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Event Notification Report for September 28, 2007

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
09/27/2007 - 09/28/2007

** EVENT NUMBERS **


43668 43670

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Power Reactor Event Number: 43668
Facility: RIVER BEND
Region: 4 State: LA
Unit: [1] [ ] [ ]
RX Type: [1] GE-6
NRC Notified By: GARY HUSTON
HQ OPS Officer: JOE O'HARA
Notification Date: 09/27/2007
Notification Time: 03:48 [ET]
Event Date: 09/26/2007
Event Time: 22:44 [CDT]
Last Update Date: 09/27/2007
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
Person (Organization):
CLAUDE JOHNSON (R4)

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

Event Text

AUTOMATIC REACTOR SCRAM DURING THE PERFORMANCE OF APRM SURVEILLANCE TESTING

"At approximately 2244 on September 26, 2007 an unplanned reactor scram occurred. An Average Power Range Monitor (APRM) surveillance was being performed at the time. This surveillance should not have caused a full scram and the cause of the scram is under investigation. The plant responded to the scram as expected, all control rods fully inserted, and there is no need for emergency injection system operation. Critical parameters are being maintained within prescribed bands and the plant has been stabilized. A level 3 signal was received during this scram which would have caused an isolation but all affected valves were already in the closed position.

"This event is being reported in accordance with 10CFR50.72(b)(2)(iv)(B) as an event that results in activation of the reactor protection system with the reactor critical."

All emergency systems are available and in standby mode.

The licensee notified the NRC Resident Inspector.

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Fuel Cycle Facility Event Number: 43670
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. PITTMAN
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 09/27/2007
Notification Time: 16:02 [ET]
Event Date: 09/27/2007
Event Time: 00:12 [CDT]
Last Update Date: 09/27/2007
Emergency Class: NON EMERGENCY
10 CFR Section:
76.120(c)(2) - SAFETY EQUIPMENT FAILURE
Person (Organization):
MALCOLM WIDMANN (R2)
ROBERT PIERSON (FSME)

Event Text

TEMPORARY LOSS OF SMOKE DETECTOR FUNCTION

"At 0012 CDST, on 9-27-07 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-333 Unit 6 Cell 4 UF6 Release Detection (PGLD) System. Operators responded and found that the READY and MANUAL lights for this system were not illuminated. This PGLD System contains detectors that cover C-333 Unit 6 Cell 4 and Section 2 of the cell bypass piping. At the time of this alarm, some areas of Section 2 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 6 Cell 4 PGLD system inoperable, only 2 of the required 3 heads in Section 2 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.C.1 was entered and a continuous smoke watch was put in place within one hour. Maintenance investigated and determined that two detector heads had shorted to ground which caused this alarm. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. The shorted heads were replaced and the GLD System was declared operable at 0350 hours on 9-27-07 following repairs and testing. This event is reportable as a 24 hour event in accordance with 10CFR 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 o demand, and c.) no redundant equipment is available and operable to perform the required safety function."

The licensee notified the NRC Resident Inspector.

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Thursday, March 29, 2012