05000260/LER-2025-001, Reactor Scram Due to Low Electro-Hydraulic Control Pressure
| ML25191A210 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/10/2025 |
| From: | Komm D Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2025-001-00 | |
| Download: ML25191A210 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 2602025001R00 - NRC Website | |
text
Post Office Box 2000, Decatur, Alabama 35609-2000 July 10, 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 50-260/2025-001 Reactor SCRAM due to Low Electro-Hydraulic Control Pressure The enclosed Licensee Event Report provides details of a SCRAM due to low electro-hydraulic control pressure on Browns Ferry Nuclear Plant, Unit 2, followed by a second automatic Reactor Protection System actuation due to a low reactor water level transient caused by manually opening and closing a main steam relief valve. 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)(iv)(A), as any event or condition that resulted in a manual or automatic actuation of the Reactor Protection System and Primary Containment Isolation System. A supplement to this Licensee Event Report is planned to allow additional time to complete the cause evaluation.
There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact David J. Renn, Site Compliance Manager, at (256) 729-2636.
Respectfully, Daniel A. Komm Site Vice President Enclosure: Licensee Event Report 50-260/2025-001 Reactor SCRAM due to Low Electro-Hydraulic Control Pressure 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 50-260/2025-001-00 Reactor SCRAM due to Low Electro-Hydraulic Control Pressure See Enclosed
Abstract
On May 12, 2025, at 1353 Central Standard Time (CST), Browns Ferry Nuclear Plant, Unit 2, experienced a significant electro-hydraulic control (EHC) leak, resulting in a turbine trip and automatic reactor SCRAM on low EHC pressure. The trip was not complex with all systems responding normally post trip except for the turbine bypass valves, which subsequently failed closed due to loss of EHC pressure. At 1407 CST, with Unit 2 in Mode 3, there was a second automatic RPS actuation due to a low reactor water level transient caused by manually opening and closing a main steam relief valve. Event Notification 57705 was made to the NRC Operations Center on May 12, 2025, at 1731 CST.
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)(iv)(A), as any event or condition that resulted in manual or automatic actuation of the Reactor Protection System and the Primary Containment Isolation System.
There will be a supplement to this Licensee Event Report once the cause evaluation is completed.
A. Immediate Corrective Actions
Shutoff valve and mounting bolts were replaced.
B. Corrective Actions to Prevent Recurrence or to reduce the probability of similar events occurring in the future There will be a supplement to this Licensee Event Report once the cause evaluation is completed.
VII. Previous Similar Events at the Same Site
There were no previous similar events found at the site.
VIII. Additional Information
There is no additional information.
IX.
Commitments
There are no new commitments.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].