ENS Event | |
|---|---|
07:24 Jan 7, 2021 | |
| Title | Unusual Event Declared Due to Rise in Drywell Unidentified Reactor Coolant System Leakage |
| Event Description | An Unusual Event was declared at Grand Gulf Nuclear Station at 0124 [CST] on 01/07/2021 due to Unidentified Drywell Leakage exceeding 10 GPM for 15 minutes. Unidentified leakage has reduced to less than 0.44 GPM as of 0213 CST on 01/07/2021.
The cause of the increase leakage rate is under investigation. The licensee notified the NRC Resident Inspector. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
At 0356 CST, Grand Gulf Nuclear Station terminated the Unusual Event following plant parameters returning to normal. The current leakage rate is 0.3 gallons per minute and stable. The NRC Resident Inspector has been notified. Notified R4DO (Kozal), IRD MOC (Gott), NRR EO (Felts), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email). |
| Where | |
|---|---|
Grand Gulf  Mississippi (NRC Region 4) | |
| Reporting | |
| Emergency class: | Unusual Event |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration | |
| Time - Person (Reporting Time:+-4.1 h-0.171 days <br />-0.0244 weeks <br />-0.00562 months <br />) | |
| Opened: | Leroy Purdy 03:18 Jan 7, 2021 |
| NRC Officer: | Brian Lin |
| Last Updated: | Jan 7, 2021 |
| 55056 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 550562021-01-07T07:24:0007 January 2021 07:24:00
[Table view]10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Rise in Drywell Unidentified Reactor Coolant System Leakage ENS 511372015-06-08T03:59:0008 June 2015 03:59:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event - Fire in Protected Area Lasting Greater than 15 Minutes ENS 491362013-06-19T19:10:00019 June 2013 19:10:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Co2 Release in the Auxiliary Building ENS 490252013-05-12T22:43:00012 May 2013 22:43:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to Fire on Auxiliary Transformer Inside Protected the Area ENS 478252012-04-11T23:26:00011 April 2012 23:26:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to a Fire in the 'A' Main Condenser ENS 446622008-11-17T15:25:00017 November 2008 15:25:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Fire in Protected Area Lasting Greater than 15 Minutes 2021-01-07T07:24:00 | |