Event Notification Report for September 29, 2006
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
09/28/2006 - 09/29/2006
EVENT NUMBERS
43012
Power Reactor
Event Number: 43012
Facility: RIVER BEND
Region: 4 State: LA
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: DANNY WILLIAMSON
HQ OPS Officer: BILL GOTT
Region: 4 State: LA
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: DANNY WILLIAMSON
HQ OPS Officer: BILL GOTT
Notification Date: 11/27/2006
Notification Time: 10:35 [ET]
Event Date: 09/29/2006
Event Time: 13:33 [CDT]
Last Update Date: 11/27/2006
Notification Time: 10:35 [ET]
Event Date: 09/29/2006
Event Time: 13:33 [CDT]
Last Update Date: 11/27/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
Person (Organization):
RUSSELL BYWATER (R4)
RUSSELL BYWATER (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
INVALID SPECIFIC SYSTEM ACTUATION
"On September 29, 2006, at 1:33 pm CDT, a safety-related 120VAC distribution panel was inadvertently de-energized during a planned shift of its power supply. The plant was operating at 100 percent power at the time. The loss of power resulted in the automatic closure of primary containment isolation valves in the reactor water cleanup and the suppression pool cooling/cleanup systems. This event is being reported in accordance with 10CFR50.73(a)(1) as an invalid actuation of the containment isolation valves affecting more than one system.
"This event occurred during a planned shift of the inverters that supply the distribution panel. This shift was being performed to support post-maintenance testing of one of the inverters. The operators performing the shift were utilizing the appropriate procedure. At a certain point in the procedure, the off-going inverter was deenergized, and the operators discussed the expected equipment response. Following that discussion, a step was erroneously performed out of sequence, resulting in the loss of power to the 120VAC distribution panel. The primary containment isolation signal was actuated as designed, and the appropriate valves responded correctly.
"Reactor power was not affected by the containment isolation signal. The pertinent response procedures were implemented, and actions were taken to restore the distribution panel to service. This was completed at 5:31 pm CDT that day."
The licensee will notify the NRC Resident Inspector.
"On September 29, 2006, at 1:33 pm CDT, a safety-related 120VAC distribution panel was inadvertently de-energized during a planned shift of its power supply. The plant was operating at 100 percent power at the time. The loss of power resulted in the automatic closure of primary containment isolation valves in the reactor water cleanup and the suppression pool cooling/cleanup systems. This event is being reported in accordance with 10CFR50.73(a)(1) as an invalid actuation of the containment isolation valves affecting more than one system.
"This event occurred during a planned shift of the inverters that supply the distribution panel. This shift was being performed to support post-maintenance testing of one of the inverters. The operators performing the shift were utilizing the appropriate procedure. At a certain point in the procedure, the off-going inverter was deenergized, and the operators discussed the expected equipment response. Following that discussion, a step was erroneously performed out of sequence, resulting in the loss of power to the 120VAC distribution panel. The primary containment isolation signal was actuated as designed, and the appropriate valves responded correctly.
"Reactor power was not affected by the containment isolation signal. The pertinent response procedures were implemented, and actions were taken to restore the distribution panel to service. This was completed at 5:31 pm CDT that day."
The licensee will notify the NRC Resident Inspector.