ENS 43405
ENS Event | |
---|---|
00:08 Jun 5, 2007 | |
Title | Fire Safe Shutdown Capability Impacted by a Breaker Coordination Issue |
Event Description | An engineering analysis has identified existing breaker coordination issues and their effect on plant fire protection and resulting safe shutdown capability. Cables associated with certain breakers do not have qualified fire barriers in place to prevent an upstream breaker from tripping. The affected cables are in fire areas that credit the affected train as the assured post fire safe shutdown train. The failure mode of concern is that a fire in the area where the cable is located could cause a short circuit between the cable connectors."
The fault current calculated for these cases is high enough to trip the upstream breaker(s) and it cannot be assured that the downstream load breaker(s) will act to clear the fault first. [This] event was initially discovered on 5/17/07. Mitigative actions were taken at that time, in the form of establishing fire watches for the affected fire areas. Reportability implications were discovered as a result of additional discussions that took place on 6/4/07. The following cables and power sources are impacted by this notification: CABLE NO. FIRE AREA AFFECTED PANEL 1CA581 Unit 1 Auxiliary Feedwater Pump Turbine Control Panel Room 1EDF 2CA581 Unit 2 Auxiliary Feedwater Pump Turbine Control Panel Room 2EDF 1IRE761 Unit 1 577 elevation Electrical Penetration Room 1EPD 2IRE761 Unit 2 577 elevation Electrical Penetration Room 2EPD Panels 1EDF and 2EDF are 125 VDC Vital Instrumentation and Control Auctioneered Distribution Centers. Loads fed from these distribution centers include Train 'B' circuits associated with the following: 4 KV Essential Switchgear Control Power, Diesel Generator Load Sequencer Control Power, and Auxiliary Feedwater System Control Power. Panels 1EPD and 2EPD are 125VDC Vital Instrumentation and Control Panel boards. These panel boards supply a variety of Train 'B' safety related control power loads. The licensee will notify the NRC Resident Inspector. |
Where | |
---|---|
Catawba ![]() South Carolina (NRC Region 2) | |
Reporting | |
10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
Time - Person (Reporting Time:+-2.23 h-0.0929 days <br />-0.0133 weeks <br />-0.00305 months <br />) | |
Opened: | Larry White 21:54 Jun 4, 2007 |
NRC Officer: | Pete Snyder |
Last Updated: | Jun 4, 2007 |
43405 - 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 43405\u003C/a\u003E - \u003Ca href=\"/Catawba\" title=\"Catawba\"\u003ECatawba\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EFire Safe Shutdown Capability Impacted by a Breaker Coordination Issue\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 43405 - Catawba\n","link":"","lat":35.05162222222222,"lon":-81.06938055555555,"icon":"/w/images/7/75/Duke_Energy_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
---|---|
Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
Unit 2 | |
---|---|
Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |