Event Notification Report for December 22, 2001
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/21/2001 - 12/22/2001
EVENT NUMBERS
38590
Power Reactor
Event Number: 38590
Facility: NORTH ANNA
Region: 2 State: VA
Unit: [] [2] []
RX Type: [1] W-3-LP,[2] W-3-LP
NRC Notified By: JAMES CROSSMAN
HQ OPS Officer: STEVE SANDIN
Region: 2 State: VA
Unit: [] [2] []
RX Type: [1] W-3-LP,[2] W-3-LP
NRC Notified By: JAMES CROSSMAN
HQ OPS Officer: STEVE SANDIN
Notification Date: 12/22/2001
Notification Time: 19:20 [ET]
Event Date: 12/22/2001
Event Time: 15:42 [EST]
Last Update Date: 12/22/2001
Notification Time: 19:20 [ET]
Event Date: 12/22/2001
Event Time: 15:42 [EST]
Last Update Date: 12/22/2001
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
LEONARD WERT (R2)
LEONARD WERT (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | A/R | Y | 100 | Power Operation | 0 | Hot Standby |
UNIT 2 EXPERIENCED A REACTOR TRIP/TURBINE TRIP DUE TO EHC SYSTEM LOSS OF POWER SUPPLY
The Unit 2 electro-hydraulic control (EHC) system power supply failed, causing a loss of electrical load. The resulting shrink in steam generator water level tripped the reactor on steam generator "1A" Lo-Lo level ("first out alarm indication"). A turbine trip on reactor trip occurred, as expected. All control rods fully inserted. Both AMSAC and the auxiliary feedwater (AFW) system actuated ( 2 motor-driven and the turbine-driven pump). However, normal feedwater remained in service and the AFW pumps have subsequently been returned to standby.
Unit 2 is currently stable in mode 3 with decay heat removal to the main condenser. No secondary safeties/atmospheric relief valves lifted. Abnormal indications during the transient included reactor coolant pump (RCP) "A" vibration alarm (cleared during transient), pressurizer power-operated relief valve (PORV) lifted/reseated and one Individual rod position indication (IRPI) indicator malfunctioned.
The licensee informed the NRC resident inspector.
The Unit 2 electro-hydraulic control (EHC) system power supply failed, causing a loss of electrical load. The resulting shrink in steam generator water level tripped the reactor on steam generator "1A" Lo-Lo level ("first out alarm indication"). A turbine trip on reactor trip occurred, as expected. All control rods fully inserted. Both AMSAC and the auxiliary feedwater (AFW) system actuated ( 2 motor-driven and the turbine-driven pump). However, normal feedwater remained in service and the AFW pumps have subsequently been returned to standby.
Unit 2 is currently stable in mode 3 with decay heat removal to the main condenser. No secondary safeties/atmospheric relief valves lifted. Abnormal indications during the transient included reactor coolant pump (RCP) "A" vibration alarm (cleared during transient), pressurizer power-operated relief valve (PORV) lifted/reseated and one Individual rod position indication (IRPI) indicator malfunctioned.
The licensee informed the NRC resident inspector.