical report approval. SNC stated that the following topical reports were approved:
WCAP-16097-P-A, Common Qualified Platform Topical Report (ML13112A110), and WCAP-16096-P-A, Software Program Manual for Common Q Systems (ML13081A047).
SNC representatives said that a safety determination before completion of detailed design, implementation, and testing should be allowed by the alternate review process in accordance with DI&C-ISG-06, Revision 2.
SNC representatives stated that the SNC Vendor Oversight Plan (VOP) is an umbrella document that describes SNC processes and procedures that establish governance for oversight of Westinghouse Electric Company (WEC) quality activities and product development during the project life cycle.
SNC representatives stated that the VOP summary that will be provided with the proposed LAR supplement will:
Describe processes and procedures to be used to review design artifacts and other technical products, Distinguish between SNC verification efforts and the verification and validation that WEC will conduct, as required by WCAP-16096-P-A, Software Program Manual for Common QTM Systems, and Identify the administrative control of, and change process for, the VOP, which will have provisions for maintaining and controlling the VOP to remain consistent with the NRC issued Amendment safety evaluation.
Schedule SNC stated that it would provide a LAR supplement based on the meeting. SNC said that the Westinghouse Electric Company (WEC) software development project schedule is proprietary/export controlled. SNC stated that it is requesting NRC issue the proposed LAR prior to the Vogtle, Unit 4, first refueling outage (RFO), which will occur in early fall 2025. SNC said that it plans to implement the proposed LAR during the Vogtle, Unit 3, second RFO, which will occur in spring 2026, and during the Vogtle, Unit 4, RFO, which will occur in early fall 2025.
Discussion The NRC staff asked the following questions:
Are any of the development and oversight activities completed?
When will the factory acceptance tests be completed?
Which revisions of the reports will be used?
What are the system design and requirements?
What is the detailed description of the software change?
Is there an AP1000-specific verification and validation (V&V) plan?
Is there a plant-specific test plan?
Public Questions There were three members of the public in attendance. Public members asked the following questions:
In the discussion of safety analysis impacts, it seems now there is the possibility of a new situation created by this proposal that did not exist before. There can be one SG removing heat, while the other SG is not removing heat, without causing actuation of the PRHR. There is a discussion of the adequacy of heat removal, and maybe some transients, due to having only one SG removing heat. Is there a discussion of the material and structural integrity concerns for this new situation (one SG removing heat; the other SG not removing much heat, a partial loss of normal function). The problem is that the situation is not symmetrical, and it is asymmetrical, and that asymmetry can cause thermal stresses and fatigue.
If SNC is pushing for an expedited approval, does that mean safety testing is being rushed? I am just a little worried as to my safety and my neighbors safety.
Closing Remarks The NRC staff did not make any regulatory decisions during the meeting. The NRC staff is in the process of thoroughly reviewing the LAR submitted by SNC on February 14, 2025. The NRC staff will make any regulatory decisions in writing in a timely manner. Public Meeting Feedback forms were available, but no comments were received.
The meeting adjourned at 3:16 pm eastern daylight savings time.
Please direct any inquiries to me at John.Lamb@nrc.gov or 301-415-3100.
/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:
List of Attendees cc: Listserv
Enclosure LIST OF ATTENDEES MARCH 18, 2025, PRE-SUBMITTAL MEETING WITH SOUTHERN NUCLEAR COMPANY REGARDING A PROPOSED LICENSE AMENDMENT REQUEST TO CHANGE TABLE 3.3.8-1 VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 ATTENDEE REPRESENTING John G. Lamb U.S. Nuclear Regulatory Commission (NRC)
Mike Markley NRC Zach Turner NRC Jo Ambrosini NRC Khadija West NRC Deanna Zhang NRC Angelo Stubbs NRC Norbert Carte NRC Kerri Kavanagh NRC Samir Darbali NRC Fanta Sacko NRC Jack Minzer Bryant NRC Ken Lowery Southern Nuclear Operating Company (SNC)
Ryan Joyce SNC Ray Herb SNC Joshua Olsen SNC Kimberly Yennerell SNC Dan Williamson SNC Eddie Grant SNC Robert Leighton SNC William Howell SNC Thomas Joseph Westinghouse Natalie Rogers Westinghouse Eric Resch Westinghouse Matthew Shakun Westinghouse Ali Alibeji Westinghouse Christopher Sommer Westinghouse Blaise Macioce Westinghouse Warren R. Odess-Gillett Westinghouse Thomas McLaughlin Westinghouse Ryan Rossman Westinghouse Warren Busch Sargent Lundy Pareez Golub Sargent Lundy Brian Arnholt Sargent Lundy ATTENDEE REPRESENTING Susan Sterrett Public Robert Armistead Public Michael James Public
PKG: ML25079A331 Meeting Notice: ML25065A006 Meeting Summary: ML25079A332 SNC Slides: ML25071A102, ML25071A103, and ML25073A103 NRC-001 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DEX/EICB/BC NAME JLamb KZeleznock FSacko DATE 03/20/2025 03/24/2025 03/31/2025 OFFICE NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME MMarkley JLamb DATE 04/01/2025 04/01/2025