PNO-III-06-018, Fermi 2 Reactor Shutdown and Unusual Event
| ML062140698 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 08/02/2006 |
| From: | Lerch R, Christine Lipa Division of Nuclear Materials Safety III |
| To: | Detroit Edison |
| References | |
| PNO-III-06-018 | |
| Download: ML062140698 (2) | |
August 2, 2006 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-III-06-018 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 III staff on this date.
Facility Fermi 2 Detroit Edison Co.
Newport MI Docket: 50-341 License: DPR-63 Licensee Emergency Classification X Notification of Unusual Event Alert Site Area Emergency General Emergency Not Applicable
SUBJECT:
FERMI 2 REACTOR SHUTDOWN AND UNUSUAL EVENT DESCRIPTION:
At 3:50 p.m. EDT on July 29, 2006, the reactor shut down automatically on reactor low water level when electrical power was interrupted to Division 1 systems. This occurred during maintenance work on a transformer.
All safety systems functioned as designed during the reactor shutdown. The emergency diesel generators started and supplied power to those systems affected by the loss of electrical power.
Following investigation and troubleshooting activities, the plant was restarted at 4:21 a.m. on July 31, 2006.
When the plant was at 6 percent power, a carbon dioxide fire protection system for the cable tray room actuated. The utility declared an Unusual Event at 1:44 p.m. on July 31, 2006, because of the release of the carbon dioxide into the plant. As a precaution, personnel were evacuated from the auxiliary building and the reactor building. Area surveys showed no evidence of fire.
The reactor was held at the low power level while the plant staff investigated the circumstances surrounding the fire protection system actuation.
The utility determined that high humidity affected the fire detection system sensors, causing the fire protection system actuation. The sensors are being replaced, and, until the fire detection system is fully operable, the utility is taking compensatory fire protection actions.
Following completion of the utility review, the Unusual Event classification was terminated at 9:33 p.m. on July 31,2006, and the reactor power increase process was resumed. The plant was synchronized to the grid at 11:07 a.m. on August 1, 2006.
The State of Michigan has been informed of the Unusual Event. Region III (Chicago) has responded to area news media inquiries on the reactor shutdown and Unusual Event.
This information is current as of 11 a.m. on August 2, 2006.
The information in this preliminary notification has been reviewed with license management.
CONTACTS:
Robert Lerch Christine Lipa 630/829-9759 630/829-9619