The problem is the economics. They’re just horrifyingly expensive to build. The equivalent to each new large scale reactor in GWe requires tens of billions in subsidies.

The next problem comes from incentives. Why should anyone with solar or storage buy this expensive grid based nuclear electricity?

Why should their neighbors not buy surplus renewables and instead pay out of their nose for expensive nuclear powered electricity?

EDF is already crying about renewables cratering the earning potential and increasing maintenance costs for the existing french nuclear fleet. Let alone the horrifyingly expensive new builds.

And that is France which has been actively shielding its inflexible aging nuclear fleet from renewable competition, and it still leaks in on pure economics.