ENS 47138
ENS Event | |
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06:00 Aug 10, 2011 | |
Title | Potential Loss of Tsc Operability While Performing Planned Maintenance |
Event Description | A planned maintenance evolution at the Duane Arnold Energy Center (DAEC) will have the potential to remove the plant computer systems (Plant Process Computer, Intranet, and Internet) from service. The TSC would be rendered non-functional with the loss of all computer systems. The replacement and testing of the automatic power transfer relay is expected to de-energize the computer systems for less than 20 minutes at any time.
If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures. Maintenance will be terminated and power will be restored to the plant computer systems. The restoration of power to all computer systems is estimated to take less than one hour. This notification is being made in accordance with 10CFR50.72 (b)(3)(xiii) due to the potential loss of an Emergency Response Facility (ERF). An update will be provided once the plant computer systems power supplies have been restored to normal operation. The licensee has notified the NRC Resident Inspector.
The TSC has been restored to operational status. The licensee has notified the NRC Resident Inspector. Notified R3DO (Dickson).
The licensee is performing planned maintenance on the TSC automatic power transfer relay which could render the TSC inoperable if power to the TSC computers is lost. Maintenance is expected to commence at 2130 CDT. The licensee has notified the NRC Resident Inspector. Notified R3DO (Peterson). |
Where | |
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Duane Arnold Iowa (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
Time - Person (Reporting Time:+-3.9 h-0.163 days <br />-0.0232 weeks <br />-0.00534 months <br />) | |
Opened: | Jeff Miell 02:06 Aug 10, 2011 |
NRC Officer: | Howie Crouch |
Last Updated: | Aug 12, 2011 |
47138 - NRC Website | |
Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
WEEKMONTHYEARENS 535002018-07-11T05:00:00011 July 2018 05:00:00
[Table view]10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Meteorological Data Unavailable ENS 507432015-01-19T03:31:00019 January 2015 03:31:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Normal Technical Support Center Power ENS 497472014-01-21T04:30:00021 January 2014 04:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Emergency Diesel Generator Out of Service ENS 495572013-11-19T10:20:00019 November 2013 10:20:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Emergency Backup Power Supply Maintenance ENS 494152013-10-07T15:27:0007 October 2013 15:27:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Planned Maintenance Causing Loss of Meteorological Tower Data ENS 493832013-09-25T08:04:00025 September 2013 08:04:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Normal Tsc Power Due to Transformer Isolation ENS 493572013-09-19T09:50:00019 September 2013 09:50:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Emergency Diesel Generator Removed from Service for Planned Maintenance ENS 490922013-06-06T13:00:0006 June 2013 13:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Emergency Power Supply Removed from Service for Planned Maintenance ENS 486482013-01-03T15:30:0003 January 2013 15:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Erds Capability ENS 485102012-11-16T14:10:00016 November 2012 14:10:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Spds Out of Service Due to Planned Maintenance ENS 482962012-09-11T08:08:00011 September 2012 08:08:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Non-Functional Due to Planned Maintenance ENS 482142012-08-21T09:07:00021 August 2012 09:07:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Out of Service ENS 475572011-12-29T15:10:00029 December 2011 15:10:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Planned Maintenance on Plant Process Computer ENS 474902011-11-30T15:35:00030 November 2011 15:35:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Plant Process Computer Out of Service Due to Planned Maintenance ENS 474312011-11-11T16:21:00011 November 2011 16:21:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Inoperable Due to Planned Maintenance ENS 473542011-10-19T15:00:00019 October 2011 15:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Emergency Diesel Non-Functional ENS 473502011-10-18T09:50:00018 October 2011 09:50:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Emergency Diesel Generator Out of Service ENS 472352011-09-01T15:50:0001 September 2011 15:50:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Diesel Generator Non-Functional ENS 471382011-08-10T06:00:00010 August 2011 06:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Potential Loss of Tsc Operability While Performing Planned Maintenance ENS 465422011-01-14T14:40:00014 January 2011 14:40:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Out of Service Due to Maintenance ENS 453402009-09-11T16:01:00011 September 2009 16:01:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Unavailable Due to Maintenance ENS 442912008-06-12T16:30:00012 June 2008 16:30:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Unusual Event Declared Due to a Major Loss of Response and Communications Capability ENS 422992006-02-02T00:55:0002 February 2006 00:55:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Site External Communications ENS 422412006-01-04T17:00:0004 January 2006 17:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Partial Loss of Emergency Sirens ENS 409952004-08-28T06:46:00028 August 2004 06:46:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Failure of the Plant Process Computer Due to Loss of Power Supply 2018-07-11T05:00:00 | |