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Event Notification Report for May 26, 2010

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
05/25/2010 - 05/26/2010

** EVENT NUMBERS **


45942 45952

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General Information or Other Event Number: 45942
Rep Org: TEXAS DEPARTMENT OF HEALTH
Licensee: DIAMOND SHAMROCK REFINING COMPANY
Region: 4
City: THREE RIVERS State: TX
County:
License #: 03699
Agreement: Y
Docket:
NRC Notified By: ART TUCKER
HQ OPS Officer: JOE O'HARA
Notification Date: 05/21/2010
Notification Time: 12:50 [ET]
Event Date: 05/21/2010
Event Time: [CDT]
Last Update Date: 05/21/2010
Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
Person (Organization):
GREG PICK (R4DO)
ANGELA MCINTOSH (FSME)

Event Text

AGREEMENT STATE REPORT - STUCK OPEN SHUTTER ON RONAN GAUGE

The following report was received from the State of Texas via e-mail:

"On May 21, 2010, the Agency [State of Texas] was notified by the licensee that while conducting a routine inspection of a Ronan Engineering model SA1-F37 nuclear gauge, the shutter failed to close. The gauge was installed in 1991 and contained a 20 millicurie Cesium (Cs) - 137 Source. The licensee conducted a radiation survey in the area of the gauge and found the dose rates to be normal. Open is the normal operating condition for the gauge therefore there is no additional exposure risk to their workers. The vessel the gauge is associated with has been posted to warn workers hat the shutter is not functioning properly. The licensee has contacted the manufacturer to schedule the repair. The licensee stated that the repair should be completed within the next 60 days."

Texas Incident Number I-8746

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Power Reactor Event Number: 45952
Facility: PRAIRIE ISLAND
Region: 3 State: MN
Unit: [ ] [2] [ ]
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: TERRY BACON
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 05/25/2010
Notification Time: 06:50 [ET]
Event Date: 05/25/2010
Event Time: 03:14 [CDT]
Last Update Date: 05/25/2010
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):
KENNETH RIEMER (R3DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 A/R Y 32 Power Operation 0 Hot Standby

Event Text

AUTOMATIC REACTOR TRIP DUE TO TURBINE TRIP

"During a normal plant power increase following a refueling outage on Unit 2, a reactor trip occurred at approximately 32% power. This reactor trip was the result of a turbine trip. The cause of the turbine trip is unknown at this time, however, a lock out trip occurred on the only running main feed water pump (21 main feedwater pump) at the time of the turbine and reactor trip. An investigation is ongoing.

"The reactor trip first actuated indication was a turbine trip. An automatic start of both Auxiliary Feed Water pumps occurred following the trip.

"The operating crew responded to the reactor trip utilizing emergency operating procedures for reactor trip and reactor trip recovery and transitioned into a normal shutdown procedure.

"All rods inserted as expected and all other systems operated as expected with the exception of a positive displacement charging pump that lifted a relief that failed to reclose."

The positive displacement pump relief valve stuck open and the pump was shut down which isolated the relief valve. Decay heat was initially being removed to the main condenser however, steam leak by was causing a plant cooldown therefore the Main Steam Isolation Valves were shut. Decay heat is being removed using the steam generator atmospheric relief valves. There is no known primary to secondary leakage. The plant is in its normal shutdown electrical lineup.

The licensee notified the NRC Resident Inspector.

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Thursday, March 29, 2012