Event Notification Report for November 18, 2000
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/17/2000 - 11/18/2000
EVENT NUMBERS
37533
Power Reactor
Event Number: 37533
Facility: PALO VERDE
Region: 4 State: AZ
Unit: [] [2] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: RUSSELL A. STROUD
HQ OPS Officer: STEVE SANDIN
Region: 4 State: AZ
Unit: [] [2] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: RUSSELL A. STROUD
HQ OPS Officer: STEVE SANDIN
Notification Date: 11/18/2000
Notification Time: 17:36 [ET]
Event Date: 11/18/2000
Event Time: 11:47 [MST]
Last Update Date: 11/18/2000
Notification Time: 17:36 [ET]
Event Date: 11/18/2000
Event Time: 11:47 [MST]
Last Update Date: 11/18/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
Person (Organization):
TOM ANDREWS (R4)
TOM ANDREWS (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | A/R | Y | 45 | Power Operation | 0 | Hot Standby |
UNIT 2 EXPERIENCED AN AUTOMATIC REACTOR TRIP FOLLOWING A REACTOR POWER CUTBACK
"On November 18, 2000, at approximately 1147 MST, Palo Verde Unit 2 experienced an automatic reactor trip (RPS actuation) from approximately 45% rated thermal power. Unit 2 is stable at normal operating temperature and pressure in Mode 3. The event did not result in any challenges to the fission product barrier. There were no adverse safety consequences or implications as a result of this event. The event did not adversely affect the safe operation of the plant or the health and safety of the public.
"Prior to the reactor trip, at approximately 1008 MST, Unit 2 was at 100 percent power and normal operating temperature and pressure, when testing began to validate various parts of the electrical generator and exciter model parameters. At approximately 1059 MST, Unit 2 experienced a generator/turbine trip. Steam bypass control valves opened and a reactor power cutback was initiated.
"Operations personnel were in the process of plant stabilization after the reactor power cutback, when at approximately 1147 MST, the reactor tripped. All control element assemblies (CEAs) inserted as required and the trip was classified as uncomplicated with respect to the emergency plan. The primary plant is now stabilized in Mode 3 in forced circulation with both steam generators being used for heat removal,
"The cause of the reactor trip has not been determined and is under investigation at this time. APS [Arizona Public Service] will supplement this report if information is developed which significantly alters this information."
The licensee informed the NRC resident inspector.
"On November 18, 2000, at approximately 1147 MST, Palo Verde Unit 2 experienced an automatic reactor trip (RPS actuation) from approximately 45% rated thermal power. Unit 2 is stable at normal operating temperature and pressure in Mode 3. The event did not result in any challenges to the fission product barrier. There were no adverse safety consequences or implications as a result of this event. The event did not adversely affect the safe operation of the plant or the health and safety of the public.
"Prior to the reactor trip, at approximately 1008 MST, Unit 2 was at 100 percent power and normal operating temperature and pressure, when testing began to validate various parts of the electrical generator and exciter model parameters. At approximately 1059 MST, Unit 2 experienced a generator/turbine trip. Steam bypass control valves opened and a reactor power cutback was initiated.
"Operations personnel were in the process of plant stabilization after the reactor power cutback, when at approximately 1147 MST, the reactor tripped. All control element assemblies (CEAs) inserted as required and the trip was classified as uncomplicated with respect to the emergency plan. The primary plant is now stabilized in Mode 3 in forced circulation with both steam generators being used for heat removal,
"The cause of the reactor trip has not been determined and is under investigation at this time. APS [Arizona Public Service] will supplement this report if information is developed which significantly alters this information."
The licensee informed the NRC resident inspector.