ENS 46741
ENS Event | |
|---|---|
15:24 Apr 8, 2011 | |
| Title | Unsealed Flood Barrier Penetration |
| Event Description | During investigations of flood barrier penetrations, one approximately 4 inch conduit has been identified that is not sealed. Reducers are installed in the conduit on the exterior side. This conduit penetrates the auxiliary building into room 56. Flooding through the penetrations could have impacted the ability of the station's safety related equipment in the auxiliary building to perform their design accident mitigation functions.
During investigations of flood barrier penetrations, a drain flow path from the CARP building into Room 23 of the Auxiliary Building [was identified]. There is no specific procedural guidance to isolate this flow path in the event of a flood above 1007 feet. Flooding through this flow path could have impacted the ability of the station's safety related equipment to perform their design accident mitigation functions. This eight-hour notification is being made pursuant to 10 CFR 50.72 (b)(3)(v)(D). The penetrations and CARP building drains are at an approximate elevation of 1007 feet. The river level has been less than 997 feet Mean Sea Level (MSL) since prior to December 1, 2010. The safety related equipment is currently operable. There are not any indications of conditions that might result in a flood. Compensatory actions have been identified. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Fort Calhoun  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-1.73 h-0.0721 days <br />-0.0103 weeks <br />-0.00237 months <br />) | |
| Opened: | Erick Matzke 13:40 Apr 8, 2011 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Apr 8, 2011 |
| 46741 - 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 46741\u003C/a\u003E - \u003Ca href=\"/Fort_Calhoun\" title=\"Fort Calhoun\"\u003EFort Calhoun\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EUnsealed Flood Barrier Penetration\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 46741 - Fort Calhoun\n","link":"","lat":41.520963888888886,"lon":-96.07684444444445,"icon":"/w/images/6/6a/Omaha_Public_Power_District_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |