This report is being made per paragraphs 50.73(a)(1) and 50.73(a)(2)(iv)(A) to address an actuation of
Emergency Diesel Generator 'B' on May 8, 2014 during the performance of 480v safeguards Bus 16 Under Voltage (
UV) testing. Emergency
AC Electrical Power system, including
Emergency Diesel Generators, is a system named in 50.73(a)(2)(iv)(B).
During testing of the Bus 16 UV cabinet, a human performance error resulted in the simultaneous auto start of the 'B' Emergency Diesel Generator and trip of the Bus 16 normal supply breaker. This is defined as an 'invalid signal' in that the 'B' Emergency Diesel Generator did not start as the result of an actual UV condition on Bus 16.
This start signal is considered an INVALID signal with respect to 50.73(a)(2)(iv)(A), however the system was not fully removed from service. The 'A' train was not affected by this event. The actuation was considered complete since all necessary components responded as would have been expected if there had been a valid UV signal.
The NRC Resident lnspector was notified.
