I was talking capital costs, not operational costs. My point is, to build a nuclear power plant you essentially need to build a thermal power plant first and then add things for the nuclear part (which is arguably more complicated/safety critical than for e.g. a coal plant).

So the whole argument for economics of scale doesn't work, thermal power plants have not reduced dramatically in price over the last decades despite lots of them being build. Half of your plant not really reducing much in price, will limit the benefits you can get even if the other half sees massive cost reductions.

> I was talking capital costs, not operational costs.

Ok, but surely the only cost that matters is the lifetime cost? (Including whatever cleanup is needed for both nuclear and whichever fossil and/or renewable+storage combination it is compared against).

> Half of your plant not really reducing much in price, will limit the benefits you can get even if the other half sees massive cost reductions.

Sure, absolutely. But coal is pretty expensive over the course of a year, so it can look like a good opportunity (if only for the reality hadn't turned out so fragile and, when it goes wrong, severe).