On 05/03/2011 at 0514 [EDT] V.C. Summer Nuclear Station (
VCSNS) determined the following:
During circuit analysis review for transitioning the Fire Protection Program to NFPA-0805, VCSNS identified two violations of the Appendix R requirement to maintain one train of systems necessary to achieve and maintain hot shutdown conditions in accordance with Appendix R. Both instances apply to postulated fires in the Main Control Room and Cable Spreading Room.
In the first instance, circuits were identified in the Main Control Room and Cable Spreading Room that impact a control power circuit that could result in the loss of ability to start the 'B' Emergency Diesel Generator using local controls. Because fires in these areas can result in the need to evacuate the Main Control Room, the inability to start the diesel using local controls could have an adverse impact on the ability to safely shut down the plant.
In the second instance, VCSNS determined that a fire in either the Main Control Room or Cable Spreading Room could result in a hot short that could actuate a relay and trip all incoming breakers to the B-train essential electrical bus (Bus 1DB). Because fires in these areas can result in a loss of power to the bus, this could have an adverse impact on the ability to safely shut down the plant.
The NRC Resident Inspector has been informed.