On July 20, 2021, at 1707 EDT, an apparent non-compliance with
10 CFR 50, Appendix R, section III.G.2 (separation of redundant fire
safe shutdown equipment) was identified. This issue was initially categorized as not affecting train separation or the ability of the equipment to perform their Design Basis functions. The original concern was entered into the licensee's Corrective Action Program as CR1177199.
Subsequently, on July 22, 2021, at 1751 EDT, a further review of the affected control circuits for the Unit 1 and Unit 2 Emergency Diesel Generator (EDG) output breakers and emergency bus feeder breakers identified a concern that breaker position interlocks routed to or through non-safety related components or spaces may affect the ability to provide emergency power on the affected unit due to impacts on the control power circuits during an Appendix R fire associated with a loss of offsite power.
The following are the affected fire areas:
- Unit 1 and Unit 2 Turbine Buildings
- Unit 1 and Unit 2 Cable Spreading Rooms
- Unit 1 and Unit 2 Normal (307) Switchgear Rooms
This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B). This is also reportable as a 60-day written report pursuant to 10 CFR 50.73(a)(2)(ii)(B). This event was entered into the licensee's Corrective Action Program as CR 1177399.
The NRC Resident Inspector has been notified of this event.
