ML093550301
| ML093550301 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/21/2009 |
| From: | Jackson D E NRC/RGN-I/DRP/PB5 |
| To: | |
| Jackson, D E RI/DRP/PB5/610-337-5306 | |
| References | |
| FOIA/PA-2011-0115 PNO-I-09-007 | |
| Download: ML093550301 (2) | |
Text
DCS No.: 0500042312212009 Date: December 21, 2009
PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-I-09-007
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 I staff on this date.
Facility Dominion Nuclear Connecticut Millstone Unit 3 Waterford, CT Docket: 50-423 Licensee Emergency Classification Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable
SUBJECT:
MILLSTONE UNIT 3 REACTOR TRIP AND SHUTDOWN GREATER THAN 72 HOURS
On December 19, 2009, at 10:53 p.m., Millstone Unit 3 experienced an automatic reactor trip due to an electrical fault on the main generator output circuit breaker. All plant safety systems responded as expected. The plant was safely placed in hot standby.
The main generator output circuit breaker experienced an electrical fault. A number of protective relays actuated as designed and opened the main generator output breakers, tripping the turbine and subsequently, shutting down the reactor. The operators stabilized the plant in hot standby and decay heat removal was accomplished by operating a combination of both the atmospheric steam relief valves and ultimately the main condenser steam dump valves.
The electrical fault caused the loss of one offsite power source to Unit 3. The plant responded as designed and transferred all applicable electrical busses to the alternate offsite power source. Offsite power was maintained to all electrical busses throughout the duration of the transient. Both emergency diesel generators remain operable and the station blackout diesel generator is available.
In accordance with the plant's technical specifications, the licensee is placing the reactor in cold shutdown due to one offsite power source being declared inoperable as a result of the electrical fault. The licensee is presently evaluating the cause and extent of condition of the electrical fault and developing a schedule for repairs.
The NRC resident inspector responded to the site upon initial notification of the issue.
State and local officials have been informed.
The NRC Region I Public Affairs Office is responding to media inquiries.
The information presented herein has been discussed with Dominion and is current as of December 21, 2009, at 2:00 p.m.
NRC Region I will update this Preliminary Notification after plant restart.
ADAMS Accession Number: ML093550301
CONTACT: Donald Jackson (610) 337-5306 DISTRIBUTION: (by email: Rl-DL-PN; PN_Distribution)
Chairman Jazcko Comm. Klein Comm. Svinicki OIP OCA OGC OPA EDO OE NRR SECY IRO NMSS ACRS OIG RES NSIR NRO PDR RSLO Regional Offices
By Fax:
DOT:Trans INPO NSAC RI Resident Office Licensee: Dominion Nuclear Connecticut (Millstone 3)
ADAMS Accession Number: ML093550301
SUNSI Review Complete: DEJ ___ (Reviewer's Initials)
DOCUMENT NAME: G:\DRP\PNs\PNO-I-09-007 - MS3 Rx Trip.doc After declaring this document "An Official Agency Record" it will be released to the Public.
To receive a copy of this document, indicate in the box:
" C" = Copy without attachment/enclosure "
E" = Copy with attachment/enclosure
" N" = No copy OFFICE RI/DRP RI/ORA RI/PAO RI/DRP NAME DJackson/DEJ RBarkley/ RB DScrenci/ DS DLew/ DCL DATE 12/21/09 12/21/09 12/21/09 12/21/09 OFFICIAL RECORD COPY Region I Form 83 (Rev. July 2, 2003)