Event Notification Report for July 13, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
07/12/2025 - 07/13/2025
EVENT NUMBERS
57810
57810
Power Reactor
Event Number: 57810
Facility: Watts Bar
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Ryan Nessell
HQ OPS Officer: Josue Ramirez
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Ryan Nessell
HQ OPS Officer: Josue Ramirez
Notification Date: 07/13/2025
Notification Time: 17:10 [ET]
Event Date: 07/13/2025
Event Time: 14:18 [EDT]
Last Update Date: 07/13/2025
Notification Time: 17:10 [ET]
Event Date: 07/13/2025
Event Time: 14:18 [EDT]
Last Update Date: 07/13/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Davis, Bradley (R2DO)
Davis, Bradley (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | A/R | Y | 100 | Power Operation | 0 | Hot Standby |
AUTOMATIC REACTOR TRIP
The following information was provided by the licensee via phone and email:
"At 1418 EDT on 7/13/2025, with Unit 2 in mode 1 at 100 percent power, the reactor automatically tripped due to a main turbine trip. The trip was not complicated with all systems responding normally post trip.
"Operators responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the steam dump system and the auxiliary feedwater (AFW) system. Unit 1 is not affected.
"Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72 (b)(2)(iv)(B). The expected actuation of the AFW system (an engineered safety feature) is being reported as an eight-hour report under 10 CFR 50.72 (b)(3)(iv)(A).
"There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The cause of the main turbine trip was due to the loss of both main feed pumps due to a loss of secondary power. The cause of the loss of secondary power is still being investigated.
The following information was provided by the licensee via phone and email:
"At 1418 EDT on 7/13/2025, with Unit 2 in mode 1 at 100 percent power, the reactor automatically tripped due to a main turbine trip. The trip was not complicated with all systems responding normally post trip.
"Operators responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the steam dump system and the auxiliary feedwater (AFW) system. Unit 1 is not affected.
"Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72 (b)(2)(iv)(B). The expected actuation of the AFW system (an engineered safety feature) is being reported as an eight-hour report under 10 CFR 50.72 (b)(3)(iv)(A).
"There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The cause of the main turbine trip was due to the loss of both main feed pumps due to a loss of secondary power. The cause of the loss of secondary power is still being investigated.