Event Notification Report for November 29, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/28/2011 - 11/29/2011
Power Reactor
Event Number: 47485
Facility: SOUTH TEXAS
Region: 4 State: TX
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ROBERT BRINKLEY
HQ OPS Officer: HOWIE CROUCH
Region: 4 State: TX
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ROBERT BRINKLEY
HQ OPS Officer: HOWIE CROUCH
Notification Date: 11/29/2011
Notification Time: 06:55 [ET]
Event Date: 11/29/2011
Event Time: 03:29 [CST]
Last Update Date: 11/29/2011
Notification Time: 06:55 [ET]
Event Date: 11/29/2011
Event Time: 03:29 [CST]
Last Update Date: 11/29/2011
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):
THOMAS FARNHOLTZ (R4DO)
THOMAS FARNHOLTZ (R4DO)
| 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 DUE TO TURBINE TRIP ON GENERATOR LOCKOUT
"At 0329 CST on 11/29/2011, Unit 2 experienced an automatic Reactor Trip while the plant was stable at 100% power in Mode 1. All systems actuated as designed. The reactor trip was caused by Generator Lockout.
"All ESF systems actuated as designed. The following systems actuated: Auxiliary Feedwater [AFW] and Feedwater Isolation.
"All control rods fully inserted. Steam Dump system valve FV 7485 failed open and was manually isolated. This caused a letdown isolation that was restored. No primary/secondary relief valves lifted. There were no electrical bus transfer problems. Normal operating temperature and pressure [of] 567 degrees F and 2235 psig [is being maintained]. There were no significant TS LCOs entered."
The electrical grid is stable and is supplying power to the plant via a normal shutdown electrical line-up. Decay heat is being removed via steam dumps to the condenser with AFW supplying the steam generators. There was no effect on Unit 1.
The licensee has notified the NRC Resident Inspector.
* * * UPDATE ON 11/29/11 AT 1312 EST FROM BRINKLY TO HUFFMAN * * *
The licensee has issued a press release concerning this event. The NRC Resident Inspector will be notified. R4DO (Farnholtz) informed.
"At 0329 CST on 11/29/2011, Unit 2 experienced an automatic Reactor Trip while the plant was stable at 100% power in Mode 1. All systems actuated as designed. The reactor trip was caused by Generator Lockout.
"All ESF systems actuated as designed. The following systems actuated: Auxiliary Feedwater [AFW] and Feedwater Isolation.
"All control rods fully inserted. Steam Dump system valve FV 7485 failed open and was manually isolated. This caused a letdown isolation that was restored. No primary/secondary relief valves lifted. There were no electrical bus transfer problems. Normal operating temperature and pressure [of] 567 degrees F and 2235 psig [is being maintained]. There were no significant TS LCOs entered."
The electrical grid is stable and is supplying power to the plant via a normal shutdown electrical line-up. Decay heat is being removed via steam dumps to the condenser with AFW supplying the steam generators. There was no effect on Unit 1.
The licensee has notified the NRC Resident Inspector.
* * * UPDATE ON 11/29/11 AT 1312 EST FROM BRINKLY TO HUFFMAN * * *
The licensee has issued a press release concerning this event. The NRC Resident Inspector will be notified. R4DO (Farnholtz) informed.
Power Reactor
Event Number: 47489
Facility: CLINTON
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: KEN LEFFEL
HQ OPS Officer: STEVE SANDIN
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: KEN LEFFEL
HQ OPS Officer: STEVE SANDIN
Notification Date: 11/29/2011
Notification Time: 21:47 [ET]
Event Date: 11/29/2011
Event Time: 17:28 [CST]
Last Update Date: 11/29/2011
Notification Time: 21:47 [ET]
Event Date: 11/29/2011
Event Time: 17:28 [CST]
Last Update Date: 11/29/2011
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):
KENNETH RIEMER (R3DO)
KENNETH RIEMER (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 16 | Power Operation | 0 | Hot Shutdown |
UNIT EXPERIENCED AN AUTOMATIC REACTOR SCRAM DURING A PLANNED SHUTDOWN
"During a planned shutdown in preparation for refueling outage C1R13, shortly after tripping the main turbine, an automatic reactor scram occurred due to high reactor steam dome pressure. Preliminarily, per the plant process computer, the reactor pressure was observed to reach approximately 1074 psig approximately 26 seconds after main steam bypass valves unexpectedly closed. An investigation will be conducted to determine the cause of the bypass valve closure and reactor scram. No safety relief valves lifted as a result of the pressure increase.
"This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) as an event or condition that results in actuation of the reactor protection system when the reactor was critical."
The licensee is manually controlling the steam bypass valves to remove decay heat via the main condenser. All control rods fully inserted. The Unit is in a normal shutdown electrical lineup.
The licensee informed the NRC Resident Inspector.
"During a planned shutdown in preparation for refueling outage C1R13, shortly after tripping the main turbine, an automatic reactor scram occurred due to high reactor steam dome pressure. Preliminarily, per the plant process computer, the reactor pressure was observed to reach approximately 1074 psig approximately 26 seconds after main steam bypass valves unexpectedly closed. An investigation will be conducted to determine the cause of the bypass valve closure and reactor scram. No safety relief valves lifted as a result of the pressure increase.
"This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) as an event or condition that results in actuation of the reactor protection system when the reactor was critical."
The licensee is manually controlling the steam bypass valves to remove decay heat via the main condenser. All control rods fully inserted. The Unit is in a normal shutdown electrical lineup.
The licensee informed the NRC Resident Inspector.