NRC SENDS AUGMENTED INSPECTION TEAM TO PALO VERDE NUCLEAR GENERATING STATION
NRC SENDS AUGMENTED INSPECTION TEAM TO
PALO VERDE NUCLEAR GENERATING STATION
WALNUT CREEK, Calif., Nov. 15 /PRNewswire/ -- Nuclear Regulatory Commission Region V Deputy Regional Administrator Bobby H. Faulkenberry has established an Augmented Inspection Team (AIT) in response to an event which occurred today at the Palo Verde Nuclear Generating Station, Unit 3, located 65 miles west of Phoenix, Ariz. The four-member team will be led by Lewis F. Miller, Section Chief, Operations Section, of the NRC Region V office in Walnut Creek.
The team will independently establish the circumstances and facts of the event, which was initiated when a mobile crane boom contacted an electrical line supplying power to Unit 3, causing a fault. Unit 3 was in hot shutdown at the time to repair a transformer which was damaged in an electrical event on Thursday, Nov. 14.
When the fault occurred, at about 9 a.m. MST this morning, an apparent miscommunication caused Unit 3 operators to disconnect the non-faulted remaining connection to the electrical grid. The faulted line continued to supply power to Unit 3. Subsequent communication apparently clarified the error, and operators re-established power supply from the non-faulted line and disconnected the faulted line.
The disconnection of power supply lines caused the Unit 3 reactor coolant pumps to lose power. The shut down reactor was cooled by the natural circulation of water for about 28 minutes, until operators restarted a reactor coolant pump. Cooling by natural circulation was successfully demonstrated for each of the Palo Verde units prior to licensing.
There were no injuries and no releases of radioactive materials involved in the event.
During the fault, asphalt below the crane began to smoke. Operators declared an Unusual Event at 9:29 a.m. MST based on a fire within the plant protected area lasting greater than ten minutes (the smoking asphalt), and secured from the Unusual Event at 10:02 a.m. MST when the asphalt was extinguished.
The team will begin its onsite activities Saturday, Nov. 16, and initially expects to be onsite about three days. A report documenting the AIT activities and findings is expected in about 30 days.
/CONTACT: Greg Cook of U.S. NRC, Office: 510-975-0346 , or
Home: 707-644-2428/ CO: U.S. Nuclear Regulatory Commission ST: Arizona IN: SU: RM -- SF009 -- 1829 11/15/91 20:43 EST