Event Notification Report for November 02, 2002
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/01/2002 - 11/02/2002
EVENT NUMBERS
39340
Power Reactor
Event Number: 39340
Facility: SAN ONOFRE
Region: 4 State: CA
Unit: [] [2] []
RX Type: [1] W-3-LP,[2] CE,[3] CE
NRC Notified By: BOB CONOSCENTI
HQ OPS Officer: GERRY WAIG
Region: 4 State: CA
Unit: [] [2] []
RX Type: [1] W-3-LP,[2] CE,[3] CE
NRC Notified By: BOB CONOSCENTI
HQ OPS Officer: GERRY WAIG
Notification Date: 11/02/2002
Notification Time: 08:38 [ET]
Event Date: 11/02/2002
Event Time: 03:16 [PST]
Last Update Date: 11/02/2002
Notification Time: 08:38 [ET]
Event Date: 11/02/2002
Event Time: 03:16 [PST]
Last Update Date: 11/02/2002
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
Person (Organization):
CLAUDE JOHNSON (R4)
CLAUDE JOHNSON (R4)
| 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 REACTOR TRIP ON LOW STEAM GENERATOR WATER LEVEL
The San Onofre Unit 2 reactor tripped from full power on reactor protection system (RPS) actuation due to low steam generator (SG) 2E089 water level. The low SG water level was caused by the momentary closure of main feedwater regulator valve 2-FV-1111. The momentary valve closure caused the #1 SG water level to drop to the ESFAS/reactor trip setpoint of 21% (NR) resulting in RPS actuation, automatic auxiliary feedwater system initiation, and the trip of both main feedwater pumps. The auxiliary feedwater system was used to restore and maintain SG water levels after the reactor trip. All control rods fully inserted into the reactor and all plant systems responded to the event as expected. The plant is currently stable in hot standby conditions.
The licensee notified the NRC Resident Inspector.
The San Onofre Unit 2 reactor tripped from full power on reactor protection system (RPS) actuation due to low steam generator (SG) 2E089 water level. The low SG water level was caused by the momentary closure of main feedwater regulator valve 2-FV-1111. The momentary valve closure caused the #1 SG water level to drop to the ESFAS/reactor trip setpoint of 21% (NR) resulting in RPS actuation, automatic auxiliary feedwater system initiation, and the trip of both main feedwater pumps. The auxiliary feedwater system was used to restore and maintain SG water levels after the reactor trip. All control rods fully inserted into the reactor and all plant systems responded to the event as expected. The plant is currently stable in hot standby conditions.
The licensee notified the NRC Resident Inspector.