Event Notification Report for February 11, 2005

NOTIFICATION TO NEW YORK STATE PSC INVOLVING RADWASTE SHIPMENT INCIDENT OFFSITE

"Notified by Barnwell Waste Management Facility that the filter liner sent to the Facility had arrived and that they found 'waste outside the liner.' This is a violation of the Barnwell license.

"This notification is made in accordance with the New York State PSC [Public Service Commission] requirements per corporate procedure.

"Ref: CR-IP2-2005-00613"

The licensee will inform the State of New York and had informed the NRC Resident Inspector.

AUTOMATIC REACTOR SCRAM DUE TO A LOAD REJECTION

The following text was obtained from the licensee via facsimile:

"At 1629 [hrs. CST] on 02/11/05, Unit 3 reactor scrammed from 100% power when the output breaker tripped causing a load reject. The breaker tripped due to a corresponding switchyard breaker 5268 tripping when a PK block was re-installed before the trip cutout (TCO) switches were placed in TCO. All rods inserted. Unit 2 was also at 100% power and was unaffected by this event. Water level lowered to +1" as expected and was recovered by normal feed water flow. All expected PCIS [Primary Containment Isolation System] isolations, Group 2 (RHR S/D [Residual Heat Removal] cooling), Group 3 (RWCU [Reactor Water Clean Up]), Group 6 (ventilation), and group 8 (TIP [Transverse Incore Probe]) were received along with the auto start of CREV [Control Room Emergency Ventilation] and the 3 SGT [Standby Gas Treatment] trains. Four MSRV's [Main Steam Safety Relief Valves] lifted momentarily to stabilize reactor pressure.

"This event is reportable as a 4-hour and 8-hour Non-Emergency Notification along with a 60-day written report in accordance with 10CFR50.72(b)(2)(iv)(B), 10CFR50.72(b)(3)(iv)(A) and 10CFR50.73(a)(2)(iv)(A) as 'Any event or condition that results in a valid actuation of RPS [Reactor Protection System] and PCIS .."

The plant was performing restoration from switchyard maintenance at the time of the scram. All safety relief valves that lifted properly re-seated. Decay heat is being removed via the steam bypass valves to condenser. The electrical grid is stable.

The licensee has notified the NRC Resident Inspector.

RPS ACTUATION

The following text was obtained from the licensee via facsimile:

"At approximately 1959 hours Central Standard Time, Grand Gulf Nuclear Station experienced a loss of Electrical Bus 11R. This caused a loss of additional electrical buses, and a subsequent reactor scram on low reactor water [level]. The feedwater system was lost, and reactor low level 2 was reached. The Reactor Core Isolation Cooling System and High Pressure Core Spray System injected into the reactor and restored reactor water level. A primary containment, secondary containment, and drywell isolation occurred as expected. The Division 1 Diesel started and picked up the Division 1 bus. The Division 3 Diesel Generator started on the reactor low water level 2. The condenser is removing decay heat. The plant status currently is stable, with normal reactor water level and feedwater restored. All control rods inserted. The cause for the loss of Bus 11R is under investigation. Safety systems appeared to function as designed."

The licensee notified the NRC Resident Inspector.

POSTULATED LOSS OF AFW PUMPS FOLLOWING TORNADO DAMAGE TO CONDENSATE STORAGE TANK

"Plant engineering staff discovered that the auxiliary feedwater (AFW) system discharge pressure trip protective equipment may not operate to protect the AFW pumps from condensate storage tanks (CST) failing from a tornado event. The AFW system protection design uses discharge pressure switches to protect the AFW pumps from a loss of suction pressure. The AFW system is required equipment to support a plant shutdown which is also assumed to occur as a result of a tornado.

"Current analysis predicts substantial damage to the CSTs caused by a tornado. The CSTs are aligned as the AFW pumps' initial/preferred water source. The tank damage is predicted to result in a rapid, near complete, loss of water inventory due to a tornado. The CST volume loss quickly causes air to enter the pump suction piping to all three AFW pumps. Under the postulated conditions, the current discharge pressure switch design does not act fast enough to trip the pumps before significant pump damage can occur, it appears that the original design analyses failed to consider the consequences of a loss of suction source causing air to enter the pump suction.

"The design basis for AFW pump discharge pressure switches, in part, is assumed to protect the AFW pumps from damage due to a tornado. Given the event postulated as described, the pressure switches may not meet this design basis assumption. Therefore, all three AFW pump discharge pressure switches were declared inoperable at 2226 on 2/11/2005.

"To ensure the AFW Pumps are protected in the event of a tornado, compensatory actions were incorporated in Operating Procedure E-0-05 Response to Natural Events. At the earliest indication of a tornado threat (i.e. Tornado Watch, Warning or Strike) operators are directed to align Service Water to the AFW Pump Suction to ensure adequate NPSH In the event of a loss of the CST supply. These actions do not replace the automatic function but ensure the pumps are protected against loss of NPSH. Based on the proceduralized compensatory actions put in place, the AFW Pump Low discharge Pressure Trips were declared Operable but Non-Conforming at 0056 on 2/12/2005."

The licensee has notified the NRC Resident Inspector.