ENS 51321
ENS Event | |
|---|---|
14:00 Aug 3, 2015 | |
| Title | Loss of Sirens Due to Loss of Power |
| Event Description | On August 14, 2015, the Grand Gulf Nuclear Station (GGNS) determined that less than 75% of the population in the ten mile EPZ could have been notified using the alert notification system (sirens). This condition existed between the time period starting sometime after 1800 [CDT] on Friday, July 31, 2015 until 1630 [CDT] on Monday August 3, 2015.
The completion of this notification was delayed because at the time of discovery the available information and built in system redundancy supported a conclusion that greater than 75% of the population could have been notified using the siren system. The diversity of the systems required repairs and testing to be coordinated with local officials in both Mississippi and Louisiana. At 1000 CDT hours on August 3, 2015, GGNS was informed that the Claiborne County Emergency Operations Center (EOC) siren activation equipment had lost power over the weekend. Investigations and repairs were initiated by Claiborne County Emergency management upon discovery. The system was repaired and functional at 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br /> on August 3, 2015. The licensee reported that 30 of 42 sirens lost power. The NRC Resident Inspector has been notified.
Based on a detailed investigation (an apparent cause evaluation performed by the Grand Gulf Nuclear Station) into the events surrounding the power interruption at the Claiborne County EOC, Entergy has determined that the emergency power source for the Claiborne County EOC was available and would have been manually established by the Claiborne County EOC Emergency Director if the facility was activated. Upon discovery of the problem, maintenance was immediately performed on the system to reestablish the normal source of power to the Claiborne County EOC. This maintenance required approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to complete. This maintenance activity required the lock-out tag-out of all power (normal and back-up) to the facility. During the time period that all power was removed from the facility, the pre-established and pre-approved back-up notification system was available and would have been utilized to complete the required public notifications. Supplement 1 to Revision 3 of NUREG-1022, Event Reporting Guidelines, 10CFR50.72(b)(3)(xiii), states in part the following: NEI 13-01 proposes that for extended unplanned losses of the primary public alerting system, a report would not be required if the FEMA approved backup alerting method was available and the primary public alerting system was returned to service within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> This 24-hour cap is put into place to limit reliance on a less capable backup alerting method. However, because some backup capability exists, NRC action or awareness is not likely warranted in such scenarios for which the loss of the primary capability is limited in duration. As a result, a report would not be required Therefore, Entergy is updating the above notification based on the developed information that the Claiborne County EOC Emergency Director understood how and would have manually established electrical power to the alert notification system if required and because the maintenance period was less than the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowable period established in Supplement 1 to Revision 3 of NUREG-1022. The licensee has notified the NRC Resident Inspector. Notified R4DO (Pick). |
| Where | |
|---|---|
Grand Gulf  Mississippi (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
| Time - Person (Reporting Time:+268.15 h11.173 days <br />1.596 weeks <br />0.367 months <br />) | |
| Opened: | Keith Huff 18:09 Aug 14, 2015 |
| NRC Officer: | Jeff Herrera |
| Last Updated: | Sep 23, 2015 |
| 51321 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 529212017-08-23T08:40:00023 August 2017 08:40:00
[Table view]10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Offsite Telephone Lines ENS 513212015-08-03T14:00:0003 August 2015 14:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Sirens Due to Loss of Power ENS 450362009-05-02T05:02:0002 May 2009 05:02:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Operations Facility Power Interruption ENS 436802007-10-02T03:20:0002 October 2007 03:20:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Exhaust Ventilation Stack Flow and Accident Radiation Monitors Due to Plant Data Multiplexer Failure ENS 436192007-09-06T21:05:0006 September 2007 21:05:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Eof Declared Non-Operational ENS 429402006-10-27T14:15:00027 October 2006 14:15:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Operations Facility Non Operational Due to Planned Maintenance ENS 420112005-09-25T02:21:00025 September 2005 02:21:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Weather Related Loss of Emergency Sirens ENS 419612005-08-29T22:45:00029 August 2005 22:45:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Response Data System (Erds) Was Out of Service for Approximately 20 Minutes ENS 419592005-08-29T17:18:00029 August 2005 17:18:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Partial Loss of Emergency Sirens Associated with Hurricane Katrina ENS 408132004-06-14T11:26:00014 June 2004 11:26:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Failed Data Server for Emergency Response Data System ENS 401102003-08-28T12:50:00028 August 2003 12:50:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Power to Emergency Operations Facility 2017-08-23T08:40:00 | |