05000260/LER-2023-002, Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints
| ML23216A176 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/04/2023 |
| From: | Sivaraman M Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2023-002-00 | |
| Download: ML23216A176 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2602023002R00 - NRC Website | |
text
Post Office Box 2000, Decatur, Alabama 35609-2000 August 4, 2023 10 CFR 50.73 10 CFR 50.4(a)
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 50-260/2023-002 Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints The enclosed Licensee Event Report provides 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 Michael W. Oliver, Acting Site Licensing Manager, at (256) 729-2636.
Respectfully, Manu Sivaraman Site Vice President Enclosure: Licensee Event Report 50-260/2023-002 Main Steam Relief Valves Lift Settings Outside of Technical Specifications Required Setpoints 1\\14 TENNESSEE VALLEY AUTHORITY
U.S. Nuclear Regulatory Commission Page 2 August 4, 2023
cc (w/ Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant
Abstract
On June 5, 2023, the Tennessee Valley Authority was notified of as-found testing results that four (4) 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 were still able to perform their safety function.
It was determined that one MSRV failed due to corrosion bonding to the valve seats and non-quantifiable leakage known as simmering. Three MSRVs failed below their setpoints due to relaxed setpoint springs. All thirteen of the MSRV pilot valves were replaced during the Unit 2 Spring 2023 refueling outage. The Boiling Water Reactor Owners' Group is continuing to work toward a solution to improve the quality and adhesion of the platinum coating on the discs. BFN will take additional actions to verify that the springs associated with each low failure passes Spring Rate testing or is replaced.
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Commitments
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