Event Notification Report for November 22, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/21/2011 - 11/22/2011
Power Reactor
Event Number: 47471
Facility: COOPER
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: BRIAN STANDER
HQ OPS Officer: HOWIE CROUCH
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: BRIAN STANDER
HQ OPS Officer: HOWIE CROUCH
Notification Date: 11/22/2011
Notification Time: 18:50 [ET]
Event Date: 11/22/2011
Event Time: 13:53 [CST]
Last Update Date: 11/22/2011
Notification Time: 18:50 [ET]
Event Date: 11/22/2011
Event Time: 13:53 [CST]
Last Update Date: 11/22/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
RAY AZUA (R4DO)
RAY AZUA (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
INADVERTENT ACTUATION OF A DRYWELL-TO-SUPPRESSION CHAMBER VACUUM RELIEF VALVE
"This report is being made pursuant to 10CFR50.72 criteria (b)(3)(v)(D), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.'
"At time 1353 CST on 11/22/11, a licensed operator inadvertently bumped the Torus-to-Drywell vacuum relief Master Control Switch for the Drywell-to-Suppression Chamber vacuum relief valves from the 'close' position to the 'open' position. One of the twelve vacuum relief valves controlled by the Master Control Switch indicated an open indication. The other eleven vacuum relief valves did not operate due to having the pneumatics secured to the operator. Immediately upon recognizing the condition, the licensed operator returned the switch to the closed position. The open vacuum relief valve indication changed to the closed indication. From automatic alarm logging, the time that the vacuum relief was open was recorded as six seconds. The vacuum relief valve has a safety function in the closed position to limit the amount of bypass flow to ensure proper containment response on a postulated LOCA event and an open safety function post-LOCA to limit negative differential pressure between the drywell and the suppression chamber. With the valve partially open, the LOCA containment response cannot be assured. This results in declaring the primary containment inoperable.
"The vacuum relief valve manual operators have air secured during normal operation. With air secured, only one of the twelve valves operated versus all twelve. A valve line-up was performed and all pneumatic supply valves were in the proper line-up. Currently, the only unusual occurrence is why there was sufficient air to the individual vacuum relief valve that caused it to operate in the open direction. This will be resolved within the corrective action program.
"Currently, all twelve Drywell-to-Suppression Chamber vacuum relief valves are closed and in the normal line-up.
"[The] NRC Senior Resident Inspector has been notified."
"This report is being made pursuant to 10CFR50.72 criteria (b)(3)(v)(D), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.'
"At time 1353 CST on 11/22/11, a licensed operator inadvertently bumped the Torus-to-Drywell vacuum relief Master Control Switch for the Drywell-to-Suppression Chamber vacuum relief valves from the 'close' position to the 'open' position. One of the twelve vacuum relief valves controlled by the Master Control Switch indicated an open indication. The other eleven vacuum relief valves did not operate due to having the pneumatics secured to the operator. Immediately upon recognizing the condition, the licensed operator returned the switch to the closed position. The open vacuum relief valve indication changed to the closed indication. From automatic alarm logging, the time that the vacuum relief was open was recorded as six seconds. The vacuum relief valve has a safety function in the closed position to limit the amount of bypass flow to ensure proper containment response on a postulated LOCA event and an open safety function post-LOCA to limit negative differential pressure between the drywell and the suppression chamber. With the valve partially open, the LOCA containment response cannot be assured. This results in declaring the primary containment inoperable.
"The vacuum relief valve manual operators have air secured during normal operation. With air secured, only one of the twelve valves operated versus all twelve. A valve line-up was performed and all pneumatic supply valves were in the proper line-up. Currently, the only unusual occurrence is why there was sufficient air to the individual vacuum relief valve that caused it to operate in the open direction. This will be resolved within the corrective action program.
"Currently, all twelve Drywell-to-Suppression Chamber vacuum relief valves are closed and in the normal line-up.
"[The] NRC Senior Resident Inspector has been notified."
Power Reactor
Event Number: 47472
Facility: PALO VERDE
Region: 4 State: AZ
Unit: [1] [] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: BRAD EKLUND
HQ OPS Officer: DONALD NORWOOD
Region: 4 State: AZ
Unit: [1] [] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: BRAD EKLUND
HQ OPS Officer: DONALD NORWOOD
Notification Date: 11/22/2011
Notification Time: 23:03 [ET]
Event Date: 11/22/2011
Event Time: 19:25 [MST]
Last Update Date: 11/22/2011
Notification Time: 23:03 [ET]
Event Date: 11/22/2011
Event Time: 19:25 [MST]
Last Update Date: 11/22/2011
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):
RAY AZUA (R4DO)
RAY AZUA (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 1 | Startup | 0 | Hot Standby |
MANUAL REACTOR TRIP DUE TO CONTROL ELEMENT DEVIATION
"The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
"PVNGS [Palo Verde Nuclear Generating Station] [Unit 1 was in the process of Low Power Physics Testing following a refueling outage. The Unit was at 0.4 percent power and performing individual CEA [Control Element Assembly] group worth testing. Specifically Regulating Group (RG) 2 was being inserted while RG 4 was being withdrawn. During the CEA manipulations, it was identified that there was a CEA deviation on RG 2 subgroup 17 that exceeded 6 inches from the remainder of the RG. RG 2 subgroup 18 was at 134 inches withdrawn and RG 2 subgroup 17 had two CEAs at 124 inches, one CEA at 122 inches and one CEA at 118 inches withdrawn. The CEA Malfunctions abnormal operating procedure 40AO-9ZZ11 was entered and a manual reactor trip was directed by the Control Room Supervisor. The reactor was tripped at 1925 hours.
