France and Finland have had excessive difficulty with their EPR.

My hypothesis is that modern economies with high wages will simply not be able to build a nuclear reactor economically. It appears to require a certain amount of 20th century technological advancement, but not so much economic advancement that labor costs are too high.

France had a much better track record with nuclear in their first round of building. France can also build large construction projects without the massive cost overruns that the US has had. But they can't seem to get a next gen reactor built.