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Category:NRC Preliminary Notification of Event/Occurrence
MONTHYEARML12320A0202012-11-14014 November 2012
Update: PNO-I-12-007A Hurricane Sandy Update Causes Oyster Creek Alert and Shutdowns of Reactors at Nine Mile Point Unit 1, Indian Point Unit 3 and Salem Unit 1
PNO-I-12-007, Hurricane Sandy Causes Oyster Creek Alert and Shutdowns of Reactors at Nine Mile Point Unit 1, Indian Point Unit 3, and Salem Unit 12012-10-31031 October 2012
PNO-I-12-007 - Hurricane Sandy Causes Oyster Creek Alert and Shutdowns of Reactors at Nine Mile Point Unit 1, Indian Point Unit 3, and Salem Unit 1
PNO-I-12-005, Oyster Creek Reactor Shutdown and Unusual Event Due to a Loss of Offsite Power and Shutdown Greater than 72 Hours2012-07-31031 July 2012
PNO-I-12-005 - Oyster Creek Reactor Shutdown and Unusual Event Due to a Loss of Offsite Power and Shutdown Greater than 72 Hours
ML1123601032011-08-23023 August 2011
PNO-II-11-005: North Anna, Emergency Declarations Due to Seismic Event
PNO-I-09-005, A: Update: Oyster Creek Reactor Trip and Unusual Event Due to a Loss of Offsite Power and Shutdown Greater than 72 Hours2009-07-17017 July 2009
PNO-I-09-005A: Update: Oyster Creek Reactor Trip and Unusual Event Due to a Loss of Offsite Power and Shutdown Greater than 72 Hours
ML0919604862009-07-15015 July 2009
PNO-I-09-005: Exelon Generation Co. Llc., Oyster Creek Reactor Trip and Unusual Event Due to a Loss of Offsite Power and Shutdown Greater than 72 Hours
PNO-I-09-002, A: Oyster Creek, Update - Shutdown Greater than 72 Hours: Manual Reactor Scram Following Loss of Cooling to Main Transformer, Dated 05/04/20092009-05-0404 May 2009
PNO-I-09-002A: Oyster Creek, Update - Shutdown Greater than 72 Hours: Manual Reactor Scram Following Loss of Cooling to Main Transformer, Dated 05/04/2009
ML0911706642009-04-27027 April 2009
PNO-I-09-002 - Oyster Creek, Shutdown Greater than 72 Hours: Manual Reactor Scram Following Loss of Cooling to Main Transformer
PNO-I-09-001, A: Exelon Generation Company, LLC, Update - Oyster Creek Unusual Event and Automatic Reactor Scram Due to Fire in M1A Main Transformer2009-02-0505 February 2009
PNO-I-09-001A: Exelon Generation Company, LLC, Update - Oyster Creek Unusual Event and Automatic Reactor Scram Due to Fire in M1A Main Transformer
ML0903304152009-02-0202 February 2009
PNO-I-09-001: Unusual Event and Automatic Reactor Scram Due to a Fire in the M1A Main Transformer at Oyster Creek Station
PNO-I-08-013, A - Update - Oyster Creek: Automatic Reactor Scram Due to Main Transformer Fault2008-12-0505 December 2008
PNO-I-08-013A - Update - Oyster Creek: Automatic Reactor Scram Due to Main Transformer Fault
ML0833602712008-12-0101 December 2008
PNO-I-08-013: Shutdown Greater than 72 Hrs: Automatic Reactor Scram Due to Main Transformer Fault - Oyster Creek
ML0914703712008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Primary Containm
ML0914703692008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek Renewal Commitments Related to the Drywall Primary Containm
ML0914703702008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywell Primary
ML0914703722008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Primary Containm
ML0914804412008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Primary Containm
ML0914804422008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywall Primary
ML0914804432008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywall Primary
ML0914804442008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Primary Containm
ML0914804452008-11-30030 November 2008
Draft Preliminary Notification of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Primary Containment Drywe
ML0914804462008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Facility Amergen Energy Company, LLC, Oyster Creek, Subject - Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywell Primary
ML0919605922008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX, Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywell Primary Containment
ML0919605932008-11-30030 November 2008
Draft Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-XXX Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywell Primary Containment
ML0911907252008-11-17017 November 2008
Preliminary Notification of Event of Unusual Occurrence, PNO-1-08-012; Subject Results of Implementation of Oyster Creek License Renewal Commitments Related to the Drywell Primary Containment, with Hand Written Notes
ML0911906532008-11-17017 November 2008
E-mail from K. Heater of USNRC to Various, Regarding PNO-I-08-012: Oyster Creek - Results of Implementation of License Renewal Commitments
ML0914606862008-11-14014 November 2008
E-mail from J. Richmond of USNRC to Various, Regarding Oc PNO - Nov 2008 Drywell Rev 3
ML0919004242008-11-0707 November 2008
E-mail from R. Conte of USNRC to J. Richmond, D. Tifft and D. Pelton of USNRC, Regarding Oyster Creek Preliminary Notification(Draft) and Communications Plan, Rev. 1
