ENS 46396
ENS Event | |
---|---|
05:04 Nov 5, 2010 | |
Title | Valid Actuation of an Emergency Diesel Generator Following Inadvertent De-Energization of Safety Bus |
Event Description | This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A), an event or condition that resulted in a valid actuation of emergency AC electrical power systems.
At 0104 EDT on November 5, 2010, the plant was in Mode 5 Cold Shutdown in a refueling outage. Maintenance personnel were performing post maintenance testing on the main generator relay panel when the 'B-SB' Safety Bus was inadvertently de-energized, resulting in automatic starting of the 'B-SB' Emergency Diesel Generator. Safety systems responded as expected during the event, and the 'A-SA' Emergency Bus remained operable with power available from both offsite power and the 'A-SA' Emergency Diesel Generator throughout the event. The 'B-SB' Safety Bus was powering shutdown cooling, which was restored using 'B-SB' Residual Heat Removal system at 0107 EDT with the 'B-SB' Emergency Diesel Generator supplying the bus. The testing procedure was not intended to result in the safety bus being de-energized nor automatic start of the Emergency Diesel Generator. Although the specific cause of the safety bus being de-energized is not known at the present time, it appears that it was directly related to the testing being performed. The licensee notified the NRC Resident Inspector. The 'B-SB' Safety Bus has been returned to its normal offsite power source and the 'B-SB' Emergency Diesel Generator secured and returned to standby status. |
Where | |
---|---|
Harris North Carolina (NRC Region 2) | |
Reporting | |
10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
Time - Person (Reporting Time:+1.77 h0.0738 days <br />0.0105 weeks <br />0.00242 months <br />) | |
Opened: | John Caves 06:50 Nov 5, 2010 |
NRC Officer: | Bill Huffman |
Last Updated: | Nov 5, 2010 |
46396 - 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 46396\u003C/a\u003E - \u003Ca href=\"/Harris\" title=\"Harris\"\u003EHarris\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EValid Actuation of an Emergency Diesel Generator Following Inadvertent De-Energization of Safety Bus\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 46396 - Harris\n","link":"","lat":35.63344166666667,"lon":-78.95586666666667,"icon":"/w/images/7/75/Duke_Energy_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
---|---|
Reactor critical | Not Critical |
Scram | No |
Before | Cold Shutdown (0 %) |
After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 561902022-10-31T00:57:00031 October 2022 00:57:00
[Table view]10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Actuation - Auxiliary Feedwater System Actuation ENS 561892022-10-30T10:53:00030 October 2022 10:53:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip and Auxiliary Feedwater System Actuation ENS 560752022-08-28T07:29:00028 August 2022 07:29:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip and Auxiliary Feedwater System Actuation ENS 558682022-04-29T08:05:00029 April 2022 08:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip and Auxiliary Feedwater System Actuation ENS 533182018-04-07T08:51:0007 April 2018 08:51:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of Auxiliary Feedwater System (Afw) ENS 523352016-10-26T15:42:00026 October 2016 15:42:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Containment Sump Suction Valve Opened During Containment Spray Pump Testing ENS 522912016-10-08T17:28:0008 October 2016 17:28:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Unusual Event Declared Due to Loss of Offsite Power ENS 522892016-10-08T05:50:0008 October 2016 05:50:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Unplanned Reactor Trip and Safety Injection Due to Turbine Control Valve Transient ENS 497422014-01-18T15:16:00018 January 2014 15:16:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Alert Declared Due to Fire in 480V Bus ENS 463962010-11-05T05:04:0005 November 2010 05:04:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Valid Actuation of an Emergency Diesel Generator Following Inadvertent De-Energization of Safety Bus ENS 444232008-08-19T13:05:00019 August 2008 13:05:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rod Control System Malfunctioned ENS 436762007-09-29T02:32:00029 September 2007 02:32:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Loss of a Startup Transformer ENS 428482006-09-19T14:00:00019 September 2006 14:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Generator Lockout Signal ENS 416542005-05-01T04:21:0001 May 2005 04:21:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Loss of Condensate Pump ENS 411792004-11-07T21:35:0007 November 2004 21:35:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation "a" Auxiliary Feedwater (Afw) Pump Manually Started Due to Decreasing Steam Generator Water Level. ENS 411292004-10-18T11:41:00018 October 2004 11:41:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Emergency Diesel Start ENS 407302004-05-06T16:52:0006 May 2004 16:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip and Actuation of Auxiliary Feedwater System ENS 400842003-08-17T19:51:00017 August 2003 19:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Loss of "a" Condensate Pump. 2022-08-28T07:29:00 | |