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Category:NRC Preliminary Notification of Event/Occurrence
MONTHYEARPNO-III-18-002, Beaver Valley, Davis-Besse, Perry Notification of Bankruptcy Filing by Firstenergy Solutions2018-04-0404 April 2018
PNO-III-18-002: Beaver Valley, Davis-Besse, Perry Notification of Bankruptcy Filing by Firstenergy Solutions
PNO-III-16-004, A - Unplanned Shutdown of Davis-Besse Nuclear Power Station for Greater than 72 Hours - Update2016-09-23023 September 2016
PNO-III-16-004A - Unplanned Shutdown of Davis-Besse Nuclear Power Station for Greater than 72 Hours - Update
ML16257A2032016-09-13013 September 2016
PNO-III-16-004, Davis-Besse Nuclear Power Station, Unplanned Shutdown for Greater than 72 Hours
PNO-III-15-006, Davis-Besse Shutdown Due to Secondary Side Steam Line Rupture2015-05-13013 May 2015
PNO-III-15-006: Davis-Besse Shutdown Due to Secondary Side Steam Line Rupture
PNO-III-14-003, A - Update to Davis-Besse Shield Building Restoration2014-04-28028 April 2014
PNO-III-14-003A - Update to Davis-Besse Shield Building Restoration
ML14050A0262014-02-19019 February 2014
PNO-III-14-003: Davis-Besse Shield Building Voids
PNO-III-13-007, Davis-Besse Shield Building Laminar Cracks2013-09-20020 September 2013
PNO-III-13-007 Davis-Besse Shield Building Laminar Cracks
PNO-III-13-006, A: Davis Besse Preliminary Notification Update Unplanned Shutdown Greater than 72 Hours on June 29, 2013, Due to Trip of Reactor Coolant Pump and Subsequent Discovery of Reactor Pressure Boundary Leakage2013-07-15015 July 2013
PNO-III-13-006A: Davis Besse Preliminary Notification Update Unplanned Shutdown Greater than 72 Hours on June 29, 2013, Due to Trip of Reactor Coolant Pump and Subsequent Discovery of Reactor Pressure Boundary Leakage
ML13184A1762013-07-0202 July 2013
PNO-III-13-006 - Davis Besse Unplanned Shutdown Greater than 72 Hours on June 26, 2013, Due to Trip of Reactor Coolant Pump and Subsequent Discovery of Reactor Pressure Boundary Leakage
PNO-III-11-014, Davis-Besse Shield Building Indications2011-10-20020 October 2011
PNO-III-11-014, Davis-Besse Shield Building Indications
PNO-III-10-011, DAVIS-BESSE Start-Up of Following Repairs of Control Rod Drive Mechanism Nozzle Flaw Indications2010-06-29029 June 2010
PNO-III-10-011 - DAVIS-BESSE Start-Up of Following Repairs of Control Rod Drive Mechanism Nozzle Flaw Indications
PNO-III-10-008, Davis-Besse, Public Availability of Two NRC Employee Differing Professional Opinions Concerning Past Issues at Davis-Besse2010-05-20020 May 2010
PNO-III-10-008: Davis-Besse, Public Availability of Two NRC Employee Differing Professional Opinions Concerning Past Issues at Davis-Besse
PNO-III-10-003, A - Davis-Besse Nuclear Power Station - Update - Davis-Besse Control Rod Drive Mechanism Nozzle Indications2010-04-12012 April 2010
PNO-III-10-003A - Davis-Besse Nuclear Power Station - Update - Davis-Besse Control Rod Drive Mechanism Nozzle Indications
ML1007503172010-03-16016 March 2010
PNO-III-10-003 - Davis-Besse Nuclear Power Station - Davis-Besse Control Rod Drive Mechanism Nozzle Indications
PNO-III-09-005, A: Davis-Besse, Transitory Alert Due to Electric Device Failure (Update)2009-06-29029 June 2009
PNO-III-09-005A: Davis-Besse, Transitory Alert Due to Electric Device Failure (Update)
ML0917706352009-06-26026 June 2009
PNO-III-09-005: Davis-Besse, Transitory Alert Due to Electric Device Failure
PNO-III-06-002, Security Event at Davis-Besse2006-01-23023 January 2006
PNO-III-06-002-Security Event at Davis-Besse
PNO-III-04-008, Davis Besse Issued 08/04/2004 Re Automatic Reactor Shutdown2004-08-0404 August 2004
PNO-III-04-008: Davis Besse Issued 08/04/2004 Re Automatic Reactor Shutdown
PNO-III-04-003, Shutdown of the Davis-Besse Nuclear Power Station Plant for Greater than 72 Hours2004-03-17017 March 2004
PNO-III-04-003: Shutdown of the Davis-Besse Nuclear Power Station Plant for Greater than 72 Hours
PNO-III-03-010, Davis Besse: Fuel Loading2003-02-21021 February 2003
PNO-III-03-010, Davis Besse: Fuel Loading
PNO-III-02-036, Crack Identified in Vessel Head Stainless Steel Liner2002-09-10010 September 2002
PNO-III-02-036: Crack Identified in Vessel Head Stainless Steel Liner
ML0308703762002-09-10010 September 2002
Preliminary Notification of Event or Unusual Occurrence -- PNO-III-02-036
PNO-III-02-016, A; Discrete Radioactive Particles Found Outside the Radiologically Restricted Area, Davis-Besse Update2002-04-24024 April 2002
