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| Start date | Title | Description | Topic | |
|---|---|---|---|---|
| ENS 55674 | 22 December 2021 17:45:00 | Loss of Siren System | The following information was provided by the licensee via email: On December 27, 2021, at 1014 EST, a system error in the site's Alert and Notification Siren System was identified, indicating a loss of the siren system affecting a greater than 25% of the emergency planning zone population. Review of the system's data logger indicates the system error has been present within the system since December 22, 2021, at 1245 EST. The fleet's telecommunications department has been contacted and is aware of the issue. In the event that a radiological emergency should occur at the Shearon Harris Nuclear Power Plant, Primary Route Alerting procedures will be put in use by the local jurisdictions. This condition is reportable as a Loss of Emergency Preparedness Capabilities per 10 CFR 50.72(b)(3)(xiii). The NRC Resident, state and local agencies have been notified.
The following information was provided by the Licensee via email: Further troubleshooting efforts identified that the Chatham County EOC Siren Activation Point remained capable of sending an alert signal to the sirens for the duration of the event described above. This ensures siren activation would be performed in a timely manner in the event of a radiological emergency. This Event Notification is therefore retracted, as no loss of emergency preparedness capabilities has occurred. The NRC Resident and local agencies have been notified. Notified R2DO (Miller) | Siren |
| ENS 51601 | 13 December 2015 08:07:00 | Essential Services Chilled Water System Inoperable | This is a non-emergency eight hour notification for a condition that could have prevented fulfillment of a safety function in a system needed to remove decay heat and to mitigate the consequences of an accident. At approximately 0307 EST on December 13, 2015, the 'A' and 'B' trains of the essential services chilled water (ESCW) system were inoperable for a time period of 23 minutes. The 'B' train of the ESCW system was being tested at the time that the 'A' train of the ESCW system became inoperable. The 'B' train of the ESCW system was returned to operable status at approximately 0330 EST and remains operable. The ESCW system provides cooling support functions to remove decay heat and mitigate the consequences of an accident. There were no safety system actuations during this time period and the plant is stable. This condition does not affect the health and safety of the public or station employees. The NRC Resident Inspector has been notified. The 'A' ESCW pump tripped on low lube oil pressure.
Upon further review of the condition, it was determined that the 'A' train of the ESCW system was capable of performing its safety function throughout the time period previously reported, and the 'A' train of the ESCW system was operable. Therefore, there was no loss of safety function. Event notification 51601 is retracted. The NRC Resident Inspector has been informed of this notification retraction. Notified the R2DO (Guthrie). | |
| ENS 51472 | 15 October 2015 19:54:00 | Technical Support Center Ventilation System Out of Service Due to Discovered Condition | This is a non-emergency eight hour notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) as the discovered condition affects the functionality of an emergency response facility. A condition impacting functionality of the TSC Ventilation system was discovered on October 15, 2015 at 1554 EDT. The issue involved a loss of heating capability of the TSC Ventilation system due to failed ventilation system components. The review of the impact of this equipment failure on the habitability of the TSC over the 30 day mission time determined that this condition was reportable as a loss of emergency assessment capability. The repair of the equipment failure is currently being planned. If an emergency is declared requiring TSC activation during the non-functional period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to an alternate location in accordance with applicable site procedures. This condition does not affect the health and safety of the public or station employees. The NRC Resident Inspector has been notified.
Subsequent calculations determined that the loss of heating capability of the TSC Ventilation system did not affect the TSC functionality at the time of discovery or during the 30 day mission time period. Therefore, the TSC remained functional throughout the time in question. The initial 10 CFR 50.72(b)(3)(xiii) report is being retracted. The NRC Resident Inspector has been informed of this notification retraction. Notified the R2DO (Ehrhardt). | Time of Discovery Mission time |
| ENS 48932 | 16 April 2013 20:25:00 | Potential Cable Size and Breaker Mismatch | During investigation of a documentation discrepancy, a potential cable size and breaker mismatch was identified to exist in a non-safety related DC panel. Initial evaluation has shown that the cable may heat and be potentially damaged if exposed to a 'smart' high impedance fault for an extended period. This discovered condition has not been previously analyzed for NFPA (National Fire Protection Association) 805 common enclosure circuit coordination. Fire watches were established as a compensatory measure immediately following identification of the issue on April 8, 2013. An initial review of fire protection analysis was completed on April 16, 2013. Fire watches remain in place until a modification which will restore coordination is complete. The licensee notified the NRC Resident Inspector. * * * RETRACTION FROM JOHN CAVES TO CHARLES TEAL AT 1400 EDT ON 6/4/13 * * * An analysis demonstrated that adjacent cables in the common enclosure would not be damaged, therefore, the condition does not significantly degrade plant safety. The licensee has notified the NRC Resident Inspector. Notified R2DO (McCoy). |