Nuclear power plants aren't inherently any more unsafe than the nuclear material itself before having been mined.

What makes them potentially unsafe is nuclear technology having an incredible energy density, which can be misused and the radioactive material being active even without prior activation. The latter makes many radioactive isotopes a very effective poison.

And misuse or bad practices are a general problem. One can build awful buildings, toys or government structures, too.

And if you have a look at what the worst reasonable non-political consequences from a nuclear powerplant meltdown can be, they're surprisingly harmless.

We have to Soviets to thank for their absolutely incompetent response to the Chernobyl meltdown, that we have a good idea of the long term effects. The powerplant never stopped operating, people kept working there every day for decades. Hundreds of people were never evacuated and hundreds more returned within weeks.

Just to put this into perspective: Chernobyl was effectively a dirty super-bomb dispersing 50t of highly active radioactive materials and yet the death count among anyone who didn't approach into rock throwing distance remains 0.