The US Southeast has a lot of nuke plants. Like this:
It is highly unlikely that a direct hit from the most energetic part of a hurricane would affect a nuclear power plant, as they are very well built. I don’t know what major flooding would do for any given plant. I suspect that most or all nuclear power plants in the region are not as well protected from floods ad they need to be, since a typical year now has flooding that no one ever thought would occur commonly. With climate change, 100-year and 500-year floods happen a couple of times a decade in some areas, and the hypercharged hurricanes we now have, with Houston style flooding (see how “Houston” replaces “Biblical” since we no longer have to imagine the epic flooding!), I think we simply don’t know what will happen at nuclear plants affected by three foot rainfalls in their upper catchments.
The biggest and most likely problem with nuclear plans is this. They need to be cooled. Cooling normally happens when they are operating and producing energy. But when the distribution and transmission grids they serve are obliterated, the plants have to shut down since they can’t send electricity out. They then have to cool themselves using alternative fuels. (I’m oversimplifying a great deal here but I assume people will chime in with plenty of distracting details).
Many, perhaps all, nuke plants in the US Southeast have over recent years (since the Fukushima disaster) upgraded their alternate cooling plans, which mainly involves big generators and supplies of liquid fuel for them.
This weekend may be the test of those upgrades.