If they were instead building some known/built before reactor at the same time the risk would not be so great. As with solar or wind you don't just build one single wind mill or panel but instead multiple (and hopefully at multiple different sites/projects) to minimize the risk of one of the projects going bad. (this is pretty basic risk management stuff)

Basically it all boils down to the "France is not really building much nuclear anymore" category. If you are only going to get one reactor to build every decade or two you want to make sure it is the biggest most advanced one you can get a permit for to maximize production but at the same time you maximize the risks.