OldHistoryHamFag reporting.
I have a number of sources in the power industry. I've also been looking at the NC/SC nuke plants on Google Earth. I'm also from the CLT area and know about Duke Power.
It appears that all of the plant's diesel generator buildings are above ground. The problem with Fukishima was that they put the fucking backup generators in the basement next to the fucking ocean.
Nuke plants take many days to cool down once they're in shutdown mode. The cooling pumps need to keep running and this is usually done using power from the grid. The backup generators are meant to keep the cooling and control systems working.
So, in Japan, they had the earthquake and then the tsunami that flooded the generators. When they Fukishima plants lost grid power, they could not go to diesels and thus lost cooling capacity except for some power from the #4 reactor, if memory serves.
I had a discussion about this with a Navy nuke guy who's a whole lot smarter than I am about this stuff. Let us hope that the power companies are doing a good shutdown NOW.