Event Notification Report for December 20, 2008
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/19/2008 - 12/20/2008
Power Reactor
Event Number: 44737
Facility: PILGRIM
Region: 1 State: MA
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: R.M. PROBASCO
HQ OPS Officer: MARK ABRAMOVITZ
Region: 1 State: MA
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: R.M. PROBASCO
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 12/20/2008
Notification Time: 17:07 [ET]
Event Date: 12/20/2008
Event Time: 10:45 [EST]
Last Update Date: 12/20/2008
Notification Time: 17:07 [ET]
Event Date: 12/20/2008
Event Time: 10:45 [EST]
Last Update Date: 12/20/2008
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):
RICHARD BARKLEY (R1)
WILLIAM RULAND (NRR)
RICHARD BARKLEY (R1)
WILLIAM RULAND (NRR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Hot Shutdown | 0 | Hot Shutdown |
MOMENTARY LOSS OF 345KV OFFSITE POWER
"At approximately 1045 hours on Saturday, December 20, 2008, while in a Hot Shutdown condition, Pilgrim Station experienced a momentary loss of all 345kV off-site power to the Startup Transformer (SUT). As a result, the following safety system actuations occurred: automatic Reactor Protection System (RPS) actuation (all control rods were previously inserted), automatic start of both Emergency Diesel Generators (EDG) and loading of their respective emergency buses, automatic actuation of Primary Containment Isolation Systems (PCIS) Groups I, II, VI and Reactor Building Ventilation, manual initiation of the High Pressure Coolant Injection (HPCI) system for reactor pressure control, and manual initiation of the Reactor Core Isolation Cooling (RCIC) system for reactor level control. All systems functioned as designed and expected.
"Because power from an off-site source remained available from the 23kV Shutdown Transformer, the criteria for declaration of an Unusual Event were not met (Pilgrim EAL 6.3.2.1).
"345kV power was automatically restored to the Startup Transformer via breaker reclose logic. Restoration of normal on-site power to all 4kV buses is complete and efforts to return systems to normal shutdown alignments are in progress.
"Current plans are in place to maneuver the plant to a Cold Shutdown condition as necessary to support recovery actions.
"The NRC Resident was on-site at the time of the event and has been notified.
"There was no threat to the health or safety of the public as a result of this event."
The loss of power was caused by a breaker icing in the onsite switchyard. The switchyard breakers were inspected for icing.
The licensee notified the State of Massachusetts.
"At approximately 1045 hours on Saturday, December 20, 2008, while in a Hot Shutdown condition, Pilgrim Station experienced a momentary loss of all 345kV off-site power to the Startup Transformer (SUT). As a result, the following safety system actuations occurred: automatic Reactor Protection System (RPS) actuation (all control rods were previously inserted), automatic start of both Emergency Diesel Generators (EDG) and loading of their respective emergency buses, automatic actuation of Primary Containment Isolation Systems (PCIS) Groups I, II, VI and Reactor Building Ventilation, manual initiation of the High Pressure Coolant Injection (HPCI) system for reactor pressure control, and manual initiation of the Reactor Core Isolation Cooling (RCIC) system for reactor level control. All systems functioned as designed and expected.
"Because power from an off-site source remained available from the 23kV Shutdown Transformer, the criteria for declaration of an Unusual Event were not met (Pilgrim EAL 6.3.2.1).
"345kV power was automatically restored to the Startup Transformer via breaker reclose logic. Restoration of normal on-site power to all 4kV buses is complete and efforts to return systems to normal shutdown alignments are in progress.
"Current plans are in place to maneuver the plant to a Cold Shutdown condition as necessary to support recovery actions.
"The NRC Resident was on-site at the time of the event and has been notified.
"There was no threat to the health or safety of the public as a result of this event."
The loss of power was caused by a breaker icing in the onsite switchyard. The switchyard breakers were inspected for icing.
The licensee notified the State of Massachusetts.
Power Reactor
Event Number: 44736
Facility: ARKANSAS NUCLEAR
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: TIMOTHY STEWART
HQ OPS Officer: MARK ABRAMOVITZ
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: TIMOTHY STEWART
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 12/20/2008
Notification Time: 14:23 [ET]
Event Date: 12/20/2008
Event Time: 12:12 [CST]
Last Update Date: 12/20/2008
Notification Time: 14:23 [ET]
Event Date: 12/20/2008
Event Time: 12:12 [CST]
Last Update Date: 12/20/2008
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
Person (Organization):
GREG PICK (R4)
WILLIAM RULAND (NRR)
BRIAN McDERMOTT (IRD)
GREG PICK (R4)
WILLIAM RULAND (NRR)
BRIAN McDERMOTT (IRD)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 100 | Power Operation | 0 | Hot Standby |
MANUAL REACTOR TRIP WHEN CONTROL ROD BANK INSERTED WITHOUT OPERATOR ACTION
"Arkansas Nuclear one Unit 1 manually tripped from 100% power due to control rod mechanism group 7 unexpectedly dropping from 90% to 70%. No Primary safeties lifted. Secondary safeties lifted for approximately 1 minute. Emergency feedwater did not actuate and was not needed. Post trip response was normal and the plant is stable in mode 3. Post transient review is in progress."
All control rods fully inserted on the trip. The plant is in its normal shutdown electrical lineup. Steam generator level is being maintained using aux feed and steam is being dumped to the main condenser through the turbine bypass valves. There is no primary to secondary leakage.
The licensee notified the NRC Resident Inspector, the State of Arkansas, and the Arkansas Department of Health.
See similar event number 44716.
"Arkansas Nuclear one Unit 1 manually tripped from 100% power due to control rod mechanism group 7 unexpectedly dropping from 90% to 70%. No Primary safeties lifted. Secondary safeties lifted for approximately 1 minute. Emergency feedwater did not actuate and was not needed. Post trip response was normal and the plant is stable in mode 3. Post transient review is in progress."
All control rods fully inserted on the trip. The plant is in its normal shutdown electrical lineup. Steam generator level is being maintained using aux feed and steam is being dumped to the main condenser through the turbine bypass valves. There is no primary to secondary leakage.
The licensee notified the NRC Resident Inspector, the State of Arkansas, and the Arkansas Department of Health.
See similar event number 44716.