Event Notification Report for May 27, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/26/2011 - 05/27/2011
Power Reactor
Event Number: 46899
Facility: SUMMER
Region: 2 State: SC
Unit: [1] [] []
RX Type: [1] W-3-LP
NRC Notified By: ERIC RUMFELT
HQ OPS Officer: JOHN KNOKE
Region: 2 State: SC
Unit: [1] [] []
RX Type: [1] W-3-LP
NRC Notified By: ERIC RUMFELT
HQ OPS Officer: JOHN KNOKE
Notification Date: 05/27/2011
Notification Time: 14:50 [ET]
Event Date: 05/27/2011
Event Time: 12:00 [EDT]
Last Update Date: 05/27/2011
Notification Time: 14:50 [ET]
Event Date: 05/27/2011
Event Time: 12:00 [EDT]
Last Update Date: 05/27/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(A) - ECCS INJECTION 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(2)(iv)(A) - ECCS INJECTION 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 |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Hot Standby | 0 | Hot Standby |
SAFETY INJECTION INITIATED DUE TO A HIGH DIFFERENTIAL PRESSURE BETWEEN MAIN STEAM LINES
"At 1200 hours on May 27, 2011, the plant was in Mode 3 during startup from a refueling outage with the main steam isolation valves closed. When the 'C' main steam isolation valve was opened for stroke testing, a safety injection occurred. The safety injection was due to a differential pressure of greater than 97 PSIG between the 'C' main steam line and the other main steam lines. The emergency core cooling system started and injected water into the Reactor Coolant System. All systems responded as expected. Safety injection was secured and the plant was stabilized in Mode 3."
The licensee has notified the NRC Resident Inspector. Licensee will be notifying the State and local government.
"At 1200 hours on May 27, 2011, the plant was in Mode 3 during startup from a refueling outage with the main steam isolation valves closed. When the 'C' main steam isolation valve was opened for stroke testing, a safety injection occurred. The safety injection was due to a differential pressure of greater than 97 PSIG between the 'C' main steam line and the other main steam lines. The emergency core cooling system started and injected water into the Reactor Coolant System. All systems responded as expected. Safety injection was secured and the plant was stabilized in Mode 3."
The licensee has notified the NRC Resident Inspector. Licensee will be notifying the State and local government.
Power Reactor
Event Number: 46900
Facility: DIABLO CANYON
Region: 4 State: CA
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ANTHONY CHITWOOD
HQ OPS Officer: HOWIE CROUCH
Region: 4 State: CA
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ANTHONY CHITWOOD
HQ OPS Officer: HOWIE CROUCH
Notification Date: 05/27/2011
Notification Time: 20:12 [ET]
Event Date: 05/27/2011
Event Time: 12:12 [PDT]
Last Update Date: 05/27/2011
Notification Time: 20:12 [ET]
Event Date: 05/27/2011
Event Time: 12:12 [PDT]
Last Update Date: 05/27/2011
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):
MARK HAIRE (R4DO)
MARK HAIRE (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
LOSS OF UNIT 1 STARTUP POWER RESULTS IN STARTING ALL EMERGENCY DIESEL GENERATORS
"On May 27, 2011, at 1212 PDT, Unit 1 startup power was lost due to actuation of startup transformer 1-1 overcurrent/differential relay 51-87UT11-1, which isolated the 12 kV feeder to startup bus. The loss of offsite startup power caused all Unit 1 emergency diesel generators (EDGs) to start in the standby mode. The EDGs started as designed with no issues observed. No vital loads were affected as a result of the 12 kV bus loss. On May 27, 2011, at 1241 PDT, all Unit 1 EDGs were shut down and returned to auto. Subsequently, startup transformers 1-1 and 1-2 were energized, followed by the 12 kV underground loop, and on May 27, 2011, at 1337 PDT, Unit 1 startup power was declared operable.
"The cause of the event was a human performance error while attempting to test the startup transformer 2-1 overcurrent/differential relay. The maintenance electrical worker inadvertently installed a jumper on the overcurrent/differential relay for startup transformer 1-1.
"Unit 2 startup power was cleared at this time and there was no effect on Unit 2.
"The NRC Resident Inspector was notified."
"On May 27, 2011, at 1212 PDT, Unit 1 startup power was lost due to actuation of startup transformer 1-1 overcurrent/differential relay 51-87UT11-1, which isolated the 12 kV feeder to startup bus. The loss of offsite startup power caused all Unit 1 emergency diesel generators (EDGs) to start in the standby mode. The EDGs started as designed with no issues observed. No vital loads were affected as a result of the 12 kV bus loss. On May 27, 2011, at 1241 PDT, all Unit 1 EDGs were shut down and returned to auto. Subsequently, startup transformers 1-1 and 1-2 were energized, followed by the 12 kV underground loop, and on May 27, 2011, at 1337 PDT, Unit 1 startup power was declared operable.
"The cause of the event was a human performance error while attempting to test the startup transformer 2-1 overcurrent/differential relay. The maintenance electrical worker inadvertently installed a jumper on the overcurrent/differential relay for startup transformer 1-1.
"Unit 2 startup power was cleared at this time and there was no effect on Unit 2.
"The NRC Resident Inspector was notified."