No it is not zero CO2 output in 2050 but about 65% reduction only, or 80% if a 25% reduction of electricity consumption is achieved. This is 1) too late, 2) not even on par with France's electricity C02 production.

And a nuclear accident would not involve closing the whole country, it would involve an exclusion zone of 10-20 km (Fukushima exclusion zone is 20km, but it include zones where the residue radioactivity is <50 mSievert, way less than some natural radioactive places), a whole lot of economic damage (but negligible compared to climate change), and between 0 and (at worst) a few thousand deaths.