Event Notification Report for March 15, 2014
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
03/14/2014 - 03/15/2014
EVENT NUMBERS
49919
Power Reactor
Event Number: 49919
Facility: BYRON
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BLAINE PETERS
HQ OPS Officer: DONG HWA PARK
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BLAINE PETERS
HQ OPS Officer: DONG HWA PARK
Notification Date: 03/15/2014
Notification Time: 14:56 [ET]
Event Date: 03/15/2014
Event Time: 11:02 [CDT]
Last Update Date: 03/15/2014
Notification Time: 14:56 [ET]
Event Date: 03/15/2014
Event Time: 11:02 [CDT]
Last Update Date: 03/15/2014
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):
DAVE PASSEHL (R3DO)
DAVE PASSEHL (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling | 0 | Refueling |
MOMENTARY LOSS OF SHUTDOWN COOLING DUE TO A LOSS OF OFFSITE POWER
"[Unit] 1 experienced a loss of offsite power (LOOP). [Unit] 1 station aux transformers (SATs) tripped. 1A and 1B emergency diesel generators (EDGs) started and properly restored power to ESF [engineered safety feature] bus 141 and 142. Safe shutdown loads (1A/B SX [essential service water] pumps and 1A/B CC [component cooling] pumps) properly started when signaled by the EDG sequencers. The 1A residual heat removal pump was manually restarted at 1105 [CDT] to restore shutdown cooling. There was no impact to RCS temperature. Additionally, a containment isolation signal was actuated when containment radiation monitors which are powered from the ESF buses briefly lost power until restored by the EDGs. All related equipment realigned as expected except for the 0A VC [control room] chiller that didn't start when required on the EDG sequencer. The cause of the LOOP and the 0A VC chiller issue is under investigation. Fuel moves were in progress and stopped safely. All fuel bundles are in a safe location."
Unit 2 was not affected and remains in mode 1.
The licensee has notified the NRC Resident Inspector.
"[Unit] 1 experienced a loss of offsite power (LOOP). [Unit] 1 station aux transformers (SATs) tripped. 1A and 1B emergency diesel generators (EDGs) started and properly restored power to ESF [engineered safety feature] bus 141 and 142. Safe shutdown loads (1A/B SX [essential service water] pumps and 1A/B CC [component cooling] pumps) properly started when signaled by the EDG sequencers. The 1A residual heat removal pump was manually restarted at 1105 [CDT] to restore shutdown cooling. There was no impact to RCS temperature. Additionally, a containment isolation signal was actuated when containment radiation monitors which are powered from the ESF buses briefly lost power until restored by the EDGs. All related equipment realigned as expected except for the 0A VC [control room] chiller that didn't start when required on the EDG sequencer. The cause of the LOOP and the 0A VC chiller issue is under investigation. Fuel moves were in progress and stopped safely. All fuel bundles are in a safe location."
Unit 2 was not affected and remains in mode 1.
The licensee has notified the NRC Resident Inspector.