Event Notification Report for December 27, 2008
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/26/2008 - 12/27/2008
EVENT NUMBERS
44743
Power Reactor
Event Number: 44743
Facility: BRAIDWOOD
Region: 3 State: IL
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MIKE DEBOARD
HQ OPS Officer: VINCE KLCO
Region: 3 State: IL
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MIKE DEBOARD
HQ OPS Officer: VINCE KLCO
Notification Date: 12/27/2008
Notification Time: 18:36 [ET]
Event Date: 12/27/2008
Event Time: 14:18 [CST]
Last Update Date: 12/27/2008
Notification Time: 18:36 [ET]
Event Date: 12/27/2008
Event Time: 14:18 [CST]
Last Update Date: 12/27/2008
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):
ANN MARIE STONE (R3)
ANN MARIE STONE (R3)
| 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 |
AUTOMATIC REACTOR TRIP AS A RESULT OF A GENERATOR TRIP
"At 1418 on 12-27-08 Braidwood Unit 2 experienced an automatic Reactor Trip. The Reactor Trip red first out annunciator was Turb[ine] Trip above P8 Rx Trip. At the time of the trip the Unit Aux Transformer [UAT] 241-1 sudden pressure relay actuated causing a main generator trip which resulted in a main turbine trip which resulted in a Reactor Trip. Also at the same time as the Reactor Trip, the 2C Heater Drain Pump tripped on phase A over current. Damage was subsequently noted on the pump motor terminal box. No fire or smoke was observed at UAT 241-1 or the 2C Heater Drain Pump.
"After the Reactor Trip occurred, all four steam generators reached their low-2 Reactor Trip setpoints and the pressurizer reached its low pressure Reactor Trip setpoint all of which is an expected response on a trip from full power. Steam generator levels and pressurizer pressure have been restored. Both the 2A and the 2B Auxiliary Feedwater Pumps auto started on the low-2 steam generator levels as expected. All control rods fully inserted into the core.
"No secondary relief valves lifted and no secondary steam was released as a result of the Reactor Trip. Steam generators are now being filled by the Startup Feedwater Pump and the Auxiliary Feedwater Pumps have been placed in standby. The main steam dumps are in service to the main condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature.
"This report is being made per 10CFR 50.72(b)(2)(iv)(B) for RPS actuation, 4 hr [notification], and per 10CFR 50.72(b)(3)(iv)(A) for automatic actuation of the Auxiliary Feedwater System, 8 hr [notification]."
The electrical line up transferred to the normal shutdown configuration with standby diesel generators and safety systems available. There was no impact on Unit 1.
The licensee plans on issuing a press release and has notified the NRC Resident Inspector.
"At 1418 on 12-27-08 Braidwood Unit 2 experienced an automatic Reactor Trip. The Reactor Trip red first out annunciator was Turb[ine] Trip above P8 Rx Trip. At the time of the trip the Unit Aux Transformer [UAT] 241-1 sudden pressure relay actuated causing a main generator trip which resulted in a main turbine trip which resulted in a Reactor Trip. Also at the same time as the Reactor Trip, the 2C Heater Drain Pump tripped on phase A over current. Damage was subsequently noted on the pump motor terminal box. No fire or smoke was observed at UAT 241-1 or the 2C Heater Drain Pump.
"After the Reactor Trip occurred, all four steam generators reached their low-2 Reactor Trip setpoints and the pressurizer reached its low pressure Reactor Trip setpoint all of which is an expected response on a trip from full power. Steam generator levels and pressurizer pressure have been restored. Both the 2A and the 2B Auxiliary Feedwater Pumps auto started on the low-2 steam generator levels as expected. All control rods fully inserted into the core.
"No secondary relief valves lifted and no secondary steam was released as a result of the Reactor Trip. Steam generators are now being filled by the Startup Feedwater Pump and the Auxiliary Feedwater Pumps have been placed in standby. The main steam dumps are in service to the main condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature.
"This report is being made per 10CFR 50.72(b)(2)(iv)(B) for RPS actuation, 4 hr [notification], and per 10CFR 50.72(b)(3)(iv)(A) for automatic actuation of the Auxiliary Feedwater System, 8 hr [notification]."
The electrical line up transferred to the normal shutdown configuration with standby diesel generators and safety systems available. There was no impact on Unit 1.
The licensee plans on issuing a press release and has notified the NRC Resident Inspector.