Event Notification Report for January 27, 2022
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
01/26/2022 - 01/27/2022
Power Reactor
Event Number: 55713
Facility: Oconee
Region: 2 State: SC
Unit: [3] [] []
RX Type: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-LP
NRC Notified By: Gabe Slaughter
HQ OPS Officer: Karen Cotton-Gross
Notification Date: 01/26/2022
Notification Time: 18:49 [ET]
Event Date: 01/26/2022
Event Time: 10:50 [EST]
Last Update Date: 01/26/2022
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(A) - Pot Unable To Safe Sd
Person (Organization):
Miller, Mark (R2)
Power Reactor Unit Info
| Unit |
SCRAM Code |
RX Crit |
Initial PWR |
Initial RX Mode |
Current PWR |
Current RX Mode |
| 3 |
N |
Y |
100 |
Power Operation |
100 |
Power Operation |
Event Text
REQUIRED OFFSITE AND BOTH ONSITE EMERGENCY AC POWER PATHS INOPERABLE
Licensee provided the following information via email:
"At 1050 EST on January 26, 2022, it was discovered that the required offsite and the overhead and underground paths of onsite emergency AC power were simultaneously inoperable; therefore this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(A).
"The overhead path and both required offsite paths were inoperable due to a lockout of the Unit 3 Startup Transformer CT-3. The underground path was made momentarily inoperable as part of aligning an additional offsite power source to Unit 3 to provide defense in depth to a loss of power.
"The safety function was restored at 1051 EST when the underground path was declared OPERABLE. The offsite power source was restored at 1651 EST. There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified."
* * * UPDATE ON 1/26/22 AT 2237 EST FROM GABE SLAUGHTER TO KAREN COTTON * * *
The Licensee updated the 3rd paragraph above as follows via email:
"The safety function was restored at 1051 EST when the underground path was declared OPERABLE. An offsite power source was restored through Transformer CT-5 within 15 minutes. Startup transformer CT-3 was restored and all offsite and the onsite overhead power source were returned to service by 1651 EST. Investigation of the cause of the CT-3 lockout is in progress. There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified of this update."