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Event Notification Report for February 4, 2008

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
02/01/2008 - 02/04/2008

** EVENT NUMBERS **


43949 43951 43952 43953 43956

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Power Reactor Event Number: 43949
Facility: LIMERICK
Region: 1 State: PA
Unit: [ ] [2] [ ]
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: MARK CRIM
HQ OPS Officer: JOE O'HARA
Notification Date: 02/01/2008
Notification Time: 05:45 [ET]
Event Date: 02/01/2008
Event Time: 04:45 [EST]
Last Update Date: 02/01/2008
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
Person (Organization):
NEIL PERRY (R1)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 A/R Y 100 Power Operation 0 Hot Shutdown

Event Text

AUTOMATIC SCRAM AS A RESULT OF TURBINE TRIP

"Unit 2 automatically scrammed [at] 0445 as a result of an RPS actuation due to a turbine trip. All rods inserted. The plant is stable. No ECCS or SRV actuation occurred. This report is made pursuant to 50.72(B)(iv)(B). An investigation into the cause is currently in progress. "

Primary plant pressure is 900 psig. with the decay heat path to the condenser via turbine bypass valves. All safety related systems are operable, and the licensee is investigating a potential issue with the EHC system.

The NRC Resident Inspector has been informed. The Commonwealth of Pennsylvania and local government agency will be informed. The licensee will issue a press release.

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Power Reactor Event Number: 43951
Facility: MILLSTONE
Region: 1 State: CT
Unit: [1] [ ] [ ]
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: LENNY MAUSPELLER
HQ OPS Officer: BILL HUFFMAN
Notification Date: 02/01/2008
Notification Time: 13:47 [ET]
Event Date: 02/01/2008
Event Time: 10:24 [EST]
Last Update Date: 02/01/2008
Emergency Class: NON EMERGENCY
10 CFR Section:
OTHER UNSPEC REQMNT
Person (Organization):
HAROLD GRAY (R1)
TERRENCE REIS (FSME)

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

Event Text

LOSS OF SPENT FUEL POOL COOLING

Millstone Unit 1 is in a decommissioning status but still maintains spent fuel in the spent fuel pool. On January 30, 2008, the normal power to the Unit 1 spent fuel pool was lost due to a fault (overcurrent trip) in the "Trayer Switch" (an auto disconnect switch) in the electrical supply line to the spent fuel pool cooling bus. A backup diesel generator was started and was being used to power the spent fuel pool cooling system until the "Trayer Switch" was repaired. At approximately 0840 EST today (2/01/08), alarms were received indicating low decay heat pump low flow and low spent fuel pool cooling pump low flow and discharge pressure. Investigation revealed that the backup diesel generator was operating at a frequency of 57.5 Hz rather than the normal 60 Hz. The technical staff was unable to get the diesel generator to maintain the normal 60 Hz output frequency. The licensee elected to secure the spent fuel pool cooling system pumps at 1024 EST based on concerns that the pumps could be damaged if operated at under frequency for an extended period of time.

Licensee technicians are currently engaged in repairing the diesel generator frequency controls and estimate that it could be returned to service this afternoon. The licensee has also ordered a temporary skid mounted diesel generator which should also arrive this afternoon. The repairs to the normal power source are not anticipated to be completed until Monday (2/04/08).

The spent fuel pool temperature has increased 1 degree to 86 F in approximately 4 hours. The tech spec limit on spent fuel pool temperature is 150 F. The licensee states that other unit electrical systems powered off the diesel, such as lighting and rad monitors, continue to operate normally at the reduced output frequency of the diesel. One security tower has been slightly impacted but appropriate compensatory measures were implemented.

A Millstone Unit 2/3 Resident Inspector has been notified. The licensee has attempted to contact the Regional Inspector.

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Power Reactor Event Number: 43952
Facility: RIVER BEND
Region: 4 State: LA
Unit: [1] [ ] [ ]
RX Type: [1] GE-6
NRC Notified By: TIM SCHENK
HQ OPS Officer: JEFF ROTTON
Notification Date: 02/01/2008
Notification Time: 14:47 [ET]
Event Date: 02/01/2008
Event Time: 13:45 [CST]
Last Update Date: 02/01/2008
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
MICHAEL HAY (R4)

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

Event Text

SCHEDULED LOSS OF ALL MAIN CONTROL ROOM ANNUNCIATORS TO SUPPORT PLANT MAINTENANCE

"At 01:45 PM CST on 2/1/2008, the Main Control Room annunciator system has been removed from service to support maintenance at River Bend Station. The duration of the work is expected to be completed in less than one (1) hour.

