The team identified a non-cited violation of
10 CFR 50.63, Loss of all alternating current power, for failure to ensure
Regulatory Guide 1.155, Station Blackout commitments were implemented in calculations for restoring off-site power. The licensee entered this deficiency into their corrective action program for resolution. The licensees failure to maintain calculations to assure adequate voltage for the remote closing of
switchyard breakers during a station blackout event is a performance deficiency. The team determined that the finding is more than minor because it adversely affected the design control attribute of the mitigating reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. The finding is of very low safety significance (Green) using the
SDP because it did not represent a loss of system or safety function. A cross-cutting aspect was not identified because the finding does not represent current performance.
