ENS 42327: Difference between revisions
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StriderTol (talk | contribs) (Created page by program invented by Mark Hawes) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
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| event date = 02/10/2006 11:00 CST | | event date = 02/10/2006 11:00 CST | ||
| last update date = 02/10/2006 | | last update date = 02/10/2006 | ||
| title = Potential | | title = Potential for Loss of Safe Shutdown Capability | ||
| event text = 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. | | event text = 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. | 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. | ||
Latest revision as of 22:19, 1 March 2018
| Where | |
|---|---|
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
| |
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 | |