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Category:NRC Preliminary Notification of Event/Occurrence
MONTHYEARPNO-III-19-002, Palisades, Through-Wall Leak Identified on a Reactor Vessel Head Nozzle2018-11-14014 November 2018 PNO-III-19-002: Palisades, Through-Wall Leak Identified on a Reactor Vessel Head Nozzle PNO-III-19-001, Maintenance Outage to Repair Control Rod Drive and Failed Transformer2018-10-18018 October 2018 PNO-III-19-001: Maintenance Outage to Repair Control Rod Drive and Failed Transformer PNO-III-14-002, A: Update, Palisades Control Rod Drive Mechanism Housing Flaws2014-03-14014 March 2014 PNO-III-14-002A: Update, Palisades Control Rod Drive Mechanism Housing Flaws ML14030A1902014-01-30030 January 2014 PNO-III-14-002: Palisades Control Rod Drive Mechanism Housing Flaws PNO-III-13-004, B, Update - Palisades Shutdown Due to Safety Injection Refueling Water Tank (SIRWT) Leakage2013-06-17017 June 2013 PNO-III-13-004B, Update - Palisades Shutdown Due to Safety Injection Refueling Water Tank (SIRWT) Leakage ML13129A4382013-05-0909 May 2013 PNO-III-13-004A - Update: Palisades Shutdown Due to Safety Injection Refueling Water Storage Tank (SIRWT) Leakage ML13126A2702013-05-0606 May 2013 PNO-III-13-004 - Palisades Shutdown Due to Safety Injections Refueling Water Storage Tank Leakage PNO-III-13-002, A - Update - Palisades Shutdown Due to Leakage from the Component Cooling Water (CCW) System2013-02-22022 February 2013 PNO-III-13-002A - Update - Palisades Shutdown Due to Leakage from the Component Cooling Water (CCW) System ML13046A4042013-02-15015 February 2013 PNO-III-13-002, Palisades Shutdown Due to Leakage from the Component Cooling Water (CCW) System ML12314A2712012-11-0909 November 2012 PNO-lll-12-015A (Update) Palisades Shutdown Due to Leakage from the Main Steam System ML12310A5052012-11-0505 November 2012 PNO-lll-12-015, Palisades Shutdown Due to Leakage from the Main Steam System PNO-III-12-012, Palisades Leakage from the Service Water System2012-09-25025 September 2012 PNO-III-12-012: Palisades Leakage from the Service Water System PNO-III-12-007, A, Update, Palisades Shutdown Due to Increase in Unidentified Reactor Coolant System Leakage2012-08-30030 August 2012 PNO-III-12-007A, Update, Palisades Shutdown Due to Increase in Unidentified Reactor Coolant System Leakage PNO-III-12-004, A: Update - Palisades Shutdown Due to Safety Injection Refueling Water Storage Tank Leakage2012-07-11011 July 2012 PNO-III-12-004A: Update - Palisades Shutdown Due to Safety Injection Refueling Water Storage Tank Leakage ML12166A2612012-06-14014 June 2012 PNO-III-12-004 - Palisades Shutdown Due to Safety Injection Refueling Water Storage Tank Leakage PNO-III-11-011, A - Palisades Reactor Trip (Update)2011-10-0303 October 2011 PNO-III-11-011-A - Palisades Reactor Trip (Update) ML11269A2302011-09-26026 September 2011 PNO-III-11-011 Palisades Nuclear Plant Reactor Trip PNO-III-11-010, Palisades - Unplanned Shutdown Greater than 72 Hours and Notification of Unusual Event2011-09-19019 September 2011 PNO-III-11-010 - Palisades - Unplanned Shutdown Greater than 72 Hours and Notification of Unusual Event ML1123601032011-08-23023 August 2011 PNO-II-11-005: North Anna, Emergency Declarations Due to Seismic Event PNO-III-11-003, Palisades Shutdown Due to Loss of Main Generator Electrical Load2011-01-24024 January 2011 PNO-III-11-003, Palisades Shutdown Due to Loss of Main Generator Electrical Load PNO-III-11-001, ; Palisades, Unusual Event and 72-Hour Limiting Condition for Operation Due to 4160 V Ground Fault2011-01-11011 January 2011 PNO-III-11-001; Palisades, Unusual Event and 72-Hour Limiting Condition for Operation Due to 4160 V Ground Fault PNO-III-10-010, A: Update - Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seal2010-07-0606 July 2010 PNO-III-10-010A: Update - Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seal ML1017605222010-06-25025 June 2010 PNO-III-10-010 - Palisades - Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seal PNO-III-09-001, A - Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rob Drive Seal (Update)2009-02-23023 February 2009 PNO-III-09-001A - Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rob Drive Seal (Update) ML0904905272009-02-18018 February 2009 PNO-III-09-001, Palisades Forced Shutdown for Greater than 72 Hours to Replace Leaking Control Rod Drive Seals PNO-III-08-008, A - Palisades - Forced Shutdown to Replace Leaking Control Rod Drive (CRD) Seal Packages (Update)2008-08-11011 August 2008 PNO-III-08-008A - Palisades - Forced Shutdown to Replace Leaking Control Rod Drive (CRD) Seal Packages (Update) ML0822003472008-08-0707 August 2008 PNO-III-08-008 - Palisades Forced Shutdown to Replace Leaking Control Rod Drive Seals PNO-III-08-004, A, Cook and Palisades, Update - Unusual Events Declared Due to Earthquake2008-04-18018 April 2008 PNO-III-08-004A, Cook and Palisades, Update - Unusual Events Declared Due to Earthquake ML0810903102008-04-18018 April 2008 PNO-III-08-004: Cook & Palisades, Unusual Events Declared Due to Earthquake PNO-III-07-006, A: Palisades, Shutdown Due to Low Steam Generator Level (Update)2007-05-14014 May 2007 PNO-III-07-006A: Palisades, Shutdown Due to Low Steam Generator Level (Update) ML0712905812007-05-0909 May 2007 PNO-III-07-006: Palisades Shutdown Due to Low Steam Generator Level PNO-III-07-003, A - Palisades: Shutdown to Replace Heat Damaged Cables (Update)2007-03-0505 March 2007 