This telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report an invalid Engineered Safeguards Feature (
ESF) actuation of the
Auxiliary Feedwater(
AFW) system reportable under 10 CFR 50.73(a)(2)(iv)(A).
On April 16, 2007, at 2223 with Unit 1 in Mode 3, starting up from refueling outage 18, the 11 Steam Generator Feed Pump (SGFP) trip AFW Pump Auto Armed light extinguished unexpectedly and the Steam Generator (SG) sample valves 11 through 14-SS94 and SG Blowdown valves 11 through 14-GB4 closed. At the time, the 11 and 12 SGFPs were already tripped and the 11 and 12 Auxiliary Feedwater pumps were in service. No control room manipulations were in progress. A signal was generated to start the already in service AFW pumps.
The invalid signal to start the AFW pumps was determined to be from a faulty SGFP alternate trip relay. The defective relay was replaced and the isolation signal was reset and retested satisfactorily.
This event is reportable under 10 CFR 50.73(a)(2)(iv)(A) as an invalid ESF actuation and invalid system actuation.
The licensee notified the NRC Resident Inspector.