PNO-II-12-001, Notification of Unusual Event Due to Loss of Offsite Power (Catawba)
| ML120960145 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/05/2012 |
| From: | William Jones Division Reactor Projects II |
| To: | |
| William Jones | |
| References | |
| PNO-II-12-001 | |
| Download: ML120960145 (1) | |
April 5, 2012 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-12-001 This preliminary notification constitutes EARLY notice of events of possible safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by Region II staff (Atlanta, Georgia) on this date.
Facility:
Licensee Emergency Classification:
Catawba Nuclear Station Notification of Unusual Event Units 1 and 2, York, SC Alert Site Area Emergency Docket Numbers: 50-413 and 50-414 License Numbers: NPF-35 and NPF-52 General Emergency Not Applicable
SUBJECT:
NOTIFICATION OF UNUSUAL EVENT DUE TO LOSS OF OFFSITE POWER At 8:54 P.M. EDT, on April 4, 2012, NRC entered the Monitoring Mode following the Catawba Nuclear Station Units 1 and 2 declaring a Notification of Unusual Event at 8:12 P.M. Prior to the event, Unit 1 was operating at 100% power and Unit 2 was in Mode 5, cold shutdown for a refueling outage. A loss of offsite power (LOSP) resulted in a reactor trip of Unit 1 and temporary loss of shutdown cooling for Unit 2. The two emergency diesel generators for each unit started and powered the emergency buses. The reactor trip of Unit 1 was uncomplicated. Decay heat was removed through the steam generator power operated relief valves and auxiliary feedwater (AFW) was supplied by the AFW pumps.
The licensee indicated that offsite AC power was available upstream of the switchyard tie breakers and they are investigating the actual cause of the LOSP. The licensee reported no precursor indications of an imminent LOSP, nor were there licensee evolutions, or adverse weather conditions in the area that would have caused the event. The licensee stated that a security review did not reveal any unusual conditions, nor was any security equipment affected by the LOSP.
The licensee notified the states of North Carolina and South Carolina and the local counties of the NOUE. The licensee also staffed both the Technical Support Center and the Emergency Operations Facility.
Region II received initial telephone notification of this occurrence from the licensee. NRC inspectors responded to the site to monitor the licensees activities. The licensee exited the NOUE at 1:37 A.M., April 5, 2012, once offsite power was restored to one safety bus on each unit. The NRC exited the Monitoring Mode at 1:54 A.M. The information presented herein has been discussed with the licensee and State officials and is current as of 2:00 A.M.
CONTACT:
William Jones 404 997-4501