Event Notification Report for October 07, 2012
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/06/2012 - 10/07/2012
EVENT NUMBERS
48388
Power Reactor
Event Number: 48388
Facility: SAINT LUCIE
Region: 2 State: FL
Unit: [] [2] []
RX Type: [1] CE,[2] CE
NRC Notified By: JACK BREEN
HQ OPS Officer: VINCE KLCO
Region: 2 State: FL
Unit: [] [2] []
RX Type: [1] CE,[2] CE
NRC Notified By: JACK BREEN
HQ OPS Officer: VINCE KLCO
Notification Date: 10/08/2012
Notification Time: 02:37 [ET]
Event Date: 10/07/2012
Event Time: 21:40 [EDT]
Last Update Date: 10/08/2012
Notification Time: 02:37 [ET]
Event Date: 10/07/2012
Event Time: 21:40 [EDT]
Last Update Date: 10/08/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
KATHLEEN O'DONOHUE (R2DO)
KATHLEEN O'DONOHUE (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Defueled | 0 | Defueled |
ESSENTIAL BUS DEENERGIZED WHILE DEFUELED
"On October 7, 2012, with Unit 2 in a defueled condition, a differential current lockout occurred on the 2B3 4.16kV essential bus, causing a deenergization of the 2B3 4.16kV essential bus. At the time of the event, the 2B Emergency Diesel Generator (EDG) was loaded to the essential bus. Due to the differential current lockout, all bus loads were lost and the 2B EDG output breaker feeding the essential bus opened and the 2B EDG transferred to emergency mode. The 2A EDG is operable and in standby. All equipment responded as expected. The plant is currently being maintained in a defueled condition. Decay heat removal is being supplied by the 2A Fuel Pool Cooling train. The cause of the differential current lockout of the 2B3 4.16kv bus is under investigation.
"This event is reportable pursuant to 10CFR 50.72(b)(3)(iv)(A)."
The licensee notified the NRC Resident Inspector.
"On October 7, 2012, with Unit 2 in a defueled condition, a differential current lockout occurred on the 2B3 4.16kV essential bus, causing a deenergization of the 2B3 4.16kV essential bus. At the time of the event, the 2B Emergency Diesel Generator (EDG) was loaded to the essential bus. Due to the differential current lockout, all bus loads were lost and the 2B EDG output breaker feeding the essential bus opened and the 2B EDG transferred to emergency mode. The 2A EDG is operable and in standby. All equipment responded as expected. The plant is currently being maintained in a defueled condition. Decay heat removal is being supplied by the 2A Fuel Pool Cooling train. The cause of the differential current lockout of the 2B3 4.16kv bus is under investigation.
"This event is reportable pursuant to 10CFR 50.72(b)(3)(iv)(A)."
The licensee notified the NRC Resident Inspector.