United States Nuclear Regulatory Commission - Protecting People and the Environment

Event Notification Report for April 26, 2012

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
04/25/2012 - 04/26/2012

** EVENT NUMBERS **


47858 47862 47863 47864 47865

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Power Reactor Event Number: 47858
Facility: DIABLO CANYON
Region: 4 State: CA
Unit: [1] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: DAN STERMER
HQ OPS Officer: PETE SNYDER
Notification Date: 04/22/2012
Notification Time: 02:50 [ET]
Event Date: 04/21/2012
Event Time: 16:15 [PDT]
Last Update Date: 04/25/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
INFORMATION ONLY
Person (Organization):
NEIL OKEEFE (R4DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 82 Power Operation 20 Power Operation
2 N Y 100 Power Operation 100 Power Operation

Event Text

APPARENT PHASE IMBALANCE BETWEEN NORMAL AND ALTERNATE POWER CIRCUITS

"On April 21, 2012, at 1615 PDT, Diablo Canyon Power Plant (DCPP) operators identified that an attempted manual transfer of the Unit 1 AC power sources from the normal offsite circuit (500 kv) to the alternate offsite circuit (230 kv) failed.

"The attempted manual transfer of the offsite power source from the normal 500 kv to the alternate 230 kv was a planned activity to shut down Unit 1 for its 17th refueling outage. The failure to manually transfer was concluded to be caused by an indicated out of phase condition between the 500 kv and 230 kv system. DCPP control transfer systems prevent paralleling and transferring the power supplies from the normal to alternate offsite circuit with an out of phase condition. The offsite AC power sources remain capable of being manually transferred from the normal to the alternate source by way of transferring to diesels as an intermediate step.

"The 230 kv system ability to perform its accident mitigation safety function following a reactor trip or safety injection was not affected by the inability to perform a direct manual transfer from the 500 kv offsite power system.

"DCPP staff are currently troubleshooting the out of phase indication and will provide an update when the cause is concluded.

"The licensee notified the NRC Resident Inspector."

* * * UPDATE FROM MIKE QUITTER TO HOWIE CROUCH AT 2013 EDT ON 4/25/12 * * *

"This is an update to EN #47858 reported on April 22, 2012, where Pacific Gas & Electric Company (PG&E) reported that an attempt to manually transfer the DCPP Unit 1 AC power sources from the normal offsite circuit (500 kV) to the alternate required offsite circuit (230 kV) failed.

"PG&E determined that the out-of-phase condition between the 500kV system and the 230 kV system resulted from the offsite power system configurations and conditions existing at the time of the attempted transfer. PG&E established alternate operating guidance to allow operators to perform bus transfers between the 500kV source and the 230 kV source in the event that an out-of-phase condition exists when bus transfer is desired.

"PG&E personnel informed the NRC Resident Inspector."

Notified R4DO (Proulx).

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Power Reactor Event Number: 47862
Facility: FORT CALHOUN
Region: 4 State: NE
Unit: [1] [ ] [ ]
RX Type: (1) CE
NRC Notified By: ROBERT KROS
HQ OPS Officer: HOWIE CROUCH
Notification Date: 04/25/2012
Notification Time: 17:22 [ET]
Event Date: 04/25/2012
Event Time: 09:00 [CDT]
Last Update Date: 04/25/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
Person (Organization):
DAVID PROULX (R4DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N N 0 Cold Shutdown 0 Cold Shutdown

Event Text

UNANALYZED CONDITIONS RESULTING FROM A NON-CONSERVATIVE ERROR IN CALCULATIONS

"A non-conservative error was identified in the Proto-Flo input calculation FC06644 for LPSI (Low Pressure Safety Injection) flow post-RAS [recirculation actuation signal]. The calculation used an incorrect (non-conservative) input for LPSI pump performance. Also, the associated procedure (EOP/AOP Attachment 11) as written does not provide adequate direction during the Alternate Hot Leg Injection mode of operation.

"EOP/AOP Attachment 11 (Alternate Hot Leg Injection) used 140 psia as the entry point. The LPSI pumps may not be able to meet minimum flow requirements at this pressure, affecting core cooling and possibly resulting in pump damage. Also the EOP/AOP attachment directs the operator to verify that flow is approximately 400 gpm as indicated on FIC-326. If 400 gpm cannot be achieved the contingency is to open any LPSI loop injection isolation valve. This step would not depressurize the RCS low enough to allow the 400 gpm flow rate to be achieved which would cause insufficient flow.

"Therefore, it is reasonable to conclude that the referenced procedural guidance may not be able to complete the safety function of providing adequate core cooling during the Alternate Hot Leg Injection mode of operation under a worst case scenario.

