05000260/LER-2025-004, Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints
| ML25237A236 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  (DPR-052) |
| Issue date: | 08/25/2025 |
| From: | Komm D Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2025-004-00 | |
| Download: ML25237A236 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2602025004R00 - NRC Website | |
text
Post Office Box 2000, Decatur, Alabama 35609-2000 August 25, 2025 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 2 Renewed Facility Operating License No. DPR-52 NRC Docket No. 50-260
Subject:
Licensee Event Report 50-260/2025-004 Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints The enclosed Licensee Event Report provides the details of Main Steam Relief Valves which failed to meet their Surveillance Requirements for longer than allowed by plant Technical Specifications. The Tennessee Valley Authority is submitting this report in accordance with Title 10 of the Code of Federal Regulations 50.73(a)(2)(i)(B), as any operation or condition which was prohibited by the plants Technical Specifications.
There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact David J. Renn, Site Regulatory Compliance Manager, at (256) 729-2636.
Respectfully, Daniel A. Komm Site Vice President Enclosure: Licensee Event Report 50-260/2025-004 Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints cc (w/ Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant
ENCLOSURE Browns Ferry Nuclear Plant Unit 2 Licensee Event Report 50-260/2025-004-00 Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints See Enclosed
Abstract
On June 25, 2025, the Tennessee Valley Authority (TVA) was notified of as-found test results that four Main Steam Relief Valves (MSRVs) from Browns Ferry Nuclear Pant (BFN), Unit 2, were outside of their Surveillance Requirement limits for an indeterminate amount of time. These affected valves remained capable of maintaining reactor pressure within the American Society of Mechanical Engineers code limits and could perform their safety function.
It was determined that four MSRVs failed above their setpoints due to corrosion bonding to the valve seats. One of these four had been declared inoperable during the fuel cycle due to simmering and gross leakage. All thirteen of the MSRV pilot valves were replaced during the Unit 2 Spring 2025 refueling outage (2R23).
A. Immediate Corrective Actions
All thirteen of the BFN, Unit 2 MSRV pilot valves were replaced with refurbished valves during 2R23. As left testing verified that these refurbished pilot valves were within +/- 1 percent of their setpoints.
B. Corrective Actions to Prevent Recurrence or to reduce the probability of similar events occurring in the future As discussed in previous, similar BFN LERs, a flaking issue has been noted with the platinum coated pilot discs. The Boiling Water Reactor Owners' Group (BWROG) is continuing to work toward a solution to improve the quality and adhesion of the platinum coating on the discs. The corrective actions suggested by the BWROG will be incorporated to correct setpoint drift. To reduce the probability of seat leakage occurring in the future, pilot seat rebuilds will be performed in valves that have low stellite in the seat.
VII. Previous Similar Events at the Same Site
A search of LERs from BFN, Units 1, 2, and 3 over the last five years identified eight LERs associated with MSRV lift settings outside of TS required setpoints:
LER 50-259/2024-004-00, for Unit 1 Cycle 15 LER 50-296/2024-003-00, for Unit 3 Cycle 21 LER 50-260/2023-002-00, for Unit 2 Cycle 22 LER 50-259/2022-003-00, for Unit 1 Cycle 14 LER 50-296/2022-001-00, for Unit 3 Cycle 20 LER 50-260/2021-002-00, for Unit 2 Cycle 21 LER 50-259/2020-003-01, for Unit 1 Cycle 13 LER 50-296/2020-002-00, for Unit 3 Cycle 19
VIII. Additional Information
There is no additional information.
IX.
Commitments
There are no new commitments.