ENS 56809
ENS Event | |
|---|---|
13:07 Oct 21, 2023 | |
| Title | Notification of Unusual Event Declared |
| Event Description | The following information was provided by the licensee via fax and email:
Fire potentially degrading the level of safety of the plant. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: At 0907 EST, the licensee declared a notification of unusual event, under emergency action level HU.4, due to multiple fire alarms and CO2 discharge in the emergency diesel building. When the plant fire brigade entered the building, there was no indication of fire or damage to any plant equipment. The cause of the multiple alarms is under investigation. State and local authorities were notified and no offsite assistance was requested. Both units remain at 100 percent power. The NRC Resident Inspector has been notified. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).
At 1007 EDT, Watts Bar terminated the notification of unusual event. The basis for termination was that no fire or damaged plant equipment was found. The NRC Resident Inspector has been notified. Notified R2DO (Miller), IR-MOC (Crouch), NRR-EO (Felts), DHS-SWO, FEMA Ops Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).
Watts Bar Nuclear Plant (WBN) is retracting Event Notice 56809, Notice of Unusual Event, based on the following additional information, not available at the time of the initial notification. Specifically, in accordance with the emergency preparedness implementing procedures, WBN reported a condition that was determined to meet emergency action level (EAL) HU4, Initiating criteria number 1, receipt of multiple (more than 1) fire alarms or indicators and the fire was within any Table H2 plant area, which includes the diesel generator building. It was further determined that multiple fire detection zones actuated (spurious and invalid) enabling the discharge of installed fire suppression (CO2) into the space. Upon entry by the site fire brigade, it was determined that no smoke or fire existed and reported to the Shift Manager at 0930 EDT. All fire alarms were reset. Troubleshooting activities are in progress to determine the cause. A fire watch has been established and CO2 has been isolated. The required compensatory measures for the affected areas will remain in place until completion of the investigation, and CO2 suppression is restored to functional. Notified R2DO (Miller), IR-MOC (Crouch), NRR-EO (Felts), DHS-SWO (email), FEMA Ops Center (email), CISA Central (email), FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email). |
| Where | |
|---|---|
Watts Bar  Tennessee (NRC Region 2) | |
| Reporting | |
| Emergency class: | Unusual Event |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration | |
| Time - Person (Reporting Time:+-3.7 h-0.154 days <br />-0.022 weeks <br />-0.00507 months <br />) | |
| Opened: | Tyson Jones 09:25 Oct 21, 2023 |
| NRC Officer: | Karen Cotton-Gross |
| Last Updated: | Oct 22, 2023 |
| 56809 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 568092023-10-21T13:07:00021 October 2023 13:07:00
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