"Therefore, this condition is an unanalyzed condition and reportable under 10CFR50.72(b)(3)(ii)(B)."

The licensee has notified the NRC Resident Inspector.

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Power Reactor Event Number: 47863
Facility: POINT BEACH
Region: 3 State: WI
Unit: [1] [2] [ ]
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: ALEX RIVAS
HQ OPS Officer: VINCE KLCO
Notification Date: 04/25/2012
Notification Time: 22:42 [ET]
Event Date: 04/25/2012
Event Time: 21:06 [CDT]
Last Update Date: 04/26/2012
Emergency Class: ALERT
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
Person (Organization):
JULIO LARA (R3DO)
JOHN LUBINSKI (NRR)
CYNTHIA PEDERSON (R3 R)
BRUCE BOGER (NRR)
JASON KOZAL (IRD)
ELLIOT BRENNER (PAO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 100 Power Operation
2 N Y 100 Power Operation 100 Power Operation

Event Text

ALERT DECLARED DUE TO TOXIC GAS BUILD UP FOLLOWING AN EMERGENCY DIESEL GENERATOR TEST RUN

On April 25, 2012 at 2106 CDT, Point Beach Nuclear Plant declared an Alert under EAL HA3.1 due to toxic gas in a vital area. During a maintenance run on the plant's emergency diesel generator, diesel exhaust caused the concentration of carbon monoxide in an adjacent vital area room (Plant Instrument Air Compressor Room) to exceed OSHA IDLH (Immediately Dangerous to Life and Health) levels. The diesel was immediately secured and the room was ventilated. There were no personnel injuries and no public health and safety issues associated with this event.

The licensee notified the NRC Resident Inspector.

Notified DHS SWO, FEMA, USDA, DOE, DHS NICC, HHS AND EPA.

* * * UPDATE FROM JOHN RODGERS TO JOHN SHOEMAKER AT 0022 EDT ON 04/26/12 * * *

The Alert at Point Beach was terminated at 2314 CDT on 04/25/12.

The licensee notified the NRC Resident Inspector. Notified R3DO (Lara), NRR EO (Lubinski), IRD (Scott via email only).

Notified DHS SWO, FEMA, USDA, DOE, DHS NICC, HHS, EPA, and Nuclear SSA (email only).

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Power Reactor Event Number: 47864
Facility: COOK
Region: 3 State: MI
Unit: [ ] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BUD HINCKLEY
HQ OPS Officer: JOHN SHOEMAKER
Notification Date: 04/26/2012
Notification Time: 01:21 [ET]
Event Date: 04/25/2012
Event Time: 22:46 [EDT]
Last Update Date: 04/26/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
Person (Organization):
JULIO LARA (R3DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N N 0 Cold Shutdown 0 Cold Shutdown

Event Text

NOTIFICATION TO OFFSITE AGENCIES DUE TO OIL SPILL

"At 2246 EDT on April 25, 2012, D.C. Cook notified the State of Michigan and local authorities of an oil spill from the Unit 2 [Main Generator] Seal Oil system at 2110 EDT which resulted in a portion of this oil entering the absorption pond, which is in the owner controlled area. An oil sheen is present on the absorption pond which has a surface area of approximately 2 acres (87,000 square feet) and it is estimated that five to ten gallons of oil are on the absorption pond.

"The NRC Resident Inspector was notified."

The licensee has contained the oil leak and clean up efforts are ongoing.

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Power Reactor Event Number: 47865
Facility: DIABLO CANYON
Region: 4 State: CA
Unit: [ ] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: DAVE GOUVEIA
HQ OPS Officer: CHARLES TEAL
Notification Date: 04/26/2012
Notification Time: 04:20 [ET]
Event Date: 04/25/2012
Event Time: 22:27 [PDT]
Last Update Date: 04/26/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
Person (Organization):
DAVID PROULX (R4DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 25 Power Operation 0 Hot Standby

Event Text

PRESS RELEASE ISSUED FOR SHUTDOWN OF UNIT 2 DUE TO SALP INFLUX

"On April 25, 2012, at 2227 PDT, Diablo Canyon Power Plant (DCPP) U2 was manually taken offline and the reactor shut down due to an influx of sea salp - a small, jellyfish-like organism - in the intake structure. Operators manually started the auxiliary feedwater pumps in accordance with the plant operating procedures.

"PG&E will not restart Unit 2 until conditions improve at the intake structure. As previously announced, Unit 1 was safely shut down for a planned refueling and maintenance outage.

"All systems operated as designed and no unexpected equipment performance issues were noted.

"The licensee notified the NRC Resident Inspector."

The licensee plans on issuing a press release.

Page Last Reviewed/Updated Thursday, April 26, 2012
Thursday, April 26, 2012