“At 1812 CDT, Waterford 3 declared a notification of unusual event under EAL S.U. 1.1 due to a loss of offsite power as a result of hurricane Ida. Plant power is being provided via emergency diesel generators. The NRC Activated at 2016 EDT with Region IV in the lead.”
Looks like they had already SCRAM’d the main reactor prior to the hurricane, but even then they need to keep cooling the core for many months before a total shutdown would be safe. In any event, I don’t think they were going for a full shutdown, but only for the duration of the hurricane, which means it was still hot.
They are now running on emergency backup generators to keep the core cool.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/en.html
According to Entergy
Waterford 3 declared an Unusual Event at 6:12 p.m. after losing power from offsite. An NOUE is the least serious of NRC emergency response classifications. Backup diesel generators started as designed and are providing power to the plant, which is stable and secure.
— EntergyNuclear (@EntergyNuclear) August 30, 2021
Nuclear plants are designed to withstand extreme conditions, with steel-reinforced concrete containment structures protecting the reactors and redundant safety systems.
— EntergyNuclear (@EntergyNuclear) August 30, 2021
h/t Beanie Baby