I don't know much about nuclear plan, but I doubt UK are much safer in practice than French ones, or even Korean/Japanese ones. I suspect most of the cost difference across countries of similar development to be mostly regulation. And it is a nice example that sometimes EU can be better than the US at regulations :) (I don't know how much nuclear-related regulations are EU vs nation-based though).
E.g. according to https://www.samdumitriu.com/p/infrastructure-costs-nuclear-e..., UK/US is ~10 millions GBP, France ~4.5, and China/Korea/Japan around 2.5.
I don't know much about nuclear plan, but I doubt UK are much safer in practice than French ones, or even Korean/Japanese ones. I suspect most of the cost difference across countries of similar development to be mostly regulation. And it is a nice example that sometimes EU can be better than the US at regulations :) (I don't know how much nuclear-related regulations are EU vs nation-based though).