PNO-I-07-006, A - NRC Resident Inspector - Update - Reactor Scram on Low Reactor Vessel Water Level Due to a Trip of the 'C' Reactor Feed Pump2007-07-23023 July 2007
PNO-I-07-006A - NRC Resident Inspector - Update - Reactor Scram on Low Reactor Vessel Water Level Due to a Trip of the 'C' Reactor Feed Pump
ML0719904282007-07-17017 July 2007
PNO-I-07-006: Reactor Scram on Low Reactor Vessel Water Level Due to a Trip of the C Reactor Feed Pump
PNO-I-06-012, Oyster Creek, Evaluation of Containment Design Function2006-11-0909 November 2006
PNO-I-06-012: Oyster Creek, Evaluation of Containment Design Function
PNO-I-05-022, Alert Declaration at Oyster Creek2005-08-0808 August 2005
PNO-I-05-022 - Alert Declaration at Oyster Creek
ML0713401372003-05-22022 May 2003
Reactor Operating Events Event Notification Report, Event Number: 39876; Facility: Oyster Creek; Notification Date: 05/22/2003
PNO-I-03-016, Oyster Creek Bargaining Unit Strike at Oyster Creek (39876)2003-05-22022 May 2003
PNO-I-03-016: Oyster Creek Bargaining Unit Strike at Oyster Creek (#39876)
PNO-I-02-020, Unusual Event Due to a Hydrogen Gas Ignition in the Off-Gas System (39348)2002-11-0707 November 2002
PNO-I-02-020: Unusual Event Due to a Hydrogen Gas Ignition in the Off-Gas System (#39348)
2012-07-31
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Date: July 31, 2012 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-I-12-005 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 staff on this date.
Facility Licensee Emergency Classification Exelon Generation Company, LLC X Notification of Unusual Event Oyster Creek Alert Forked River, NJ Site Area Emergency Docket: 50-219 General Emergency Not Applicable
SUBJECT:
OYSTER CREEK REACTOR SHUTDOWN AND UNUSUAL EVENT DUE TO A LOSS OF OFFSITE POWER AND SHUTDOWN GREATER THAN 72 HOURS On July 23, at 3:29 a.m., Oyster Creek automatically shutdown following a loss of offsite power (LOOP) due to an electrical fault on an offsite transmission line. All control rods inserted during the scram. The licensee declared an Unusual Event (UE) at 3:41 a.m. because the LOOP exceeded 15 minutes in duration. Both isolation condensers (ICs) actuated to cool the reactor.
As a result of the loss of offsite power, both emergency diesel generators (EDGs) automatically started and provided electrical power to safety equipment. As expected, due to the LOOP and before the EDGs started, power was interrupted to the reactor protection system which caused a primary containment isolation. Plant operators used the isolation condenser, the electromatic relief valves (EMRVs) and the control rod drive pumps to control reactor pressure and level.
Offsite power was restored at 4:57 a.m., and the UE terminated at 5:38 a.m. on July 23. The licensee achieved cold shutdown on July 24.
The electrical system transmission operator determined that the loss of offsite power was the result of an electrical ground caused by a tree contacting one transmission line, as well as an unrelated electrical circuit breaker coordinator problem that affected the other transmission line running between Oyster Creek and its connection to the electrical grid. The transmission system operator repaired these problems.
In addition, Exelon initially reported to the NRC that the reactor building (secondary containment) differential pressure indicated positive 0.25 inches at 3:57 a.m., but returned to its normal negative pressure at 4:34 a.m. The cause was determined to be instrument error due to loss of instrument air, and secondary containment pressure actually remained at its normal, negative value throughout this event. Exelon will update this event report in the near future.
The resident inspectors responded to the site and closely monitored licensee actions to stabilize the plant, restore offsite power, and troubleshoot plant systems. Regional specialists assisted the resident staff in reviewing Exelons actions to address equipment issues before plant restart.
Following the repairs to the offsite electrical system by the transmission system operator, and verification of the operability of onsite plant systems, Exelon restarted the plant on June 26.
The plant reached 100% power on July 28.
The State of New Jersey was informed at the time of the event. The NRC Region I Public Affairs Office responded to media inquiries.
The information presented herein was discussed with Exelon and is current as of July 30, 2012 at 9:15 am. This PN is being issued to describe the conditions that were found to have caused this plant shutdown as well as to discuss the subsequent restart of the unit. Accordingly, no update to this PN will be issued.
ADAMS Accession Number: ML12214A163 CONTACT: Scott Barber (610) 337-5232
ML12214A163 Non-Sensitive Publicly Available x SUNSI Review Sensitive Non-Publicly Available OFFICE RI/DRP RI/SLO RI/PAO RI/DRP RI/DRP RI/ORA NAME SBarber/AMD for DTifft/ DBT DScrenci/DS GHunegs/GKH WDean/WMD DRoberts/JWC for DATE 07/30 /12 07/30 /12 07/ 30 /12 07/30 /12 07/31/12 07/ 31 /12