ML080420618
| ML080420618 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/11/2008 |
| From: | Krohn P G Reactor Projects Region 1 Branch 4 |
| To: | |
| KROHN, PG | |
| References | |
| PNO-I-08-003 | |
| Download: ML080420618 (2) | |
Text
Date: February 11, 2008 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE
- PNO-I-08-003 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, King of Prussia, PA, staff on this date.
Facility License Emergency Classification Exelon ____Notification of Unusual Event Limerick Generating Station, Unit 2 _____Alert Pottstown, PA _____Site Area Emergency Docket: 050-00353 _____General Emergency License: NPF-85 __X___Not Applicable
SUBJECT:
SHUTDOWN EXCEEDING 72 HOURS
DESCRIPTION:
On February 10, 2008, Limerick was shut down to repair the 2A recirculation pump seal. On February 9 at 6:12 p.m., unidentified leakage in the drywell increase from 0.01 to 1.2 gallons per minute (gpm). This coincided with intermittent seal leakage high flow alarms associated with the pump. Due to unidentified leakage increasing by more than 2.0 gpm over a 24-hour period, the plant entered a technical specification at 9:52 p.m. requiring the company to identify the source of the leakage within four hours. Unidentified leakage peaked at 2.7 gpm at 12:15 a.m.
on February 10.
Operators began reducing power on Unit 2 early Sunday morning to enter single-loop operation on the 2B recirculation pump and allow securing of the 2A recirculation pump. The 2A recirculation pump was secured and isolated by 1:25 a.m. Sunday, and drywell unidentified leakage subsequently trended downward, indicating that the leak had been associated with the 2A recirculation pump. Once identifying the source of the leak, the company then elected to shut down the unit to repair the pump seal.
The NRC senior resident inspector responded to the site to monitor the licensee's response to the event and independently verified plant conditions. The Region I staff continues to follow licensee activities.
The Commonwealth of Pennsylvania has been informed. Region I Public Affairs is prepared to respond to media inquiries.
The information presented herein has been discussed with Exelon, and is current as of 1:30 pm, February 11, 2008. Region I plans to provide an update to this Preliminary Notification following plant restart.
ADAMS ACCESSION NUMBER:
ML080420618 CONTACTS: Paul G. Krohn
610-337-5120 pgk1@nrc.gov
DISTRIBUTION: (PN Recipient List)
OWFN TWFN Chairman Klein Comm. Lyons NMSS Comm. Jazcko ACRS OIP NSIR OCA OIG OGC EDO OE NRR SECY Regional Offices BY FAX: Dot: Trans INPO NSAC RI Resident Office Licensee: Exelon
Limerick Generating Station
SUNSI Review Complete: PGK (Reviewer's Initials)
DOCUMENT NAME: G:\DRP\BRANCH4\PNO-I-08-003.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 attach ment/enclosure " N" = No copy OFFICE RI/DRP RI/ORA RI/ORA RI/ORA RI/DRP NAME PKrohn/PGK RBarkley/RB MMcLaughlin/MM DScrenci/DS DLew/DCL DATE 02/ 11 /08 02/11 /08 02/ 11/08 02/ 11/08 02/ 11 /08 OFFICIAL RECORD COPY