Event Notification Report for March 07, 2011

INVALID ACTUATION OF THE AUXILIARY FEEDWATER SYSTEM

"On March 7, 2011 at 1118 hours with Beaver Valley Power Station Unit 2 in Mode 5 during a scheduled refueling outage an invalid actuation of the Auxiliary Feedwater (AFW) System occurred. Instrumentation & Control (I&C) technicians were using a procedure to place simulated signals in two out of three channels of the narrow range level indication on all three steam generators (SG). During this activity, I&C technicians repositioned the input test relays to the test position on both channel 1 and channel 2 in two out of three SGs before inserting the simulated signals. This action resulted in a zero level input to the SG level circuits in two out of three SGs. An Engineered Safety Feature Actuation System (ESFAS) actuation signal for the Auxiliary Feedwater (AFW) System was generated based on having a two out of three low-low level signal in at least one SG (starts turbine driven AFW pump) and subsequently having a two out of three steam generators low-low level signal in at least two SGs (starts motor driven AFW pumps). The AFW initiation signal resulted in a successful automatic start of both the Train A and Train B motor driven AFW pumps. The AFW pump discharge flow control valves were closed per procedure prior to this event, so the motor driven AFW pumps operated on 100% recirculation flow following their automatic start. The turbine driven AFW pump did not start since steam pressure was not present in the main steam lines due to the plant being in Mode 5. A Reactor Protection Signal (RPS) signal was also generated due to having a two out of three low-low level signal in at least one SG. The RPS actuation signal did not result in opening of the reactor trip breakers since the breakers were previously opened as part of the plant shutdown procedures. The reactor control rods had been fully inserted into the reactor core prior to this event. Plant operators took appropriate actions to secure AFW flow after determining that the actuation was invalid and the issue was entered into the corrective action program for evaluation.

"The initiation of an ESFAS and RPS actuation signal, due to a SG low-low level signal, was not in response to any valid system or plant condition. There was no event, transient or condition that required any type of mitigation in Mode 5. Plant equipment responded as expected based on the conditions prior to the event.

'The invalid actuation of the AFW system is reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) since it involved an actuation of a PWR auxiliary feedwater system train per 10 CFR 50.73(a)(2)(iv)(B)(6). Per 10 CFR 50.73(a)(2)(iv)(A)(2)(ii), the actuation of the RPS due to a SG low-low signal is not reportable since the actuation was invalid and occurred after the safety function had already been completed (i.e. the RPS actuation occurred after the control rods had already been inserted in the core).

"Pursuant to 10 CFR 50.73(a)(1), this event is being reported via this telephone notification, in lieu of a written Licensee Event Report, since the automatic actuation of both trains of AFW was invalid."

The licensee has notified the NRC Resident Inspector.

INADVERTANT AUTO-START SIGNAL TO THE 1B DIESEL GENERATOR DURING TESTING

"Farley Unit One was conducting FNP-1-STP-80.8, [test procedure for] 1B DG [Diesel Generator] 1000 KW load rejection. After successfully completing the load rejection portion of the procedure, the control room staff was restoring the 1B diesel to a normal auto start alignment. With the 1B diesel running, the plant operator was required to reset the 1B DG loading sequencer. He incorrectly pressed the Emergency Start reset push-button instead of the Sequencer reset push-button. As a result, the Emergency Diesel generator stop light illuminated for a brief few seconds and then extinguished. Subsequently due to the test configuration, the 1B diesel received an auto-start signal and returned to the running condition prior to the Emergency Start reset. Although further investigation is continuing, this report is being made due to an apparent valid actuation of ESF equipment."

This event had no impact on other equipment or the plant electrical alignment. The Sequencer reset push-button and the Emergency Start reset push-button are not in close proximity to each other. The plant operator was assessed for fatigue and it was determined that fatigue was not a factor. The plant operator was removed from duties pending remedial training and assessment.

The licensee has notified the NRC Resident Inspector.

* * * RETRACTION FROM STEVE GATES TO JOE O'HARA AT 1342 ON 03/09/11 * * *

"The 8-hour non-emergency report (EN #46661) per 10CFR50.72(b)(3)(iv)(A) was conservatively reported based on the potential for a valid actuation of an Emergency Diesel Generator (EDG) during a 1000 KW load rejection surveillance test.

"During the restoration phase of the load rejection test to align the 1B EDG to a normal shutdown configuration, a plant operator incorrectly pressed the Emergency Start Reset (ESR) push-button instead of the Sequencer Reset push-button. As a result, the 1B EDG stop light illuminated momentarily and then extinguished. The 1B EDG received a momentary shutdown signal, but remained in a running condition.

"Upon completion of the 1B EDG circuit analysis, It was determined that the 1B EDG did not receive a valid actuation of the EDG safety function. Depressing the ESR push-button caused the emergency start relays to deenergize and remain de-energized. The emergency start relays energize on receipt of valid signals in response to actual plant conditions or parameters satisfying the requirements for the initiation of the safety function of the EDG. Therefore per section 3.2.6 of NUREG-1022, the 1B EDG did not receive a valid actuation signal."

The NRC Resident Inspector has been notified.

Notified R2DO(Musser)