ENS 50881
ENS Event | |
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14:00 Mar 12, 2015 | |
Title | Loss Of The Seismic Monitoring Computer |
Event Description | In accordance with 10 CFR 50.72(b)(3)(xiii), this notification reports a loss of Emergency Preparedness assessment capability with the unplanned inoperable condition for the Byron seismic monitor. Specifically, the seismic monitor was declared non-functional at 0345 CST on March 7, 2015 following an unplanned loss of the seismic monitoring central computer. This condition adversely impacted the capability to perform an ALERT EAL (HA4) assessment in accordance with the Radiological Emergency Plan Annex. The loss of assessment capability is reportable to the NRC within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the discovery in accordance with 10 CFR 50.72(b)(3)(xiii)
The seismic recorder was reset by Plant Engineering at 0440 CST on March 8 2015, which restored the seismic monitoring system to full capability. The unplanned non-functional condition of the seismic monitor was entered into the Byron CAP [Corrective Action] Program when the condition was discovered. Initially it was determined that the condition did not meet the requirements for an ENS notification as it was concluded that it did not substantially impair Byron station's emergency assessment capability in the event of an earthquake. Upon further review, at 0900 CDT on March 12, 2015, it was concluded that an ENS notification was warranted because the monitor was specifically Cited in the Emergency Action Level (EAL) HA4 threshold for identifying an ALERT due to an OBE (Reference procedure EP-AA-1002, Addendum 3, 'Emergency Action Levels for Byron Station'). A follow-up written notification is not required for this notification under 10 CFR 50.73. The NRC Resident Inspector has been notified." The State of Illinois Resident Inspector has been notified.
Upon further review of this event for the time period of 3/07/12 through 3/17/15, Byron Station has identified six previous occurrences where the Seismic Monitor was declared non-functional, which impacted the capability to perform an ALERT EAL (HA4) assessment in accordance with the Radiological Emergency Plan Annex. These occurred on November 6, 2014; April17, 2013; January 2, 2013; October 10, 2012; July 18, 2012 and July 9, 2012. The NRC Resident Inspector has been notified. Notified the R3DO (Roach). |
Where | |
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Byron Illinois (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
Time - Person (Reporting Time:+2.1 h0.0875 days <br />0.0125 weeks <br />0.00288 months <br />) | |
Opened: | Shane Harvey 16:06 Mar 12, 2015 |
NRC Officer: | Daniel Mills |
Last Updated: | Mar 19, 2015 |
50881 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
WEEKMONTHYEARENS 566982023-08-25T21:00:00025 August 2023 21:00:00
[Table view]10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Assessment Capability ENS 563542023-02-06T11:30:0006 February 2023 11:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Communications and Assessment Capabilities ENS 557692022-03-06T03:15:0006 March 2022 03:15:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Degradation of Technical Support Center ENS 547102020-05-13T15:00:00013 May 2020 15:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Response Facility ENS 529192017-08-21T02:08:00021 August 2017 02:08:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Assessment Capability Due to Non-Functional Tsc Ventilation ENS 521002016-07-18T20:00:00018 July 2016 20:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Offsite Communications Capability ENS 514122015-09-17T05:30:00017 September 2015 05:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Control Room Area Radiation Monitors Not Able to Provide Radiation Level Information ENS 514012015-09-17T03:00:00017 September 2015 03:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Seismic Monitoring Instrumentation During Planned Maintenance ENS 509882015-04-16T10:00:00016 April 2015 10:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Scheduled Maintenance Affecting Technical Support Center Hvac ENS 508812015-03-12T14:00:00012 March 2015 14:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of the Seismic Monitoring Computer ENS 495992013-12-03T04:00:0003 December 2013 04:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center (Tsc) Non-Functional Due to Planned Maintenance ENS 493752013-09-21T20:31:00021 September 2013 20:31:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Commercial and Ens Communications Due to an Area Phone Outage ENS 491382013-06-20T16:18:00020 June 2013 16:18:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Ventilation Removed from Service for Maintenance ENS 482902012-09-10T14:00:00010 September 2012 14:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Plant Process Computer Removed from Service for Maintenance ENS 472772011-09-19T15:07:00019 September 2011 15:07:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Spds and Erds Unavailable During Replacement of Plant Process Computer System ENS 459982010-06-10T13:30:00010 June 2010 13:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Ventilation Maintenance ENS 459712010-06-01T17:39:0001 June 2010 17:39:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Ventilation System Discovered to Be Non-Functional ENS 450572009-05-12T07:44:00012 May 2009 07:44:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Assessment Capability ENS 450202009-04-25T15:48:00025 April 2009 15:48:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Erds Unavailability Due to Plant Process Computer Failure ENS 449012009-03-12T09:20:00012 March 2009 09:20:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Process Computer and Erds Unavailable for Greater than 60 Minutes ENS 443842008-08-04T23:45:0004 August 2008 23:45:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of 84 of 94 Emergency Sirens Due to Inclement Weather ENS 427122006-07-18T02:46:00018 July 2006 02:46:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Evacuation Siren Failures Due to Thunderstorms 2023-08-25T21:00:00 | |