ENS 46091
From kanterella
Jump to navigation
Jump to search
ENS Event | |
|---|---|
22:07 Jul 13, 2010 | |
| Title | Containment Overpressure Not Ensured in the Appendix R Analysis |
| Event Description | A review of the Appendix R analyses conducted as part of the transition to National Fire Protection Association (NFPA) 805 indicates a potential for the loss of Containment Overpressure (COP) if drywell cooling is not secured or due to fire induced spurious operation of certain primary containment isolation valves. During all Appendix R scenarios, the plant is analyzed to conduct post fire plant cool down with the MSIVs closed, and with Torus cooling provided by the Residual Heat Removal (RHR) system. Based on current design basis calculations, should the containment be depressurized due to a 'smart fire' adequate Net Positive Suction Head (NPSH) may not be available to support Residual Heat Removal (RHR) pump operation during an Appendix R fire event. The design calculations credit COP during Appendix R fire events to provide adequate NPSH to the RHR pumps, as Torus temperature may reach approximately 217 degrees, with a corresponding containment pressure of approximately 10 psig.
There are five scenarios identified where a potential exists for COP loss. One or more of these scenarios could affect several Appendix R analysis areas. The loss of COP could affect safe shutdown capability during an Appendix R fire event. This condition is being reported under 10 CFR 50.72 (b)(3)(ii) as a condition that results in the plant being in an unanalyzed condition which significantly degrades plant safety. Hourly fire patrols have been established for the susceptible fire areas that do not contain both fire detection and suppression equipment. This includes several areas of the reactor and control buildings. This issue is a noncompliance with the current design basis, and does not result in the inoperability of any Technical Specification nor Technical Requirements Manual systems. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Cooper  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+0.23 h0.00958 days <br />0.00137 weeks <br />3.15054e-4 months <br />) | |
| Opened: | John Meyers 22:21 Jul 13, 2010 |
| NRC Officer: | Charles Teal |
| Last Updated: | Jul 13, 2010 |
| 46091 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 46091\u003C/a\u003E - \u003Ca href=\"/Cooper\" title=\"Cooper\"\u003ECooper\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EContainment Overpressure Not Ensured in the Appendix R Analysis\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 46091 - Cooper\n","link":"","lat":40.359658333333336,"lon":-95.65465277777778,"icon":"/w/images/7/79/Entergy_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 544252019-12-05T14:10:0005 December 2019 14:10:00
[Table view]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 Fire Door Discovered Unlatched ENS 508542015-02-27T23:56:00027 February 2015 23:56:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Concerning Control Room Habitability Analysis ENS 494862013-10-30T16:17:00030 October 2013 16:17:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 460912010-07-13T22:07:00013 July 2010 22:07:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Containment Overpressure Not Ensured in the Appendix R Analysis 2019-12-05T14:10:00 | |
Retrieved from "https://kanterella.com/w/index.php?title=ENS_46091&oldid=425159"