Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 56088 | 4 September 2022 23:39:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Security Event - Unauthorized Individual in Owner Controlled Area | At 1939 EDT, the North Anna Power Station Units 1/2 declared a Notice of Unusual Event (NOUE) under emergency declaration HU1.1 confirmed security event. Both units were unaffected by the event. The licensee exited the NOUE at 2036 EDT. | ||
| ENS 53909 | 3 March 2019 14:16:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notice of Unusual Event Due to Unconfirmed Fire Alarm | At 0916 EST on March 3, 2019, North Anna Unit 2 declared a Notice of Unusual Event under Emergency Action Level HU 2.1 (fire in/or restricting access to any table H-1 area not extinguished within 15 minutes of control room notification or verification of a control room alarm). At 0906 the control room received a heat sensor alarm for the Unit 2, Reactor Coolant Pump motor cube. The fire brigade was dispatched to the scene where they found no indication of fire, no smoke and no fire damage. There were no actuations associated with the alarm and no redundant indications of fire. There was no effect on plant equipment and no indications of RCS leaks. The site determined that the alarm was invalid and terminated the NOUE. Unit 2 is in a stable condition and in a normal electrical lineup. Offsite support was not requested. The NRC Resident Inspector, State, and local authorities have been notified by the licensee. Notified R2RA (Haney), DNRR (Evans), IRD MOC (Grant), R4RDO (Rose), DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email). | ||
| ENS 47769 | 26 March 2012 03:36:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to Seismic Activity | On March 25, 2012 at 2336 EDT, an Unusual Event was declared due to an earthquake felt on site. The site entered EAL HU1.1. No plant systems were affected. The National Earthquake Information Center reported a magnitude 3.1 seismic event 6 miles south-south west of Mineral, Virginia. A plant inspection is on-going to determine any plant issues related to the seismic event. Unit 1 is in a refueling outage and containment integrity was maintained. Unit 2 continues in full power operation. The licensee notified the NRC Resident Inspector, State and local agencies. Notified DHS SWO, FEMA, NICC and Nuclear SSA via email.
On March 26, 2012 at 0410 EDT, the Unusual Event was terminated. The basis for the termination was that all equipment walkdowns are complete with no damage discovered. The licensee will notify the NRC Resident Inspector. Notified the R2DO (Haag), NRR EO (Brown), IRD (Grant), DHS SWO, FEMA, NICC and the Nuclear SSA via email. | ||
| ENS 47626 | 30 January 2012 23:56:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to an Earthquake of Magnitude 3.2 | At 1856 EST, North Anna, Units 1 and 2, experienced an onsite seismic event. This was confirmed by the National Earthquake Information Center to be a magnitude 3.2. Based on these 2 indications the licensee declared an Unusual Event per EAL HU 1.1. The earthquake did not impact operations or equipment, and both units remain at 100% power. To exit the Unusual Event the licensee will need to verify that no damage was sustained to any systems or equipment. Presently the licensee is conducting a walkdown to verify no damage was incurred. The licensee has notified the NRC Resident Inspector. The licensee also notified the state and other government agencies. * * * UPDATE AT 0048 EST ON 1/31/12 FROM ROGER SMUTHERS TO PETE SNYDER * * * The NOUE declared at 1856 EST on 1/30/12 has been terminated (at 0035 EST). The event has been terminated after completion of AP-36, which is the procedure used when seismic activity is experienced. The abnormal procedure included engineering and operations inspections of various systems throughout the station, all of which were completed satisfactorily with no damage found relating to the seismic event. None of the stations seismic instrumentation actuated during the event due to low seismic activity felt at the station. The newly installed Free Field Seismic Instrumentation did not actuate which has a trigger point of 0.1 g's further demonstrating the low level of the seismic activity experienced at the station. The licensee notified the NRC Resident Inspector. Notified R2DO (Bonser), NRR (Lund), IRD (Grant), DHS (Gates), and FEMA (Biscoe). | ||
| ENS 47228 | 1 September 2011 09:18:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to an Aftershock Earthquake | At 0518 EDT, North Anna Power Station declared an Unusual Event due to seismic activity onsite (EAL HU 1.1). Both units are currently shutdown and electrical power is being supplied from offsite. There were no personnel injuries. There was no radiological release. Site structure and system inspections are in progress. No damage has been identified. The NRC Resident Inspector and state and local authorities have been notified.
The licensee has exited from its unusual event at 1223 EDT on 9/01/11 based on completion of plant walk downs and equipment checks, after the latest 3.4 magnitude earthquake, and no damage noted. The licensee has notified appropriate state and local authorities and will notify the NRC Resident Inspector. Notified R2DO (Sykes) , NRR (King) , IRD (Gott) , FEMA (Blankenship), DHS (Gates) | ||
| ENS 47196 | 25 August 2011 05:18:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to an Aftershock Earthquake | On August 25th at 0118 EDT, North Anna Power Station declared an Unusual Event due to seismic activity onsite (EAL HU 1.1). Both units are currently shutdown and electrical power is being supplied from offsite. There were no personnel injuries. There was no radiological release. Site structure and system inspections are in progress. No damage has been identified. The NRC Resident Inspector and state and local authorities have been notified.
