If you have a site that's approved for a nuclear power, there is overhead in getting that approval, but once you have a site you can roll through multiple reactors.

It's similar to the housing crisis: all this talk about pre-built components to make building homes/mid-rises/etc faster ignores all the planning approval and NIMBY objections that need to be ploughed through first.

not that many either if the design is sufficiently flexible. That's how japan spewed several ABWR's so fast