ML090490527

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PNO-III-09-001, Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seals
ML090490527
Person / Time
Site: Palisades Entergy icon.png
Issue date: 02/18/2009
From:
NRC/RGN-III
To:
References
PNO-III-09-001
Download: ML090490527 (1)


Text

PRELIMINARY NOTIFICATION- REGION III February 18, 2009 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-III-09-001

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 Palisades Nuclear Plant Entergy Nuclear Operations, Inc. Covert, MI Docket: 50-255 License: DPR-20 Licensee Emergency Classification Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable

SUBJECT:

PALISADES FORCED SHUTDOWN FOR GREATER THAN 72 HOURS TO REPLACE LEAKING CONTROL ROD DRIVE SEALS DESCRIPTION:

On February 17, 2009, the licensee shut the plant down using normal shutdown procedures due to a leaking Control Rod Drive (CRD) seal.

Over the weekend, prior to the plant shut down, the licensee noted a rapid rate increase on the leak rate for control rod 34, this rapid increase, prior to the shutdown, is indicative of a CRD seal failing. The elevated leakage rate and upward trend prompted a licensee decision to shut down in order to repair the leaking seals.

While limited CRD seal leakage is not unusual for the CRD seal design at Palisades, elevated CRD seal leakage rates and increasing leak-rate trends are indicators of CRD seal degradation. The site has experienced elevated CRD seal leakage rates and increasing leak-rate trends in the past which required similar plant shutdowns.

CRD leakage is routed to the containment sump where it is collected and processed. The leakage creates no unmonitored offsite dose impact nor did the CRD leakage impact safety system performance.

The duration of the shutdown is expected to exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The state of Michigan has been informed.

NRC inspectors will continue to monitor the shutdown, repair, and restart activities.

The information in this preliminary notification has been reviewed with licensee management and is current as of 10:00 a.m. on February 18, 2009.

CONTACTS: John Ellegood John Giessner 269/764-8971 630/829-9619