The closest I've gotten to somebody finding environmental regulations that were driving up the cost of nuclear was with some of the latest stuff with people trying to get rid of the LNT model of how radiation affects people.

Getting rid of LNT would allow higher doses to workers, and the way it makes nuclear cheaper is by having less shielding around the reactor.

But if you look at how recent reactors like the AP1000 failed, it's not so much because of the mere quantity of concrete. In fact, one of the big advantages of the AP1000 is that it used a fraction of the concrete and steel of prior designs. The real problem at Vogtle were construction logistics, matching up design to constructible plans, and doing that all in an efficient manner.

The construction process didn't run over budget and over timeline because of environmental regulations, that happened because we don't know how to build big things anymore, in combination with leadership asking for regulatory favors like starting construction before everything has been fully designed, which gave them more rope to hang themselves with.

I don't know the specifics of why France forgot how to build, at Flamanville and Olkiluoto, but I imagine it's a similar tale as in the US. High labor costs, poor logistics, projects dragged out, and having to pay interest on the loan for years and years extra with every delay.

If there's somebody with more specifics on how unnecessary regulation is killing nuclear, I'd love to see it. But after watching attentively and with great interest since ~2005, I've become so disillusioned with nuclear that I doubt we'll ever see it have success in the West again. Factories and manufacturing have seen productivity go through the roof over the past 50 years, while construction productivity is stagnant. Playing to our strengths, and using our very limited construction capacity on building factories rather than building generators, seems far wiser on the macroeconomic scale.