Morning Report for February 2, 1999
Headquarters Daily Report FEBRUARY 02, 1999 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III FEB. 02, 1999 Licensee/Facility: Notification: MR Number: 3-99-0004 Midwest Testing, Inc. Date: 02/01/99 Bridgeton,Missouri Telephone notification at 10:30 a.m Dockets: 03032036 License No: 24-24619-02 Subject: STOLEN CAMPBELL-PACIFIC NUCLEAR PORTABLE MOIST. DENS.GAUGE FOUND Discussion: The licensee reported to Region III that a Campbell-Pacific Nuclear (CPN) portable moisture density gauge, Model CPN-131, containing 10 millicuries (370 MBq) cesium-137 and 50 millicuries (1.85 GBq) americium-241 had been found by a West Virginia Highway Patrol State Trooper in a pile of garbage dumped in a ravine on the side of a highway near Charleston, West Virginia. In December, the licensee reported the device had been stolen from the licensee's locked construction trailer at a temporary job site during the evening of December 13, 1998, or early morning of December 14, 1998 (PNO-III-98-059). The gauge did not appear to be damaged and survey results did not indicate any unusual readings. The gauge was taken to the West Virginia Highway Department for storage and the licensee's radiation safety officer (RSO) was notified. The RSO plans to leak test the gauge and if results are negative, ship the gauge to the manufacturer for disposal. Regional Action: A follow-up 30-day written notification to the Region will be forwarded. Contact: Bob Hays (630)829-9819 _ REGION IV MORNING REPORT PAGE 2 FEBRUARY 2, 1999 Licensee/Facility: Notification: Southern California Edison & San MR Number: 4-99-0003 Diego Gas & Electric Co. Date: 02/01/99 San Onofre 2 RESIDENT INSPECTOR San Clemente,California Dockets: 50-361 PWR/CE Subject: UNUSUAL EVENT DECLARED FOR LOSS OF SHUTDOWN COOLING GREATER THAN 10 MINUTES (EVENT NUMBER: 35336) Discussion: On February 1, 1999, at 9:59 a.m. (PST), a loss of shutdown cooling occurred at San Onofre Unit 2. The facility was in Mode 6, with refueling in progress. At the start of the event, the Train A 4.1 kV Vital Bus 2A04 was being fed from the off-site transmission system via the unit auxiliary transformer. Train A Bus 2A04 was the protected supply to the operating shutdown cooling pump (used to cool the reactor coolant system) and to the operating containment spray pump (used to cool the spent fuel pool). The licensee was implementing a clearance order so that maintenance could be performed on the reserve auxiliary transformer, which was an alternate power supply for Train A 4.1 kV Bus 2A04. Breakers on the high and low side of the transformer had been opened and a ground buggy had been installed on the high side of the reserve transformer. The clearance called for racking out the Train A 4.16 kV breaker to the reserve auxiliary transformer. While attempting to rack out the breaker, electricians noted that the breaker was stuck and would not disengage. In the end, the breaker remained fully racked in. Discussions were held and the licensee incorrectly decided that discharging the closing springs would prevent the breaker from inadvertently closing, while attempting to rack the breaker out. Operators and electricians believed that pushing the button that discharges the closing springs would not cause the breaker to close, because they had pushed the button with the breaker racked out and the springs discharged without closing the breaker. However, the electricians pushed the button and the breaker closed. This resulted in the completion of the circuit between the offsite transmission system and the ground buggy installed on the high side of the reserve transformer, generating a fault. Preliminarily, the licensee believes that the fault was cleared by the loss of voltage relays on Bus 2A04. All of the supply breakers for Bus 2A04 tripped open, except the breaker to the reserve transformer. This breaker was in an off normal configuration (closed) with the control power fuses removed due to the actions of the electricians described above; therefore it could not open. As designed, the emergency diesel generator for Bus 2A04 started but did not tie to the bus because of a protective interlock that prevents more than one feed to the bus at a time. The operators secured the emergency diesel generator because other safety loads such as the emergency diesel generator auxiliaries were lost. REGION IV MORNING REPORT PAGE 3 FEBRUARY 2, 1999 MR Number: 4-99-0003 (cont.) The licensee evacuated the Unit 2 containment as required by the abnormal operating instruction for loss of shutdown cooling. Operators declared an Unusual Event at 10:09 a.m., and restored shutdown cooling at 10:25 a.m. Heatup of the reactor coolant system and the spent fuel pool was minimal during the period that the shutdown cooling and containment spray pumps were not operating (2 - 3 degrees F). The licensee exited the Unusual Event at 10:40 a.m. The licensee continues to investigate the exact cause for the loss of Vital Bus 2A04 and the failure of the emergency diesel generator to load onto the bus. Regional Action: NRC inspection of the event and its causes will continue. Contact: Linda J. Smith (817)860-8137 Jim Sloan (949)492-2641 _
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Page Last Reviewed/Updated Wednesday, March 24, 2021