ML24235A497
| ML24235A497 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/22/2024 |
| From: | Komm D Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| Download: ML24235A497 (1) | |
Text
Post Office Box 2000, Decatur, Alabama 35609-2000
August 22, 2024
ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001
Browns Ferry Nuclear Plant, Unit 3 Renewed Facility Operating License No. DPR-68 NRC Docket No. 50-296
Subject:
Updated Report of a Deviation or Failure to Comply Associated with a Valve in the Unit 3 High Pressure Coolant Injection System
Reference:
Interim Report of a Deviation or Failure to Comply Associated with a Valve in the Unit 3 High Pressure Coolant Injection System, dated June 23, 2024 (ML24175A004)
In accordance with the requirements of Title 10 of the Code of Federal Regulations (10 CFR) 21.21(a)(2), the Tennessee Valley Authority is submitting a follow-up report to the interim notification listed in the reference.
On March 3, 2024, excessive valve stem rotation was observed while troubleshooting the BFN, Unit 3, High Pressure Coolant Injection (HPCI) outboard steam isolation valve. This issue was promptly entered into the BFN Corrective Action Program (CAP) as Condition Report (CR) 1914295.
On April 24, 2024, TVA completed its 10 CFR Part 21 discovery process and determined the need to perform a 10 CFR Part 21 Evaluation. This Part 21 Evaluation is being tracked by TVA under CR 1926691. The vendor, Flowserve, was contacted and has assumed responsibility for performing the Part 21 Evaluation for this valve. However, the vendors evaluation is ongoing. Flowserve is tracking this failure event as non-conformance report (NCR) 202408-106129.
An independent failure analysis by MPR Associates, Inc. has been provided to Flowserve to help them with their evaluation. This report concluded that the event was apparently caused by an improper upper wedge-to-stem joint, and this this mismatch in mating surface diameter resulted in bending stress which led to the valve failure.
U.S. Nuclear Regulatory Commission Page 2 August 22, 2024
There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact David Renn, Site Licensing Manager, at (256) 729-2636.
Respectfully,
Daniel A. Komm Site Vice President
cc:
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant