Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 52921 | 23 August 2017 08:40:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Offsite Telephone Lines | At approximately 0340 CDT on Wednesday, August 23, 2017, Grand Gulf Nuclear Station was notified by the Entergy System Dispatcher that the NRC had called them and told them that the NRC could not contact Grand Gulf on the Emergency Notification System (ENS) line nor commercial telephone. Control Room personnel immediately tested several offsite lines including the NRC ENS line and found the lines were non-functional. Offsite prompt Public Warning Sirens were available at all times. State and Local notification capability was available via UHF radio communication. GGN Emergency Response Organization notification capability was available at all times via satellite phone activation of group paging. GGN site Emergency Response Facility intercommunications were available at all times via site internal telephones. In-plant and offsite team communications were available at all times via UHF radio. This event is being reported (8-hour notification) as an event or condition that adversely impacted offsite communications in accordance with 10 CFR 50.72(b)(3)(xiii), specifically the loss of the NRC Emergency Notification System (ENS). The phone company has been contacted and actions are being taken to restore normal communications capability at this time. The NRC Resident Inspector has been notified.
At 1701 EDT on 8/23/17 the phone systems at Grand Gulf have been restored. The licensee will be notifying the NRC Resident Inspector. Notified the R4DO (Farnholtz) | ||
| ENS 51321 | 3 August 2015 14:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Sirens Due to Loss of Power | 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 hours 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 hours 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 hours 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 hour allowable period established in Supplement 1 to Revision 3 of NUREG-1022. The licensee has notified the NRC Resident Inspector. Notified R4DO (Pick). | ||
| ENS 45036 | 2 May 2009 05:02:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Emergency Operations Facility Power Interruption | The Emergency Operations Facility lost power due to a fault on the site power loop. The licensee has not been able to restore power to the facility. The emergency generator also failed to operate. This call is required due to not being able to promptly restore the facility in the event of an accident as noted in NUREG 1022 Section 3.2.13. Maintenance is ongoing. The backup EOF is available and the EOF team will be notified. The licensee notified the NRC Resident Inspector. | ||
| ENS 43680 | 2 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 | On 10/01/2007 the failure of a plant data multiplexer (MUX) resulted in the loss of Control Room indication of all plant building exhaust ventilation stack flows and accident radiation monitors. The stack flows and accident radiation monitors are normally accessed by the plants Emergency Response Organization offsite dose calculation application but cannot be accessed at this time. Alternate means of offsite dose projections are available. The duration of the plant data MUX outage is currently unknown. Follow-up notification will be made after restoration of the plant data MUX. The cause of the failure is being investigated. The licensee notified the NRC Resident Inspector.
The licensee reports that the plant data multiplexer (MUX) has been returned to service. A faulty off-gas building channel (Offgas / Radwaste Building AXM/SPING/FMIS) was the cause of the MUX failure. The off-gas channel remains out of service. The licensee notified the NRC Resident Inspector. R4DO (Nease) notified. | ||
| ENS 43619 | 6 September 2007 21:05:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Eof Declared Non-Operational | On 9/06/2007 a leak in the water supply to the Emergency Operations Facility (EOF) at Grand Gulf Nuclear Station progressed to the point that the facility is not operational. The duration of the water outage is currently unknown. Plant emergency response personnel, state, and local agencies are being informed to use the EOF backup facility." The licensee has notified State and local authorities and the NRC Resident Inspector.
The water supply to the EOF has been repaired and normal water service has been restored. The licensee declared the EOF operable at 1515 CDT on 9/7/07. R4DO (Pruett) has been notified. | ||
| ENS 42940 | 27 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 | The Emergency Operations Facility (EOF) became non operational on October 27, 2006, at 0915 due to planned maintenance on the electrical power distribution for that facility. This call is required due to not being able to promptly restore the facility in the event of an accident as noted in NUREG 1022 Section 3.2.13. The maintenance should be completed by October 28, 2006. The backup EOF will be used during this maintenance. The licensee notified the NRC Resident Inspector. | ||
| ENS 42011 | 25 September 2005 02:21:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Weather Related Loss of Emergency Sirens | Due to weather from Hurricane Rita, 15 of the 43 emergency sirens are inoperable. This places the number of required sirens less than the required operability rate of 75%. A recovery effort is in progress. Alternate notification methods with LLEA (state and local governments) are being set up. The licensee expects to return the sirens to service by tomorrow. The licensee notified the NRC Resident Inspector. | ||
| ENS 41961 | 29 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 | The licensee's ERDS was unavailable for 20 minutes. After another attempt was made to activate ERDS, it was successful when the phone modem was cycled and the connection was established. The NRC resident Inspector was notified.. | Emergency Response Data System | |
| ENS 41959 | 29 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 | Due to winds associated with hurricane Katrina, power has been loss to 17 of the 43 emergency sirens. This places the number of required sirens less than the operability rate of 75%. Additional sirens may be lost as the storm passes through the area. A recovery plan will be developed and implemented once weather conditions allow. Notification per ENS (the Emergency Notification System) could not be accomplished and notification was made per commercial phone lines. This event notification documents loss of ENS also which was verified by NRC. The licensee has notified State and local authorities and the NRC Resident Inspector of this event. | ||
| ENS 40813 | 14 June 2004 11:26:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Failed Data Server for Emergency Response Data System | At 0626 (CST) on June 14, 2004; the Plant Data System (PDS) data server for the NRC Emergency Response Data System (ERDS) link was found to have failed at 0204 on June 11, 2004. The data server was rebooted, PDS software initiated and ERDS capability restored at 0745 on 6/14/04. Total time out of service was 3 days, 5 hours and 41 minutes. The licensee will notify the NRC Resident Inspector. | Emergency Response Data System | |
| ENS 40110 | 28 August 2003 12:50:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Power to Emergency Operations Facility | The Emergency Operations Facility (EOF) for Grand Gulf was lost when power was removed from the facility and the EOF diesel generator failed to start. Power had to be removed due to the loss of one phase of the local power supply. Actual plant operations are not affected. The power phase problem and failure of the EOF diesel generator to start are being investigated at this time. The Backup EOF is available if needed. The licensee notified the NRC Resident Inspector.
As of 09/02/03, power to the Grand Gulf Emergency Operations Facility (EOF) has been restored. The NRC Resident Inspector will be notified. Notified R4DO Charles Marschall. |