ENS 42327
ENS Event | |
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17:00 Feb 10, 2006 | |
Title | Potential for Loss of Safe Shutdown Capability |
Event Description | As a result of Wolf Creek's 2005 Triennial Fire Protection Inspection, a re-evaluation of concerns described in NRC Information Notice (IN 92-18), 'POTENTIAL FOR LOSS OF REMOTE SHUTDOWN CAPABILITY DURING A CONTROL ROOM FIRE' was performed. During that re-evaluation it was identified that in the event of a fire in the control room, 39 motor operated valves (MOVs) credited for post-fire safe shutdown could potentially fail in an unanalyzed condition. Of those 39 MOVs, failure of 4 of them could potentially prevent achieving and maintaining safe shutdown (SSD) conditions.
In the 39 MOV circuits identified above, an intra-cable hot short between one conductor on the hot side of the indication circuit and another conductor on the load side of the control room hand switch could bypass the torque switch and energize either the open or close coil. If this occurs, the open or close contactor will close and the motor will operate in either the open or close direction until the motor stalls, possibly resulting in damage to the valve such that it cannot be manually operated. Present system operability is not affected as there has been no occurrence of a fire in the Control Room and compensatory actions are in place to detect and mitigate the effects of a fire in the Control Room. Actions taken or planned: An hourly fire watch was established in the Control Room due to a previous condition identified on 11/16/2005 in accordance with AP 10-104, Breech procedure. The condition identified today will be referenced on the active Breach Request that was implemented on 11/16/2005. The licensee notified the NRC Resident Inspector. |
Where | |
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Wolf Creek Kansas (NRC Region 4) | |
Reporting | |
10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor | |
Time - Person (Reporting Time:+-0.9 h-0.0375 days <br />-0.00536 weeks <br />-0.00123 months <br />) | |
Opened: | Dave Dees 16:06 Feb 10, 2006 |
NRC Officer: | Bill Gott |
Last Updated: | Feb 10, 2006 |
42327 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
Wolf Creek with 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
WEEKMONTHYEARENS 526662017-04-05T19:00:0005 April 2017 19:00:00
[Table view]10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for Both Edg Transfer Line Connections ENS 506282014-11-19T21:37:00019 November 2014 21:37:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 504682014-09-18T16:55:00018 September 2014 16:55:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 494232013-10-09T22:30:0009 October 2013 22:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 481742012-08-09T23:45:0009 August 2012 23:45:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Control Building A/C Unit May Not Perform Design Function on Loss of Redundant A/C Unit ENS 481342012-07-25T21:02:00025 July 2012 21:02:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Identification of a Degraded or Unanalyzed Condition ENS 475902012-01-13T20:03:00013 January 2012 20:03:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Notification of Unusual Event and Reactor Trip Due to Loss of Offsite Power ENS 474122011-11-03T21:00:0003 November 2011 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for a Postulated Control Room Fire ENS 470762011-07-20T18:15:00020 July 2011 18:15:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Fire Protection Program Concern ENS 469092011-06-01T18:15:0001 June 2011 18:15:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Both Trains of Component Cooling Water Declared Inoperable Due to Voiding ENS 464882010-12-17T21:35:00017 December 2010 21:35:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Potential Equipment Actuations Due to Electrical Short Circuits ENS 464282010-11-18T22:26:00018 November 2010 22:26:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Post Fire Safe Shutdown Unanalyzed Condition ENS 461962010-08-21T22:00:00021 August 2010 22:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition One Train Eccs Declared Inoperable Due to Void in "a" Rhr Heat Exchanger ENS 461362010-07-28T19:22:00028 July 2010 19:22:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Three Auxiliary Feedwater (Afw) Trains Declared Inoperable ENS 458592010-04-20T18:07:00020 April 2010 18:07:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Five Potential Issues Discovered During Post-Fire Safe Shutdown Review ENS 456922010-02-10T00:00:00010 February 2010 00:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Post Fire Safe Shutdown Unanalyzed Condition ENS 452772009-08-19T20:00:00019 August 2009 20:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Time to Establish Charging Flow Exceeded Thermal Hydraulic Analysis ENS 445862008-10-21T05:00:00021 October 2008 05:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition During Design Basis Fire in Area A-27 of Auxiliary Building ENS 441722008-04-26T18:18:00026 April 2008 18:18:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Discovered Due to Improperly Installed Fuse Wiring in Class 1E Air Conditioning Unit ENS 441312008-04-10T15:15:00010 April 2008 15:15:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition "Analysis Indicates Containment Coolers May Not Have Automatically Started in Slow Speed Following Postulated Main Steam Line Break ENS 438922008-01-11T00:12:00011 January 2008 00:12:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Voiding Discovered in High Head and Intermediate Head Si Common Suction ENS 426032006-05-24T15:38:00024 May 2006 15:38:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Discovered During Post-Fire Safe Shutdown Area Review ENS 423272006-02-10T17:00:00010 February 2006 17:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential for Loss of Safe Shutdown Capability ENS 421822005-12-02T00:30:0002 December 2005 00:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Emergency Diesel Capability ENS 421462005-11-16T21:30:00016 November 2005 21:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Failure to Meet Required Response Times for Shutdown Outside Control Room ENS 420292005-09-30T14:45:00030 September 2005 14:45:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Vulnerabilities Discovered During Design Basis Fire Review ENS 417862005-05-10T21:55:00010 May 2005 21:55:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Emergency Safety System Actuation Dampers Inoperable ENS 413272005-01-13T01:45:00013 January 2005 01:45:00 Other Unspec Reqmnt, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 24 Hour Condition of License Report Regarding Halon System- Actuator Connection Error ENS 413172005-01-07T23:00:0007 January 2005 23:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Loss of a Fire Safe Shutdown Success Path ENS 405962004-03-17T20:57:00017 March 2004 20:57:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - 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