PNO-I-08-003, A: Limerick, Update - Shutdown Exceeding 72 Hrs
| ML080460528 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/15/2008 |
| From: | Paul Krohn Reactor Projects Region 1 Branch 4 |
| To: | |
| KROHN, PG | |
| References | |
| PNO-I-08-003A | |
| Download: ML080460528 (1) | |
Date: February 15, 2008 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-I-08-003A 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:
UPDATE - 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 increased from 0.01 to 1.2 gallons per minute (gpm). This coincided with intermittent seal leakage high flow alarms associated with the pump. Unidentified leakage continued to increase to 2.7 gpm at 12:15 a.m. on February 10. 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 Following the shutdown, the licensee determined that the cause of the unidentified leakage was increased back pressure on the recirculation pump seal leak-off line. This caused seal leak-off flow to be diverted to containment. Two maintenance valves designed to drain the recirculation pump casing leaked-by and caused the increased back pressure on the recirculation seal.
Following repairs associated with the 2A recirculation pump, Limerick Unit 2 returned to power operations on February 14, 2008. The licensee commenced reactor startup and achieved criticality on February 13, at 3:09 a.m. The main turbine generator was synchronized to the electrical grid at 1:48 a.m. on February 14. The resident inspectors reviewed or observed portions of the reactor startup, synchronization of the generator to the grid, and initial power ascension.
This information is current as of 3:00 p.m. EST on February 14, 2008 when reactor power was approximately 55 percent.
The Region I Public Affairs Office will respond to media inquires. The State of Pennsylvania has been informed of this update.
ADAMS ACCESSION NUMBER: ML080460528 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 ML080460528 SUNSI Review Complete: PGK (Reviewers Initials)
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- Original initials and concurrence obtained on copy dated 2/14/08 OFFICE RI/DRP RI/ORA RI/DRP RI/ORA RI/ORA NAME PKrohn/ DScrenci/** DLew/JC for MMcLaughlin ** SCollins/MLD for DATE 02/ 15 /08 02/14 /08 02/15 /08 2/14/08 02/15 /08 OFFICIAL RECORD COPY