"Unit 1 was at normal temperature and pressure prior to the trip. All CEAs inserted fully into the reactor core. This was an uncomplicated reactor trip. No ESF actuations occurred and none were required. Safety related buses remained energized during and following the reactor trip. The offsite power grid is stable. No significant LCOs have been entered as a result of this event. There was no loss of normal heat removal capabilities, or loss of any safety functions associated with this event. No major equipment was inoperable prior to the event that contributed to the event. The event did not result in any challenges to fission product barriers and there were no adverse safety consequences 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.
"The NRC Resident Inspector was informed of the Unit 1 reactor trip and this notification."
"The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
"PVNGS [Palo Verde Nuclear Generating Station] [Unit 1 was in the process of Low Power Physics Testing following a refueling outage. The Unit was at 0.4 percent power and performing individual CEA [Control Element Assembly] group worth testing. Specifically Regulating Group (RG) 2 was being inserted while RG 4 was being withdrawn. During the CEA manipulations, it was identified that there was a CEA deviation on RG 2 subgroup 17 that exceeded 6 inches from the remainder of the RG. RG 2 subgroup 18 was at 134 inches withdrawn and RG 2 subgroup 17 had two CEAs at 124 inches, one CEA at 122 inches and one CEA at 118 inches withdrawn. The CEA Malfunctions abnormal operating procedure 40AO-9ZZ11 was entered and a manual reactor trip was directed by the Control Room Supervisor. The reactor was tripped at 1925 hours.
"Unit 1 was at normal temperature and pressure prior to the trip. All CEAs inserted fully into the reactor core. This was an uncomplicated reactor trip. No ESF actuations occurred and none were required. Safety related buses remained energized during and following the reactor trip. The offsite power grid is stable. No significant LCOs have been entered as a result of this event. There was no loss of normal heat removal capabilities, or loss of any safety functions associated with this event. No major equipment was inoperable prior to the event that contributed to the event. The event did not result in any challenges to fission product barriers and there were no adverse safety consequences 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.
"The NRC Resident Inspector was informed of the Unit 1 reactor trip and this notification."
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 47473
Facility: FORT CALHOUN
Region: 4 State: NE
Unit: [1] [] []
RX Type: (1) CE
NRC Notified By: ROBERT KROS
HQ OPS Officer: MARK ABRAMOVITZ
Region: 4 State: NE
Unit: [1] [] []
RX Type: (1) CE
NRC Notified By: ROBERT KROS
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 11/23/2011
Notification Time: 01:43 [ET]
Event Date: 11/22/2011
Event Time: 17:00 [CST]
Last Update Date: 12/16/2011
Notification Time: 01:43 [ET]
Event Date: 11/22/2011
Event Time: 17:00 [CST]
Last Update Date: 12/16/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(B) - POT RHR INOP
10 CFR Section:
50.72(b)(3)(v)(B) - POT RHR INOP
Person (Organization):
RAY AZUA (R4DO)
RAY AZUA (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling Shutdown | 0 | Refueling Shutdown |
TEMPORARY LOSS OF SHUTDOWN COOLING
"During walkdown of scheduled work it was discovered that HCV-335 (Shutdown Cooling Heat Exchanger Inlet Header Isolation Valve) would not be able to be manually positioned open due to a missing idler gear key.
"Upon a loss of instrument air, HCV-335 would have failed closed, interrupting shutdown cooling flow with no ability to open HCV-335 manually.
"Alternate shutdown cooling pump and paths were available at the time of discovery. No loss of instrument air or interruption in shutdown cooling flow occurred while preparing to align alternate shutdown cooling. An 8 hour LCO under Technical Specification 2.8.1(3)2 was entered at 1700 CST. Alternate shutdown cooling was established on a containment spray pump as allowed by procedure. The 8 hour LCO was exited at 2306 CST. A replacement idler key has been fabricated for HCV-335."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION FROM ERICK MATZKE TO PETE SNYDER AT 1654 EST ON 12/16/11 * * *
"Additional analysis has determined that the shutdown cooling system was capable of performing its design safety functions during the time that the idler key was missing. Therefore this event is being retracted."
The licensee notified the NRC Resident Inspector.
Notified R4DO (Walker).
"During walkdown of scheduled work it was discovered that HCV-335 (Shutdown Cooling Heat Exchanger Inlet Header Isolation Valve) would not be able to be manually positioned open due to a missing idler gear key.
"Upon a loss of instrument air, HCV-335 would have failed closed, interrupting shutdown cooling flow with no ability to open HCV-335 manually.
"Alternate shutdown cooling pump and paths were available at the time of discovery. No loss of instrument air or interruption in shutdown cooling flow occurred while preparing to align alternate shutdown cooling. An 8 hour LCO under Technical Specification 2.8.1(3)2 was entered at 1700 CST. Alternate shutdown cooling was established on a containment spray pump as allowed by procedure. The 8 hour LCO was exited at 2306 CST. A replacement idler key has been fabricated for HCV-335."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION FROM ERICK MATZKE TO PETE SNYDER AT 1654 EST ON 12/16/11 * * *
"Additional analysis has determined that the shutdown cooling system was capable of performing its design safety functions during the time that the idler key was missing. Therefore this event is being retracted."
The licensee notified the NRC Resident Inspector.
Notified R4DO (Walker).