PNO-III-02-016A; Discrete Radioactive Particles Found Outside the Radiologically Restricted Area, Davis-Besse Update
PNO-III-02-006, B, Davis Besse - Reactor Vessel Head Degradation (Second Update)2002-04-0505 April 2002
PNO-III-02-006B, Davis Besse - Reactor Vessel Head Degradation (Second Update)
ML0235800962002-03-11011 March 2002
E-mail from PN1 to Events, Front, PN1, PN302006, Davis-Besse - Update - Significant Metal Loss Observed in Reactor Vessel Head
2018-04-04
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PRELIMINARY NOTIFICATION - REGION III April 28, 2014 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-14-003A This preliminary notification constitutes an update to a previously issue notification which was of interest.
Facility Licensee Emergency Classification Davis-Besse Nuclear Power Station __Notification of Unusual Event FirstEnergy Nuclear Operating Company __Alert Oak Harbor, OH __Site Area Emergency Docket: 50-346 __General Emergency License: NPF-3 X Not Applicable
SUBJECT:
UPDATE TO DAVIS-BESSE SHIELD BUILDING RESTORATION On February 14, 2014, the licensee informed the NRC that it had discovered an unfilled area (void) in the concrete along the top of the 2011 construction opening on the inside wall of the Davis-Besse shield building. The void occurred as a result of the process used to pour concrete during restoration of the 2011 construction opening associated with the reactor pressure vessel head replacement. The void condition was discovered while the plant was shut down for the 2014 steam generator replacement outage. Subsequently, the licensee performed an operability evaluation of the shield building and determined that the shield building could have performed its intended safety functions despite the existence of the void. During the licensees creation of a new construction opening to support the 2014 steam generator replacement outage, the process used to create the new construction opening damaged some of the shield building reinforcement bars (rebar). The rebar damage was not present while the plant was operating and when the shield building was required to be operable. The licensee repaired the void and damaged rebar prior to restoring the shield building construction opening for the 2014 outage.
The NRC reviewed the licensees operability evaluation, which analyzed the impacts of the concrete void during the previous operating cycles and verified that the shield building could have fulfilled its intended safety functions, even with the existence of the concrete void. In particular, the NRC concluded that the shield building remained capable of maintaining structural integrity and protecting the containment vessel against impacts from external objects despite the presence of the concrete void.
The NRC also conducted a wide range of activities, during the 2014 outage, to ensure that the shield building was restored to its design bases in accordance with procedural requirements and the applicable codes and standards. The NRC inspectors directly observed, monitored, and evaluated the licensees repair of damaged shield building rebar and the void, and the pouring and testing of concrete during the restoration of the 2014 shield building construction opening.
The NRC inspectors verified that the shield building void and the damaged rebar were adequately repaired, and that the licensee implemented adequate corrective actions to preclude the formation of another void during the restoration of the 2014 construction opening.
PNO-III-14-003A Details of the NRCs review and conclusions will be documented in an NRC inspection report that will be available to the public after completion of the ongoing NRC steam generator replacement inspection. Subsequently, the public will be provided the opportunity to discuss the NRCs activities associated with this issue during the NRCs annual performance assessment end-of-cycle public outreach for Davis-Besse. The specific date and location of the public outreach will be publically announced in the near future.
This preliminary notification is issued for information only. State officials have been informed.
The information presented herein has been discussed with the licensee and is current as of April 28, 2014, 10:10 a.m. (EDT).
ADAMS Accession Number: ML14118A185 CONTACT: David Hills, DRS 630-829-9733 David.Hills@nrc.gov Jamnes Cameron, DRP 630-829-9833 Jamnes.Cameron@nrc.gov