"During this time, other Main Control Room indications and alternate methods will be available to implement the Emergency Plan. Since the Main Control Room annunciator system will be unavailable, this is considered a Loss of Emergency Assessment Capability and reportable under 10CFR50.72(b)(3)(xiii).

"A follow-up notification will be made to the NRC after the Main Control Room annunciator system is returned to service.

"The licensee notified the NRC Resident Inspector."

The reactor is defueled and there are no major evolutions scheduled to occur during this period.

* * * UPDATE PROVIDED BY TIM SCHENK TO JEFF ROTTON AT 1530 EST ON 02/01/08 * * *

"Main Control Room annunciator system has been restored to service at 1528 EST."

The licensee notified the NRC Resident Inspector. Notified the R4DO (Hay).

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Fuel Cycle Facility Event Number: 43953
Facility: PADUCAH GASEOUS DIFFUSION PLANT
RX Type: URANIUM ENRICHMENT FACILITY
Comments: 2 DEMOCRACY CENTER
                   6903 ROCKLEDGE DRIVE
                   BETHESDA, MD 20817 (301)564-3200
Region: 2
City: PADUCAH State: KY
County: McCRACKEN
License #: GDP-1
Agreement: Y
Docket: 0707001
NRC Notified By: M.C. PITMAN
HQ OPS Officer: BILL HUFFMAN
Notification Date: 02/01/2008
Notification Time: 14:48 [ET]
Event Date: 01/31/2008
Event Time: 14:06 [CST]
Last Update Date: 02/01/2008
Emergency Class: NON EMERGENCY
10 CFR Section:
76.120(c)(2) - SAFETY EQUIPMENT FAILURE
Person (Organization):
BRIAN BONSER (R2)
NADER MAMISH (NMSS)

Event Text

24 HOUR REPORT OF RELEASE DETECTION SYSTEM FAILURE

"At 1406 CST, on 01-31-08 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-333 Unit 3 Cell 5 UF6 Release Detection (PGLD) System. Operators responded to the panel and verified the alarm was false but when they attempted to test the system it failed. Preliminary troubleshooting indicates that the cause of the alarm may have been a momentary loss of power. This PGLD System contains detectors that cover the C-333 Unit 3 Cell 5 cell housing roof and inter-cell housing. At the time of this alarm, C-333 Unit 3 Cell 5 was operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell housing roof and inter-cell housing are operable during steady state operations above atmospheric pressure. With the Unit 3 Cell 5 PGLD system inoperable, none of the required 3 heads in the cell housing roof and inter-cell housing were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.B.1 was entered and a continuous smoke watch was put in place within one hour. An investigation is ongoing to attempt to conclusively and accurately determine the cause of the alarm.

"This event is being reported as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function.

"The NRC Senior Resident Inspector has been notified of this event."

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Power Reactor Event Number: 43956
Facility: COOK
Region: 3 State: MI
Unit: [1] [ ] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: RICH KRESS
HQ OPS Officer: JASON KOZAL
Notification Date: 02/02/2008
Notification Time: 07:44 [ET]
Event Date: 02/02/2008
Event Time: 05:30 [EST]
Last Update Date: 02/02/2008
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
Person (Organization):
CHRISTINE LIPA (R3)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 M/R Y 93 Power Operation 0 Hot Standby

Event Text

MANUAL REACTOR TRIP DUE TO HIGH TURBINE VIBRATIONS

"The DC Cook Unit 1 Reactor was manually tripped from 93% power due to high vibrations on main turbine bearings #5 and 6.

"This event is reportable under 10CFR50.72(b)(2)(iv)(B), RPS actuation, as a four (4) hour report and under 10CFR50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report.

"Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 1 remains stable in Mode 3 while conducting the post Trip Review. No radioactive release is in progress as a result of this event.

"The DC Cook Resident NRC Inspector was notified 02/02/08 at approximately 0535 EST.

"The electrical grid is stable and Unit 1 is being supplied by offsite power. Unit 2 is not affected. All control rods fully inserted. Decay heat is being removed via steam dumps to the main condenser."

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