PNO-III-10-010, A: Update - Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seal

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PNO-III-10-010A: Update - Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seal
ML101870533
Person / Time
Site: Palisades Entergy icon.png
Issue date: 07/06/2010
From: John Ellegood, Robert Orlikowski
NRC/RGN-III
To:
References
PNO-III-10-010A
Download: ML101870533 (1)


PRELIMINARY NOTIFICATION- REGION III July 6, 2010 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-10-010A 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 Utility Emergency Classification Palisades Nuclear Plant Notification of Unusual Event Entergy Nuclear Operations, Inc. Alert Covert, MI Site Area Emergency Docket: 50-255 General Emergency License: DPR-20 X Not Applicable

SUBJECT:

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

On June 24, 2010, the utility shut the plant down using normal shutdown procedures due to a leaking Control Rod Drive (CRD) seal.

The utility had been tracking the leak rate for control rod 22 and noted a rate increase which was indicative of a CRD seal failing. The elevated leakage rate and upward trend prompted the utility to shut down the plant in order to repair the leaking seal.

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.

Control Rod Drive 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.

During the outage, the utility repaired the CRD seal and also replaced a reactor cooling pump seal that showed signs of degradation. On July 2, 2010, the utility restarted the reactor and then proceeded to put the turbine back online.

The NRC inspectors observed the reactor return to criticality and other restart activities.

Region III received notification of the utilitys restart activities by email notification from the resident inspectors on July 2, 2010. The information in this preliminary notification has been reviewed with utility management and is current as of 10:30 a.m. on July 06, 2010.

ADAMS Accession Number ML101870533 CONTACTS: John Ellegood Robert Orlikowski 269/764-8971 630/829-9753