If we went nuclear, would there need to be a plant on every county, or a plant in every state? I've not researched this but I've never heard of a nuclear plant that could service like 10-100 homes which to me would be as decentralized as it gets unless you can have 1 per household.
Discussion
You have fourth generation “micro” reactors as small as a few megawatts:
Or you can build gigantic ones where you might only new one or a few per state or anything in between. There’s no scientific limit in that regard. Just a societal choice.