05000259/LER-2024-001-02, Secondary Containment Isolation Valve Inoperable Due to Mechanical Failure

Secondary Containment Isolation Valve Inoperable Due to Mechanical Failure

ML24302A223
Person / Time
Site:	Browns Ferry
Issue date:	10/28/2024
From:	Komm D Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
LER 2024-001-02
Download: ML24302A223 (1)

LER-2024-001, Secondary Containment Isolation Valve Inoperable Due to Mechanical Failure

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
2592024001R02 - NRC Website

text

Post Office Box 2000, Decatur, Alabama 35609-2000 October 28, 2024 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, -52, and -68 NRC Docket Nos. 50-259, -260, and -296 Subject:

Licensee Event Report 50-260/2024-001-02 References:

1. Letter from TVA to NRC, Licensee Event Report 50-260/2024-001-00, dated February 16, 2024 (ML24047A222)

2. Letter from TVA to NRC, Licensee Event Report 50-260/2024-001-01, dated April 17, 2024 (ML24108A183)

The enclosed Licensee Event Report provides details of a failed Secondary Containment Isolation Valve on Browns Ferry Nuclear Plant, Units 1, 2, and 3. The Tennessee Valley Authority is submitting this report in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.73(a)(2)(i)(B), as any operation or condition which was prohibited by the plants Technical Specifications. Revision 2 to this report includes applicability to BFN Units 1 and 3 which was not previously reported.

There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact David J. Renn, Nuclear Site Licensing Manager, at (256) 729-2636.

Respectfully, Daniel A. Komm Site Vice President Enclosure: Licensee Event Report 50-260/2024-001 Secondary Containment Isolation Valve Inoperable due to Mechanical Failure

U.S. Nuclear Regulatory Commission Page 2 October 28, 2024 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 Units 1, 2, and 3 Licensee Event Report 50-260/2024-001-02 Secondary Containment Isolation Valve Inoperable due to Mechanical Failure See Enclosed

Abstract

On November 18, 2023, at approximately 2038 Central Standard Time, during performance of Surveillance Requirement 3.6.4.2.1, Secondary Containment Isolation Valve (SCIV) Stroke Timing, Reactor Zone Outboard Supply Damper 2-DMP-0064-0013 failed to close upon securing Reactor Zone Supply Fans. Operations personnel declared 2-DMP-064-0013 inoperable for SCIV function and entered Technical Specification Limiting Condition for Operation 3.6.4.2 Condition A. On November 22, 2023, 1515 CST, following corrective maintenance on the damper, Operations personnel declared damper 2-DMP-064-0013 operable for SCIV function and exited TS LCO 3.6.4.2 Condition A. On December 18, 2023, a Past Operability Evaluation determined that the damper had been inoperable for longer than allowed by TS. This condition did not result in any loss of safety function.

The apparent cause of this event was a lack of proper guidance in damper maintenance instructions. The corrective actions to reduce the possibility of recurrence for this condition are to replace broken and/or degraded components on the affected valve, and to revise maintenance procedures for the dampers to include an updated Preventative Maintenance plan with Electric Power Research Institute maintenance guidance.

Revision 2 to this report includes applicability to BFN Units 1 and 3 which was not previously reported.

Page 7 of 7 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 no similar events.

VIII. Additional Information There is no additional information.

IX.

Commitments There are no new commitments.