View source for PNO-III-11-010, Palisades - Unplanned Shutdown Greater than 72 Hours and Notification of Unusual Event

{{Adams
| number = ML112630030
| issue date = 09/19/2011
| title = PNO-III-11-010 - Palisades - Unplanned Shutdown Greater than 72 Hours and Notification of Unusual Event
| author name = Ellegood J, Giessner J
| author affiliation = NRC/RGN-III
| addressee name = 
| addressee affiliation = 
| docket = 05000255
| license number = DPR-020
| contact person = 
| document report number = PNO-III-11-010
| document type = NRC Preliminary Notification of Event/Occurrence
| page count = 2
}}
{{#Wiki_filter:PRELIMINARY NOTIFICATION September 19, 2011 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-11-010 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. Some of the information may not yet be fully verified or evaluated by the Region III staff.
Facility                                             Licensee Emergency Classification Palisades Nuclear Plant                                x Notification of Unusual Event Entergy Nuclear Operations, Inc.                         Alert Covert, Michigan                                         Site Area Emergency Docket No: 50-255                                        General Emergency License No: DPR-20                                       Not Applicable

==SUBJECT:==
PALISADES UNPLANNED SHUTDOWN GREATER THAN 72 HOURS AND NOTIFICATION OF UNUSUAL EVENT On September 16, 2011, at 12:59 p.m. (EDT), Palisades Nuclear Plant commenced a shutdown due to unidentified leakage in excess of 1 gallon per minute (gpm) as required by the Technical Specification for the Reactor Coolant System (RCS). At the time the licensee began the shutdown, unidentified leakage was at 3.5 gpm. The licensee determined that the leakage was in containment; therefore, no radioactivity was released to the environment.
During the shutdown, the leakage increased and exceeded 10 gpm. The Emergency Action Level threshold for RCS leakage is 10 gpm and at 2:50 p.m. the licensee declared a Notice of Unusual Event (NOUE) and manually shut down the reactor from 79 percent power. The NOUE is the lowest of the four NRC emergency classification levels. All safety systems functioned as designed and plant safety was not compromised. The maximum leakage observed was 14-15 gpm.
Based on a containment entry, the licensee determined that the leakage was from the packing of a valve. The licensee isolated the leak and the NOUE was terminated at 7:34 p.m. (EDT) after confirmation that the leak had been isolated.
The plant is currently in a stable shutdown condition. The licensee has replaced the packing on the valve. NRC Resident Inspectors responded to the control room and are continuing to monitor the licensees repairs that are necessary for the plant to startup. They will monitor the plants startup activities.
Michigan State officials have been informed of the plant shutdown.
Region III received initial notification of this occurrence by the Headquarters Operations Center from the licensees NOUE notification at 3:04 p.m. (EDT). The information presented herein has been discussed with the licensee, and is current as of September 19, 2011, at 12:00 p.m.
(CDT). This preliminary notification is issued for information only and no further action by the staff is anticipated.

ADAMS Accession Number: ML112630030 CONTACTS: John Ellegood             John Giessner 269/764-8971             630/829-9619 John.Ellegood@nrc.gov    John.Giessner@nrc.gov}}

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