ENS 58041

v t e ENS Event
03:54 Nov 15, 2025
Title	Automatic Actuation of Emergency AC Power System
Event Description	The following information was provided by the licensee via phone and email: At 2254 EST, on November 14, 2025, with Unit 2 in no mode at zero percent power, an actuation of the emergency AC power system occurred during verification of electrical system alignment. The reason for the Keowee Hydro units actuating was due to loss of power to the Unit 2 main feeder busses when a potential transformer drawer for the Unit 2 main feeder busses was opened, resulting in breakers supplying power to the Unit 2 main feeder busses opening. The Keowee Hydro Units 1 and 2 automatically started as designed when a main feeder bus undervoltage signal was received. There was no impact to Unit 1 or Unit 3. This event is being reported in accordance with 10CFR50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the emergency AC power system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

ENS 58041 +/-
Where
Oconee South Carolina (NRC Region 2)
Reporting

10 CFR 50.72(b)(3)(iv)(A), System Actuation
LER:	05000270/LER-2026-001 Loss of AC Power to Unit 2 Main Feeder Buses After Opening Potential Transformer Drawer Resulting in Actuation of Keowee Hydroelectric Units
Time - Person (Reporting Time:+1.63 h0.0679 days <br />0.0097 weeks <br />0.00223 months <br />)
Opened:	Paul Marshall 05:32 Nov 15, 2025
NRC Officer:	Kerby Scales
Last Updated:	Nov 15, 2025
58041 - NRC Website Loading map...
v • d • e

v t e Emergency Notification System
Oconee with 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2025-11-15T03:54:00 [Table view]
[ENS list for Oconee]

Navigation menu