Event Notification Report for January 27, 2024
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
01/26/2024 - 01/27/2024
EVENT NUMBERS
56935
56935
Power Reactor
Event Number: 56935
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: Bill Gott
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Ryan Nessell
HQ OPS Officer: Bill Gott
Notification Date: 01/27/2024
Notification Time: 23:39 [ET]
Event Date: 01/27/2024
Event Time: 21:41 [EST]
Last Update Date: 01/27/2024
Notification Time: 23:39 [ET]
Event Date: 01/27/2024
Event Time: 21:41 [EST]
Last Update Date: 01/27/2024
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):
Miller, Mark (R2DO)
Miller, Mark (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 email:
"At 2141 EDT, with Unit 2 in Mode 1 at 100 percent power, the reactor automatically tripped due to a main turbine trip. The trip was not complex, with all systems responding normally post-trip.
"Operations responded and stabilized the plant. Decay heat is being removed using the auxiliary feedwater and steam dump systems. 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 auxiliary feedwater 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 on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
"All control rods are fully inserted. The cause of the turbine trip is being investigated."
The licensee notified the NRC Resident Inspector.
The following information was provided by the licensee via email:
"At 2141 EDT, with Unit 2 in Mode 1 at 100 percent power, the reactor automatically tripped due to a main turbine trip. The trip was not complex, with all systems responding normally post-trip.
"Operations responded and stabilized the plant. Decay heat is being removed using the auxiliary feedwater and steam dump systems. 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 auxiliary feedwater 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 on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
"All control rods are fully inserted. The cause of the turbine trip is being investigated."
The licensee notified the NRC Resident Inspector.