PNO-III-07-003A - Palisades: Shutdown to Replace Heat Damaged Cables (Update) ML0705805222007-02-27027 February 2007 PNO-III-07-003: Palisades - Palisades Shutdown to Replace Heat-Damaged Cables PNO-III-06-013, Palisades Shutdown to Investigate Control Rod Withdrawal Problem2006-05-11011 May 2006 PNO-III-06-013: Palisades Shutdown to Investigate Control Rod Withdrawal Problem PNO-III-04-010, Palisades Shut Down to Repair Control Rod Drive Mechanism Leakage2004-08-11011 August 2004 PNO-III-04-010: Palisades Shut Down to Repair Control Rod Drive Mechanism Leakage PNO-III-03-040, Fire Adjacent to Palisades Nuclear Generating Station2003-09-22022 September 2003 PNO-III-03-040 - Fire Adjacent to Palisades Nuclear Generating Station PNO-III-03-014, B: Palisades Loss of Shutdown Cooling Caused by Loss of Offsite Power (Second Update)2003-03-28028 March 2003 PNO-III-03-014B: Palisades Loss of Shutdown Cooling Caused by Loss of Offsite Power (Second Update) ML0308605932003-03-27027 March 2003 PNO-III-03-14A: Palisades Loss of Shutdown Cooling Caused by Loss of Offsite Power (Update) PNO-III-03-013, Alert Declared Due to Fire with Potential to Affect Safety Systems2003-03-19019 March 2003 PNO-III-03-013: Alert Declared Due to Fire with Potential to Affect Safety Systems 2018-11-14
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PRELIMINARY NOTIFICATION - REGION III August 30, 2012 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-12-007A 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 __ Notification of Unusual Event Entergy Nuclear Operations, Inc. __ Alert Covert, Michigan __ Site Area Emergency Docket: 05000255 __ General Emergency License: DPR-20 X Not Applicable
SUBJECT:
UPDATE - PALISADES SHUTDOWN DUE TO INCREASE IN UNIDENTIFIED REACTOR COOLANT SYSTEM LEAKAGE This Preliminary Notification updates information discussed in PNO-III-12-007, as a result of the Palisades plant shutdown on August 12, 2012. The shutdown occurred due to rising unidentified leakage from the reactor coolant system of 0.3 gallons per minute. The required shutdown for unidentified leakage is greater than 1 gallon per minute. The NRC dispatched a Special Inspection Team to supplement the resident inspectors in the review and evaluation of the issue.
The licensee reported that the leakage was coming from control rod-drive mechanism (CRDM) 24. There are 45 CRDMs, one associated with each control rod. The control rods are designed to absorb neutrons when they are inserted in the reactor to control the nuclear reaction. The CRDM extends from the reactor head about 14 feet upward, and is the mechanism that withdraws and inserts the rod. The cause of the rise in leakage was determined to be from a crack that went through the CRDM 24 upper housing wall and was located about 2 feet up from the reactor head and was less than 1/8 inch in size. The leak was from the reactor coolant system pressure boundary, and the Technical Specification limit for pressure boundary leakage is 0 gpm. The NRC resident inspectors and the Special Inspection Team monitored the licensees activities to determine the source of the leak, the repair process, and testing, as well as analysis and inspections to determine if other CRDMs may be susceptible to similar failures.
The licensee replaced and retested the CRDM 24 housing. Based on the location of the fault, the licensee concluded that CRDM 24 experienced a through-wall crack due to a type of stress corrosion cracking which occurs under stress and certain water chemistry conditions. The licensee conducted analyses and inspections to determine if other CRDMs may be susceptible to the same failure. This included inspecting eight additional CRDMs to determine if any of the other CRDMs have similar cracks. The inspections identified no additional cracks. In response to NRC questions about some of the inspections and analyses, the licensee performed additional work to ensure the plant was safe to start up. In addition, the Special Inspection Team evaluated the licensees boric acid walkdowns of the reactor vessel head and no damage
was identified. The licensee is currently evaluating the frequency for additional inspections related to the CRDMs. The NRC will review this information to ensure the inspections are adequate.
The NRC team, and regional and headquarters experts also conducted a detailed review of the technical evaluations that were performed to ensure the CRDMs structural integrity met the applicable codes and standards.
On August 30, 2012, the Palisades plant resumed operation after the CRDM 24 repairs were completed and the extent of condition reviewed. The reactor was made critical at 11:26 p.m.
(EDT) on August 29, 2012, and the main generator was synchronized to the grid at 7:18 a.m.
(EDT) on August 30, 2012.
The State of Michigan has been notified.
The meeting summaries for the NRC discussions with the licensee regarding the leak will be available through ADAMS.
The information in this preliminary notification is current as of 2:30 p.m. (EDT) on August 30, 2012.
This information has been reviewed with plant management.
This preliminary notification is issued for information only and no further action by the staff is anticipated.
ADAMS Accession Number: ML12243A485 Contacts: John B. Giessner Thomas Taylor 630-829-9619 269-764-8971 John.Giessner@nrc.gov Thomas.Taylor@nrc.gov
Enclosure:
Palisades Rack and Pinion CRDM
Palisades Rack and Pinion CRDM Enclosure 1