ENS 51557
ENS Event | |
|---|---|
13:23 Nov 20, 2015 | |
| Title | Inoperable Vent Stack Radiation Monitor |
| Event Description | At 0823 EST on 11/17/2015, the Unit 1 'A' Vent Stack radiation monitor, 1-VG-RI-179, was declared non-functional due to a faulty heat trace circuit. Compensatory measure to perform grab samples every 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> was implemented. At 0823 EST on 11/20/2015, the Unit 1 'A' Vent Stack radiation monitor, 1-VG-RI-179, had been out-of-service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The loss of 1-VG-RI-179 is being reported per 10 CFR 50.72(b)(3)(xiii) as a loss of emergency assessment capability. Corrective actions continue to be pursued to restore 1-VG-Ri-179 to functional status.
The NRC Senior Resident Inspector has been notified by the licensee.
The Unit 1 'A' Vent Stack radiation monitor, 1-VG-RI-179, was returned to service at 1440 EST on 11/21/15. The licensee has notified the NRC Resident Inspector. Notified R2DO (Ernstes).
The purpose of this report is to retract the event notification report made in accordance with 10 CFR 50.72(b)(3)(xiii) on November 20, 2015 at 1534 EST (EN 51557). After further review it has been determined that the performance of grab samples is an approved back-up method for radiological assessment capabilities as described in the North Anna Emergency Plan implementing procedure EPIP-4.24 Gaseous Effluent Sampling During Emergency. During non-emergencies, VPAP-2103N Offsite Dose Calculation Manual governs grab sampling and is tracked by Operations using 1-LOG-14 Non-Routine Surveillance Log. As such, a loss of radiological assessment capability did not exist and the ability to assess EAL RU1.4 was not affected. This is consistent with NUREG 1022, Rev.3, Supplement 1 and NEI 13-01, Rev. 0. The action was cleared at 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br /> on 11/21/15 and the Unit 1 'A' Vent Stack radiation monitor, 1-VG-RI-179, was returned to functional status. The NRC Senior Resident lnspector has been informed of this event notification retraction. Notified R2DO (Masters). |
| Where | |
|---|---|
North Anna  Virginia (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
| Time - Person (Reporting Time:+2.18 h0.0908 days <br />0.013 weeks <br />0.00299 months <br />) | |
| Opened: | Michael Whalen 15:34 Nov 20, 2015 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Jan 11, 2016 |
| 51557 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 575532025-02-18T05:05:00018 February 2025 05:05:00
[Table view]10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Communication Capability ENS 515572015-11-20T13:23:00020 November 2015 13:23:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Inoperable Vent Stack Radiation Monitor ENS 496722013-12-23T13:23:00023 December 2013 13:23:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Communications with Virginia State Eoc Due to Power Outage ENS 467512011-04-14T08:00:00014 April 2011 08:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Ventilation System Out of Service for Maintenance ENS 466762011-03-15T15:31:00015 March 2011 15:31:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Power to Technical Support Center Ventilation System ENS 460392010-06-23T13:10:00023 June 2010 13:10:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Early Warning Siren Test Failure ENS 460132010-06-16T12:59:00016 June 2010 12:59:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Early Warning System Found Non-Responsive During Testing ENS 435462007-08-03T12:55:0003 August 2007 12:55:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Safety Parameter Display System (Spds) Out of Service ENS 424432006-03-22T17:51:00022 March 2006 17:51:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Potential Loss of Communication Sirens ENS 420972005-10-30T05:50:00030 October 2005 05:50:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Spds Unavailable for Greater than One Hour ENS 419002005-08-07T04:00:0007 August 2005 04:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Spds Unavailable for Greater than One Hour ENS 414562005-03-02T17:39:0002 March 2005 17:39:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Sirens ENS 414262005-02-21T07:50:00021 February 2005 07:50:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Safety Parameter Display System Inoperable for Greater than One Hour ENS 408202004-06-16T13:45:00016 June 2004 13:45:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Assessment Capability ENS 401792003-09-19T13:30:00019 September 2003 13:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Siren Capability to the Adverse Weather Conditions 2025-02-18T05:05:00 | |