ML25336A118
| ML25336A118 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/17/2025 |
| From: | Kimberly Green Plant Licensing Branch II |
| To: | Tennessee Valley Authority |
| Green K | |
| Shared Package | |
| ML25336A119 | List: |
| References | |
| EPID L-2025-LRM-0148 | |
| Download: ML25336A118 (0) | |
Text
December 17, 2025 LICENSEE:
Tennessee Valley Authority FACILITY:
Browns Ferry Nuclear Plant, Units 1, 2, and 3
SUBJECT:
SUMMARY
OF DECEMBER 1, 2025, PUBLIC TELECONFERENCE WITH TENNESSEE VALLEY AUTHORITY TO DISCUSS A PROPOSED LICENSE AMENDMENT REQUEST REGARDING ADDITION OF A SURVEILLANCE REQUIREMENT FOR THE INBOARD MAIN STEAM ISOLATION VALVES (EPID L-2025-LRM-0148)
On December 1, 2025, the U.S. Nuclear Regulatory Commission (NRC) held a public observation meeting via Microsoft Teams with representatives from the Tennessee Valley Authority (TVA) to discuss a forthcoming license amendment request (LAR) for the Browns Ferry Nuclear Plant, Units 1, 2, and 3 (BFN). The meeting notice and agenda for this meeting, dated November 20, 2025, are available at Agencywide Documents Access and Management System (ADAMS) Accession No. ML25325A044, and TVAs slides for the meeting are available at ADAMS Accession No. ML25329A045. A list of the meeting attendees is enclosed.
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Background===
2016 Design Change During the 2016 design change, TVA updated the design and licensing basis to credit a longer main steam isolation valve (MSIV) closure time. TVA performed an evaluation that showed the inboard MSIVs could close within 2 minutes after a loss-of-coolant accident (LOCA) using air and spring force.
Updated Final Safety Analysis Report (UFSAR), Amendment 26 In the UFSAR, TVA described a 10-second closure time using air or springs; however, the description did not properly account for increased drywell pressure after a design basis LOCA.
Evaluation Outcome Based on the evaluation, TVA determined that the increased closure time and method did not increase consequences of a LOCA, and that the credible failure mode (MSIV failing to close) was already considered and unaffected. TVA concluded that NRC approval was not required under Title 10 of the Code of Federal Regulations, Section 50.59.
2022 NRC Inspection Design Basis Assurance Inspection During the inspection, the NRC found a low safety significance issue with the 2016 evaluation and issued a Severity Level IV, non-cited violation.
Technical Specification (TS) Concerns The NRC inspectors noted that similar valves with gas pressure requirements had TS Surveillance Requirements (SRs) to verify pressure. TVA revised the UFSAR to show that inboard MSIVs now require both spring force and accumulator pressure to function under accident conditions.
Compliance and Corrective Actions:
TVA incorrectly determined that a TS change wasnt needed before implementing the design change. TVA entered the issue into the TVA Corrective Action Program. TVA took actions to add a new SR to the BFN TS to restore compliance.
TVAs Proposed LAR TVA plans to propose a revision to TS 3.6.1.3, Primary Containment Isolation Valves (PCIVs),
to add new SR 3.6.1.3.11. The new SR would verify a minimum control air pressure of 90 pounds per square inch gauge is supplied to the inboard MSIVs to ensure reliable closure under all design basis conditions. The proposed SR would be performed at a frequency in accordance with the Surveillance Frequency Control Program (SFCP). TVA noted that the proposed change is similar to the existing SR 3.5.1.3 for verification of minimum control air pressure supplied to the automatic depressurization system valves for reliable operation.
NRC Feedback The NRC staff requested that TVA include a brief summary in the LAR covering the design change that prompted the amendment and any corrective actions taken since the 2022 inspection. The staff suggested that information regarding why the outboard MSIVs would not be subject to the same SR would be helpful. Additionally, justification for the planned surveillance frequency should be included.
Schedule TVA plans to submit the LAR by December 31, 2025, and request NRC approval by July 2026.
No regulatory decisions were made at this meeting.
No comments or public meeting feedback forms were received.
Please direct any inquiries to me at 301-415-1627 or Kimberly.Green@nrc.gov.
/RA/
Kimberly J. Green, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296
Enclosure:
List of Attendees cc: Listserv
Enclosure LIST OF ATTENDEES DECEMBER 1, 2025, TELECONFERENCE WITH TENNESSEE VALLEY AUTHORITY PROPOSED LICENSE AMENDMENT REQUEST REGARING MSIVS BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 Name Organization Kim Green U.S. Nuclear Regulatory Commission (NRC)
David Nold NRC Josh Wilson NRC Milton Valentin NRC Khaing Wai NRC Beau Eckermann Tennessee Valley Authority (TVA)
Amber Aboulfaida TVA Gary Hicks TVA Edward Rink TVA
ML25336A119 (Package)
ML25329A045 (Slides)
ML25325A044 (Meeting Notice)
ML25336A118 (Meeting Summary)
NRC-001 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM NAME KGreen ABaxter DWrona KGreen DATE 12/01/2025 12/16/2025 12/17/2025 12/17/2025