ENS 47512: Difference between revisions
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StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
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| event date = 12/08/2011 17:55 EST | | event date = 12/08/2011 17:55 EST | ||
| last update date = 02/07/2012 | | last update date = 02/07/2012 | ||
| title = Unanalyzed Condition Potentially Could Affect | | title = Unanalyzed Condition Potentially Could Affect the Common Control Room | ||
| event text = At 1755 on 12/8/11, it was determined that an unanalyzed condition existed for the common Control Room for both Units. A high energy line break (HELB) barrier issue was discovered while performing a fire barrier surveillance and the condition is believed to have existed from initial plant construction. A HELB barrier was found to have a significant breach in it that could allow steam from a HELB in the Unit 2 Steam Generator Blowdown system to potentially impact equipment in the Control Room. The Control Room is not analyzed for a steam environment. The degree of the impact could not be readily determined, but could likely affect the safety related equipment in the Control Room. At 1803 on 12/8/11, Unit 2 Steam Generator Blowdown was secured to eliminate the potential for a HELB in the affected area which eliminated the potential unanalyzed condition. Therefore, an 8 hour report to the NRC is required under 10 CFR 50.72(b)(3)(ii)(B) 'Any event or condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety' since there was not a reasonable expectation that the Control Room environment could support operation of safety related equipment with Unit 2 Steam Generator Blowdown in service. Further analysis is underway. | | event text = At 1755 on 12/8/11, it was determined that an unanalyzed condition existed for the common Control Room for both Units. A high energy line break (HELB) barrier issue was discovered while performing a fire barrier surveillance and the condition is believed to have existed from initial plant construction. A HELB barrier was found to have a significant breach in it that could allow steam from a HELB in the Unit 2 Steam Generator Blowdown system to potentially impact equipment in the Control Room. The Control Room is not analyzed for a steam environment. The degree of the impact could not be readily determined, but could likely affect the safety related equipment in the Control Room. At 1803 on 12/8/11, Unit 2 Steam Generator Blowdown was secured to eliminate the potential for a HELB in the affected area which eliminated the potential unanalyzed condition. Therefore, an 8 hour report to the NRC is required under 10 CFR 50.72(b)(3)(ii)(B) 'Any event or condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety' since there was not a reasonable expectation that the Control Room environment could support operation of safety related equipment with Unit 2 Steam Generator Blowdown in service. Further analysis is underway. | ||
The licensee will notify the NRC Resident Inspector | The licensee will notify the NRC Resident Inspector | ||
Latest revision as of 22:04, 1 March 2018
| Where | |
|---|---|
Calvert Cliffs  Maryland (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+1.43 h0.0596 days <br />0.00851 weeks <br />0.00196 months <br />) | |
| Opened: | Brian Hayden 00:21 Dec 9, 2011 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Feb 7, 2012 |
| 47512 - NRC Website
| |