There is 3 catastrophes related to nuclear. The only one where radiation actually killed people was Chernobyl. Displacement of hundred thousands, considered contaminated thus excluded by their peers, probably caused more life-years lost than the radiation itself.

The UNSCEAR (GIEC group1 equivalent for radiation) rapport on Fukushima is enlightening.

Nuclear have a lot of drawback too (mining pollution, waste disposal) but is probably the energy ressource that killed the less people/MWh produced, and for sure the one destroying the less ecosystem/MWh.

I used to be anti-nuclear for the wrong reasons until an observation internship in a hospital were i learned how dangerous radiation actually was, but realistically, until a new breakthrough on superconductor is found and allow us a less expensive, more lasting magnetic containment for plasma, i don't see any other energy that can replace coal/gaz.