05000259/LER-2025-001-01, Reactor Scram Due to Low Reactor Water Level
| ML26029A088 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 01/29/2026 |
| From: | Komm D Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2025-001-01 | |
| Download: ML26029A088 (0) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 2592025001R01 - NRC Website | |
text
Post Office Box 2000, Decatur, Alabama 35609-2000 January 29, 2026 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 1 Renewed Facility Operating License No. DPR-33 NRC Docket No. 50-259
Subject:
Licensee Event Report 50-259/2025-001-01
Reference:
Letter from TVA to NRC, Licensee Event Report 50-259/2025-001-00, dated September 30, 2025 (ML25273A039)
The enclosed Licensee Event Report provides details of a SCRAM due to low reactor water level on Browns Ferry Nuclear Plant, Unit 1. 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. Revision 1 to this report includes information from the cause evaluation that 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, Site Regulatory Compliance Manager, at (256) 729-2636.
Respectfully, Daniel A. Komm Site Vice President Enclosure: Licensee Event Report 50-259/2025-001 Reactor SCRAM due to Low Reactor Water Level 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 1 Licensee Event Report 50-259/2025-001-01 Reactor SCRAM due to Low Reactor Water Level See Enclosed
Abstract
On August 1, 2025, at 2350 Central Daylight Time, Browns Ferry Unit 1 experienced an automatic scram due to low reactor water level. A low reactor water level of +2 inches resulted in a valid actuation of the Reactor Protection System which caused all of the rods to insert. During the scram response, there was a valid actuation of the Primary Containment Isolation System groups 2, 3, 6, & 8. Upon receipt of these signals, all components actuated as required. Following the scram, reactor water level lowered below the
- - 45 inch setpoint, actuating High Pressure Coolant Injection and Reactor Core Isolation Coolant and tripped both Reactor Recirculation pumps as required. Operations responded and stabilized the plant.
The root cause was determined to be the installed Foxboro Feedwater Level Control system design and subsequent reviews failed to identify the single point vulnerability and inherit potential failure modes for the Foxboro System. The root cause will be addressed through elimination of the single point vulnerability in the Reactor Feed Pump speed control system.
The Tennessee Valley Authority is submitting this report in accordance with Title 10 of the Code of Federal Regulations 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.
Page 6 of 6 B. Corrective Actions to Prevent Recurrence or to reduce the probability of similar events occurring in the future The Root Cause will be addressed through Corrective Action to Prevent Recurrence Action 2029788-002, which will eliminate the SPV in the Unit 1 Foxboro FWLCS. Additionally, Corrective Action 2029788-003 will update the Equipment Reliability classification for component BFN-1-XM-046-0097/52 based on the discovery of the SPV. Corrective Action 2029788-004 will verify that Foxboro system vulnerabilities are included in the distributed control system hazard review per CR 2029991.
VII. Previous Similar Events at the Same Site
There were no previous similar events at BFN within the last 5 years.
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].