The inspectors identified an
NCV of
10 CFR 50, Appendix B, Criterion XVI, Corrective Action, because Entergy did not promptly correct an adverse condition resulting in the failure of the B-UPS-1A
low pressure coolant injection (
LPCI) uninterruptible power supply (
UPS) battery. Specifically, Entergy personnel did not promptly replace a degraded battery cell prior to its exceeding operability limits. Entergys corrective actions included replacing cell 61, replacing all cells with individual cell voltages (
ICVs) less than 2.13 V, expediting complete battery bank replacements with a due date of May 30, and initiating a condition report. The finding is more than minor because it is associated with the Equipment Performance attribute of the
Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability and capability of systems that respond to
initiating events to prevent undesirable consequences (i.e. core damage). Specifically, UPS-1A had unplanned inoperability and degraded capacity due to cell 61 being out of service which commenced at some unknown point between December 3 and December 9 and was restored when cell 61 was replaced on December 10. In accordance with
IMC 0609.04, Initial Characterization of Findings, and
IMC 0609, Appendix A, The
Significance Determination Process for Findings At-Power, the inspectors determined that this finding is of very low safety significance (Green) because it did not represent a loss of system safety function or a loss of safety function for a single train (UPS-1A and A
LPCI) for greater than its technical specification allowed outage time (seven days). The inspectors determined that the finding had a crosscutting aspect in the Problem Identification and Resolution area, Operating Experience component, because Entergy personnel did not implement and institutionalize available operating experience guidance contained within
IEEE-450, IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications, or alternatively, vendor recommendations, to support plant safety.
