ENS 55580
ENS Event | |
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22:28 Nov 15, 2021 | |
Title | Manual Reactor Trip Due to Main Transformer Fault |
Event Description | At 1728 EST on 11/15/2021, with Unit 1 in Mode 1 at 47 percent power, the reactor was manually tripped due to a main transformer fault. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being removed by the emergency feedwater system through the main condenser.
Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Additionally, due to the valid actuation of the emergency feedwater system, this event is being reported as a non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Senior Resident Inspector has been notified."
At approximately 0900 [EST] on 11/16/2021, it was identified that mineral oil from the faulted main transformer had surpassed the capability of the oil containment system and discharged into Lake Monticello. It is estimated that less than 50 gallons of mineral oil entered the Lake. The oil is contained with booms and cleanup is ongoing. The EPA National Response Center and the South Carolina Department of Health and Environmental Control have been notified. This is considered a news release or notification to other government agencies; therefore, this event is reportable under 10 CFR 50.72(b)(2)(xi). The NRC Senior Resident Inspector has been notified. Notified R2DO (Miller). |
Where | |
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Summer South Carolina (NRC Region 2) | |
Reporting | |
10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
Time - Person (Reporting Time:+-1.47 h-0.0613 days <br />-0.00875 weeks <br />-0.00201 months <br />) | |
Opened: | Leon Smith 21:00 Nov 15, 2021 |
NRC Officer: | Donald Norwood |
Last Updated: | Nov 16, 2021 |
55580 - NRC Website | |
Unit 1 | |
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Reactor critical | Critical |
Scram | Yes, Manual Scram |
Before | Power Operation (47 %) |
After | Hot Standby (0 %) |
Summer with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 569782024-02-19T07:36:00019 February 2024 07:36:00
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