ENS 54812
ENS Event | |
|---|---|
03:12 Aug 4, 2020 | |
| Title | Unusual Event Declared Due to a Loss of Offsite Power |
| Event Description | At 2312 EDT, on August 4, 2020, Brunswick Unit 1 declared an Unusual Event due to a loss of offsite power. The unit was at approximately 20 percent power and was not synced to the grid when the unit automatically scrammed. All control rods fully inserted. Emergency Diesel Generators started and began powering the safety buses. Safety systems actuated as expected.
The Unit also experienced a loss of Fuel Pool Cooling and Cleanup System, but one pump was returned to service. Unit 2 remains at 100 percent power and is unaffected. The licensee notified State and local governments, as well as the NRC Resident Inspector. Notified DHS SWO, FEMA Operations Center, CISA IOCC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
At approximately 2302 EDT, a loss of offsite power occurred on Unit 1. This resulted in a Reactor Protection System (RPS) actuation. Per design, emergency diesel generators 1 and 2 properly started and loaded to their respective emergency buses. The Reactor Core Isolation Cooling (RCIC) system was manually started and is being used to control reactor water level. The High Pressure Coolant Injection (HPCI) system was manually started and is being used for pressure control. As previously reported, an Unusual Event was declared at 2312 EDT due to the loss of offsite power. At the time of the event, Unit 1 was in the process of shutting down for maintenance associated with a ground on the main generator. Due to the RPS actuation while critical, this event is being reported as a four-hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B). As a result of the reactor trip, reactor water level reached low level 1 (LL1). The LL1 signal causes a Group 2 (i.e., floor and equipment drain isolation valves), Group 6 (i.e., monitoring and sample isolation valves) and Group 8 (i.e., shutdown cooling isolation valves) isolations. The LL1 isolations occurred as designed; the Group 8 valves were closed at the time of the event. Per design, the loss of offsite power also caused a Group 1 (i.e., main steam isolation valve) isolations. Due to the Emergency Diesel Generator and Primary Containment Isolation System (PCIS) actuations, this event is also being reported as an eight-hour, nonemergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A). Unit 2 was not affected. There was no impact to the health and safety of the public or plant personnel. The safety significance of the event is minimal. All safety related systems operated as designed. Investigation of the cause of the loss of offsite power is in progress. The licensee notified the NRC Resident Inspector. Notified R2DO (Inverso). |
| Where | |
|---|---|
Brunswick  North Carolina (NRC Region 2) | |
| Reporting | |
| Emergency class: | Unusual Event |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+-3.68 h-0.153 days <br />-0.0219 weeks <br />-0.00504 months <br />) | |
| Opened: | Benjamin Williams 23:31 Aug 3, 2020 |
| NRC Officer: | Bethany Cecere |
| Last Updated: | Aug 4, 2020 |
| 54812 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (20 %) |
| After | Hot Shutdown (0 %) |
WEEKMONTHYEARENS 567972023-10-16T02:56:00016 October 2023 02:56:00
[Table view]10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to Fire Not Verified to Be Extinguished within 15 Minutes ENS 548122020-08-04T03:12:0004 August 2020 03:12:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to a Loss of Offsite Power ENS 540522019-05-07T02:04:0007 May 2019 02:04:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Noue Due to Fire Lasting Longer than 15 Minutes in Turbine Building ENS 539612019-03-28T18:50:00028 March 2019 18:50:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unusual Event Declared Due to Rcs Unidentified Leakage ENS 536092018-09-15T04:00:00015 September 2018 04:00:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration En Revision Imported Date 9/19/2018 ENS 520822016-07-13T00:39:00013 July 2016 00:39:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Alert Declared for a Fire in the Service Water Building ENS 517152016-02-07T18:26:0007 February 2016 18:26:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Scram and Alert Declaration Due to Electrical Fault Resulting in Fire/Explosion ENS 507512015-01-22T23:13:00022 January 2015 23:13:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Notification of Unusual Event Declared Due to Toxic Gas in the Security Diesel Building ENS 503552014-08-12T08:32:00012 August 2014 08:32:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Unusual Event for a Halon Release Near the Tsc and Eof ENS 497882014-02-03T15:03:0003 February 2014 15:03:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Toxic Gas Release That Could Affect Normal Operation ENS 497132014-01-11T00:48:00011 January 2014 00:48:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Explosion within Protected Area Boundary ENS 488902013-04-05T10:24:0005 April 2013 10:24:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to a Fire Alarm in the Stack Filter House ENS 487832013-02-26T14:00:00026 February 2013 14:00:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Toxic Gas Leak ENS 474442011-11-16T08:01:00016 November 2011 08:01:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to Drywell Leakage Greater than 10 Gpm ENS 468732011-05-23T19:35:00023 May 2011 19:35:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Alert Declared Due to Halon Discharge in Emergency Diesel Generator Building ENS 459802010-06-06T15:37:0006 June 2010 15:37:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Brunswick Declared Alert Due to Halon Discharge in Emergency Diesel Generator Building ENS 457962010-03-27T02:45:00027 March 2010 02:45:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Dut to Fire Greater than 15 Minutes in Turbine Building ENS 457112010-02-19T16:11:00019 February 2010 16:11:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unsual Event Due to Carbon Dioxide Discharge in the High Pressure Coolant Injection (Hpci) Room ENS 429552006-11-01T23:37:0001 November 2006 23:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Unit 2 Declared an Unusual Event Due to Loss of Offsite Power to the 4Kv Emergency Buses ENS 419832005-09-13T03:14:00013 September 2005 03:14:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Hurricane Ophelia Warning ENS 409532004-08-14T17:08:00014 August 2004 17:08:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Notice of Unusual Event Emergency Declared Due to Loss of Offsite Power ENS 409512004-08-13T22:20:00013 August 2004 22:20:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Notice of Unusual Event Declared Due to Hurricane Warning ENS 401642003-09-17T02:40:00017 September 2003 02:40:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event at Brunswick Due to Hurricane Warning 2023-10-16T02:56:00 | |