At 1149 EDT another minor tremor was felt at the station. No geological information is available at this time. There is no immediate indication of any equipment damage. Walkdowns are being performed at this time. North Anna Emergency Management indicated that there was currently no plan to secure from the Notification of Unusual Event until there is sufficient indication that the station will not experience any additional aftershocks to prevent having to re-enter an emergency status once exited. The current status of North Anna, Unit 1 is Mode 5. Unit 2 is in Mode 3 in preparation for cool down. The licensee will verify that the NRC Resident Inspector is notified. Notified IRD (Marshall), NRR (Thorp), and R2DO (Widmann).
The licensee has exited from its unusual event at 1536 EDT on 8/28/11 based on the cessation of any further seismic activity. The licensee has notified appropriate state and local authorities and will notify the NRC Resident Inspector. Notified R2DO (Widmann), NRR (Bahadur), IRD (Marshall), FEMA (Vitale) and DHS (Hill). | ||
| ENS 47181 | 23 August 2011 18:03:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Alert Declared Due to an Earthquake in the Area and a Loss of Offsite Power | At 1403 hrs. EDT, North Anna Power Station declared an Alert due to significant seismic activity onsite. The Alert was declared under EAL HA6.1. Both units experienced automatic reactor trips from 100% power and are currently stable in Mode 3. All offsite electrical power to the site was lost. All four emergency diesel generators (EDG) automatically started and loaded and provided power to the emergency buses. While operating, the 2H EDG developed a coolant leak and was shutdown. As a result, the licensee added EAL SA1.1 to their declaration. All control rods inserted into the core. Decay heat is being removed via the steam dumps to atmosphere. No personnel injuries were reported.
The licensee has downgraded the Alert to a Notification of Unusual Event based on equipment alignments and inspection results. The licensee notified R2 IRC. Notified IRD (Marshall), NRR (Thorp), FEMA (Hollis), DHS (Inzer), USDA (Ferezan), HHS (Willis) and DOE (Parsons).
The licensee has exited the Notification of Unusual Event at 1315 EDT. The exit criteria was that all inspections and walkdowns were completed and plant conditions no longer meet the criteria for a NOUE. Notified R2DO (Widmann), IRD (Marshall), NRR (Thorp), FEMA (Hollis), DHS (Inzer), USDA (Ferezan), HHS (Willis) and DOE (Jackson).
This notification is to report new information identified post event that a condition existed which met the emergency plan criteria but was not declared. On August 23 at 1403 EDT, North Anna Power Station declared an Alert due to seismic activity onsite. The Alert was declared under Emergency Action Level (EAL) HA6.1 "Other conditions existing which in the judgment of the SM warrant declaration of an alert. Initial review of seismic response data from the earthquake on 8/23/11 (1348 hours) indicates that design spectrum input assumptions (i.e. Design Basis Earthquake (DBE) limits) may have been exceeded above 5 HZ. This would have resulted in classification of an Alert under EAL HA1.1. No significant equipment damage to safety related systems (including class I structures) has been identified through site walk-downs nor has equipment degradation been detected through plant performance and surveillance testing following the earthquake. The licensee notified the NRC Resident Inspector. The licensee also plans on notifying the State Emergency Operations Center and the Louisa County County Administrator. Notified R2DO (Widmann) and NRR EO (Bahadur). | Emergency Diesel Generator Control Rod | |
| ENS 41104 | 8 October 2004 17:55:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Due to Actuation of Carbon Dioxide Fire Suppression System in Turbine Building | The licensee experienced an apparently spurious actuation of the CO2 (carbon dioxide) suppression system in the North Anna Unit 1 turbine building (specifically the main turbine, low pressure turbine, and exciter area). The licensee responded and determined there was no fire and secured the CO2 release within two minutes. The event was classified as an unusual event per item K.13 of the emergency action levels due to onsite release of a toxic gas. The licensee has pulled the actuation fuses on the system, isolated the CO2 storage tank, and is in the process of ventilating the area. A fire watch has been posted and the licensee is checking CO2 levels throughout the area. There were no injuries as a result of the discharge and no significant operational impairment. The licensee has notified appropriate state and local authorities as required due to the declaration of an unusual event. The licensee will also notify the NRC resident inspector.
The licensee terminated the unusual event at 14:45 EDT following inspection of the turbine building and confirmation that CO2 levels did not represent a personnel hazard. R2DO (Ogle); NRR EO (Reis); NSIR IRD (Wilson); FEMA (Dunker); and the DHS senior watch officer have been notified. | Main Turbine |