ML111770003
| ML111770003 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 06/26/2011 |
| From: | NRC Region 4 |
| To: | |
| References | |
| PNO-IV-11-003B | |
| Download: ML111770003 (1) | |
Text
June 26, 2011 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-11-003B 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 the Region IV, Arlington, Texas, staff on this date.
Facility Fort Calhoun Station
Docket: 50-285 License No. DPR-40 Licensee Emergency Classification X Notification of Unusual Event Alert Site Area Emergency General Emergency Not Applicable
SUBJECT:
(UPDATE) Fort Calhoun Station Declaration of a Notification of Unusual Event Due to High River Level DESCRIPTION: This Preliminary Notification (PN) updates information discussed in PNO-IV-003 and PNO-IV-003A. On June 26, 2011, at approximately 1:25 a.m., the water berm that had been providing supplemental floodwater protection to Fort Calhoun Station failed as a result of site activities. As a result, floodwaters have reached an elevation of 1006 feet 4 inches (mean sea level, MSL) around the auxiliary and containment buildings. Those buildings are protected by design to a floodwater elevation of 1014 feet MSL.
The failure of the water berm allowed floodwaters to surround the main electrical transformers, which prompted the licensee to take the precautionary measure of transferring from offsite power to onsite emergency diesel generators (EDGs). Reactor shutdown cooling and spent fuel pool cooling remain unaffected. The licensee is developing plans to restore the site to offsite power. In response to this event, the NRC entered the Monitoring mode of Incident Response at 1:53 a.m. (CDT) and staffed the Region IV Incident Response Center.
Fort Calhoun Station remains in the Notification of Unusual Event (NOUE) that was declared on June 6, 2011.
Region IV received notification of this occurrence by phone from the augmented resident inspector staff at the site.
The States of Nebraska and Iowa have been notified.
The information presented herein has been discussed with the licensee and is current as of 10:00 a.m., June 26, 2011.
ADAMS ACCESSION NUMBER: ML111770003 CONTACTS: Ray Azua, at (817) 319-4376