United States Nuclear Regulatory Commission - Protecting People and the Environment
Home > NRC Library > Document Collections > Reports Associated with Events > Event Notification Reports > 2004 > November 2

Event Notification Report for November 2, 2004

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
11/01/2004 - 11/02/2004

** EVENT NUMBERS **


41164 41165

To top of page
Power Reactor Event Number: 41164
Facility: RIVER BEND
Region: 4 State: LA
Unit: [1] [ ] [ ]
RX Type: [1] GE-6
NRC Notified By: DAVID CLYMER
HQ OPS Officer: CHAUNCEY GOULD
Notification Date: 11/01/2004
Notification Time: 02:13 [ET]
Event Date: 10/31/2004
Event Time: 22:56 [CDT]
Last Update Date: 11/01/2004
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
GARY SANBORN (R4)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N N 0 Refueling 0 Refueling

Event Text

PLANT HAD AUTO START OF THE DIVISION 1 EMERGENCY DIESEL GENERATOR

"Undervoltage conditions were experienced on Division 1 emergency switchgear with subsequent start and load of the respective diesel generator [EDG]. A preliminary investigation indicates that an unexpected undervoltage signal was generated when technicians inadvertently contacted the wrong terminals during preparations for the respective division ECCS surveillance testing. All systems and equipment responded as required."

Power is still being provided (as of event reporting time) by the Division 1 EDG while they are working to restore normal power.

The licensee notified the NRC Resident Inspector.

To top of page
Power Reactor Event Number: 41165
Facility: RIVER BEND
Region: 4 State: LA
Unit: [1] [ ] [ ]
RX Type: [1] GE-6
NRC Notified By: J. M. CLARK
HQ OPS Officer: MIKE RIPLEY
Notification Date: 11/01/2004
Notification Time: 23:44 [ET]
Event Date: 11/01/2004
Event Time: 16:44 [CST]
Last Update Date: 11/02/2004
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
CHUCK CAIN (R4)
TONY VEGEL (R4)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N N 0 Refueling 0 Refueling

Event Text

EMERGENCY DIESEL GENERATOR AUTOMATIC START

"At 1644 [11/01/04], with River Bend Station in Mode 5 (Refueling), voltage on offsite power line Reserve Station Service (RSS) No. 2 was lost. This offsite power line is the 230 KV power supply to the Division 2, 4160 volt safety related electrical bus. The Division 2 emergency diesel generator (EDG) automatically started and loaded on a loss of voltage to the 4160 volt safety bus.

"At the time of the event, Division 2 Residual Heat Removal (RHR) was in the fuel pool cooling assist mode and the pump secured due to the loss of power. It was subsequently restarted and continues to provide the shutdown cooling function.

"The following systems were isolated as a result of this event: Reactor Water Clean-up, Alternate Decay Heat Removal, and Floor Drains.

"Investigation of the cause of the event is ongoing."

There was no impact on spent fuel pool level or temperature. At the event reporting time, power to the bus was still being provided by the Division 2 EDG with plans to restore normal power shortly. The licensee informed the NRC Resident Inspector. See also similar event EN # 41164 of 10/31/04.

Page Last Reviewed/Updated Friday, March 30, 2012
Friday, March 30, 2012