Event Notification Report for April 12, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/11/2025 - 04/12/2025
EVENT NUMBERS
57663
57663
Power Reactor
Event Number: 57663
Facility: Columbia Generating Station
Region: 4 State: WA
Unit: [2] [] []
RX Type: [2] GE-5
NRC Notified By: Robert Rood
HQ OPS Officer: Ernest West
Region: 4 State: WA
Unit: [2] [] []
RX Type: [2] GE-5
NRC Notified By: Robert Rood
HQ OPS Officer: Ernest West
Notification Date: 04/12/2025
Notification Time: 08:17 [ET]
Event Date: 04/12/2025
Event Time: 02:23 [PDT]
Last Update Date: 04/12/2025
Notification Time: 08:17 [ET]
Event Date: 04/12/2025
Event Time: 02:23 [PDT]
Last Update Date: 04/12/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(i) - Plant S/D Reqd By TS 50.72(b)(3)(ii)(A) - Degraded Condition
10 CFR Section:
50.72(b)(2)(i) - Plant S/D Reqd By TS 50.72(b)(3)(ii)(A) - Degraded Condition
Person (Organization):
Vossmar, Patricia (R4DO)
Crouch, Howard (IR)
Mckenna, Phillip (NRR EO)
Vossmar, Patricia (R4DO)
Crouch, Howard (IR)
Mckenna, Phillip (NRR EO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Hot Shutdown | 0 | Hot Shutdown |
SHUTDOWN REQUIRED BY TECHNICAL SPECIFICATIONS
The following information was provided by the licensee via phone and email:
"During a planned shutdown at Columbia Generating Station for a refueling outage, pressure boundary leakage was identified from the bonnet vent line of loop `B' discharge motor operated isolation valve during a drywell inspection. Leakage was initially identified during a drywell entry at 15 percent [reactor] power and identified as pressure boundary leakage during a subsequent entry in mode 3. The leak exceeds technical specification (TS) 3.4.5 'RCS Operational Leakage' of no pressure boundary leakage. TS action `C' was entered, requiring [the plant to be in] mode 3 in 12 hours and mode 4 in 36 hours. Columbia Generating Station was in mode 3 at time of determination for [entering TS] 3.4.5. Therefore, the event is reportable within 4 hours per 10 CFR 50.72(b)(2)(i) due to the initiation of a plant shutdown required by the plant's TS.
"The event is also reportable within 8 hours per 10 CFR 50.72(b)(3)(ii)(A) due to an event that resulted in the condition of the nuclear power plant, including principal safety barriers, being seriously degraded."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The NRC Resident Inspector has been informed. Columbia Generating Station estimates the leak rate to be less than 0.2 gallons per minute. Columbia Generating Station expects to enter mode 4 within the required 36 hours.
The following information was provided by the licensee via phone and email:
"During a planned shutdown at Columbia Generating Station for a refueling outage, pressure boundary leakage was identified from the bonnet vent line of loop `B' discharge motor operated isolation valve during a drywell inspection. Leakage was initially identified during a drywell entry at 15 percent [reactor] power and identified as pressure boundary leakage during a subsequent entry in mode 3. The leak exceeds technical specification (TS) 3.4.5 'RCS Operational Leakage' of no pressure boundary leakage. TS action `C' was entered, requiring [the plant to be in] mode 3 in 12 hours and mode 4 in 36 hours. Columbia Generating Station was in mode 3 at time of determination for [entering TS] 3.4.5. Therefore, the event is reportable within 4 hours per 10 CFR 50.72(b)(2)(i) due to the initiation of a plant shutdown required by the plant's TS.
"The event is also reportable within 8 hours per 10 CFR 50.72(b)(3)(ii)(A) due to an event that resulted in the condition of the nuclear power plant, including principal safety barriers, being seriously degraded."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The NRC Resident Inspector has been informed. Columbia Generating Station estimates the leak rate to be less than 0.2 gallons per minute. Columbia Generating Station expects to enter mode 4 within the required 36 hours.