The following finding of very low significance was identified by the licensee and is a violation of NRC requirements, and, consistent with the
NRC Enforcement Policy, is being dispositioned as an
NCV.
10 CFR 50.63 Loss of All Alternating Current Power, requires in part that station batteries and other necessary support systems must provide sufficient capacity and capability to ensure the core is cooled and appropriate containment integrity is maintained in the event of a station blackout. Contrary to the above, on August 28, 2012 during
PM-452, Dedicated Shutdown
UPS Battery Test, the dedicated shutdown uninterruptible power supply (DS-UPS) batteries failed to meet the acceptance criteria. The licensee documented this condition in
NCR 557582 and
NCR 558425. The results of previous test indicated a negative trend in battery performance and that the battery should have been replaced before failure. The licensee initiated actions to replace the DS-UPS batteries. The inspectors evaluated this finding using NRC
Inspection Manual Chapter 0609 Appendix F, Fire Protection Significance Determination. The finding was screened as having very low safety significance (Green) because the assigned fire degradation rating was low. In addition, based upon licensee procedures and operator actions, it is reasonable to conclude that the dedicated shutdown diesel generator would have been started and available to provide power to the required
safe shutdown equipment prior to the battery falling below minimum voltage
