ENS 47508
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ENS Event | |
|---|---|
01:00 Nov 17, 2011 | |
| Title | Postulated Flooding Scenario Results in Unanalyzed Condition |
| Event Description | On November 16, 2011, at 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> (EST), control room operators accepted the results of an immediate investigation related to the adequacy of a calculation related to the flooding analysis for service water piping in the control complex. The conclusions of the original analysis assumed operator actions to mitigate the flooding. The existing procedural guidance at that time lacked specificity for the required operator actions. This was identified as a non-conforming condition with respect to a USAR flooding analysis. The immediate investigation determined that significant margin exists for mitigation of the service water leakage crack compared to the 30 minute actions required in the original analysis. A preliminary strategy for flood mitigation was identified in the immediate investigation. Guidance was provided to the operators for a leak mitigation strategy in a night order, and a prompt functionality assessment was requested for the control complex building with respect to the flooding analysis. On November 22, 2011, at 1957 hours0.0227 days <br />0.544 hours <br />0.00324 weeks <br />7.446385e-4 months <br /> (EST), the prompt functionality assessment was accepted by the control room operators. The assessment included compensatory measures that simplified guidance for mitigating the flooding from the service water system. The compensatory measures were implemented. On December 2, 2011, the NRC Component Design Basis Inspection team debriefed that the condition identified should have been called in to the NRC Operations Center within eight hours and that missing the call was a violation of 10 CFR 50.72(b)(3)(ii)(B). On December 7, 2011, at 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br /> (EST), a call was received from the NRC Region III informing the compliance supervisor that the eight-hour notification should still be made.
The NRC Resident Inspector has been notified.
The licensee added further clarification to the event reported above as follows: Given that an unanalyzed condition existed until the appropriate measures were implemented, an eight-hour call in accordance with the aforementioned section of 10 CFR 50.72 should have been made. After further consideration, station management decided the eight-hour call was missed and it is being reported as required. The NRC Resident Inspector has been notified." R3DO (Skokowski) notified. |
| Where | |
|---|---|
Perry  Ohio (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| LER: | 05000440/LER-2011-004 |
| Time - Person (Reporting Time:+497.48 h20.728 days <br />2.961 weeks <br />0.681 months <br />) | |
| Opened: | Thomas Morse 18:29 Dec 7, 2011 |
| NRC Officer: | John Knoke |
| Last Updated: | Dec 10, 2011 |
| 47508 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 564552023-04-06T20:46:0006 April 2023 20:46:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Main Steam Line 'B' Leakage in Excess of Tech Spec Limits ENS 536752018-10-19T04:00:00019 October 2018 04:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot-Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 536442018-10-04T04:00:0004 October 2018 04:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 502132014-06-19T20:28:00019 June 2014 20:28:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to a Postulated Hot Short That Could Affect Safe Shutdown Equipment ENS 494462013-10-17T17:00:00017 October 2013 17:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 475452011-12-21T18:59:00021 December 2011 18:59:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Groundwater Level May Exceed Design Assumptions ENS 475082011-11-17T01:00:00017 November 2011 01:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Flooding Scenario Results in Unanalyzed Condition ENS 470242011-07-05T22:15:0005 July 2011 22:15:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Two Appendix R Wiring Issues That Could Potentially Affect the Ability to Shutdown ENS 436032007-08-27T20:45:00027 August 2007 20:45:00 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 Grating Inside Containment Found Unsecured ENS 420722005-10-21T13:00:00021 October 2005 13:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Relocation of a Fire Door Boundary ENS 414172005-02-17T22:30:00017 February 2005 22:30:00 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 Emergency Diesel Generators Declared Inoperable Due to Unanalyzed Condition ENS 413442005-01-19T07:37:00019 January 2005 07:37:00 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 Emergency Diesel Generators Declared Inoperable Due to an Unanalyzed Condition ENS 404042003-12-22T01:21:00022 December 2003 01:21:00 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 Impact to Safe Shutdown Due to Control Complex Ventilation Inoperability 2023-04-06T20:46:00 | |
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