...can probably just build a bomb on their own just fine.
Building a bomb with effects comparable to a reactor meltdown requires significant resources. Running a few planes into a building requires - plane tickets.
You do remember that 9/11 thing, do you?
There are minute possibilities of terrible disasters with almost any facility
You pull every last ridiculous straw, don't you?
Yes, other bad things happen, too. If you think long and hard then you might grasp the difference in magnitude.
Hint: Chernobyl is estimated to have caused 250.000 deaths. 1700 square miles of land have been rendered permanently inhabitable. The numbers for Fukushima are still outstanding.
...can probably just build a bomb on their own just fine.
Nuclear power plants don't require perfection. There are minute possibilities of terrible disasters with almost any facility. Nuclear plants do have some particularly disconcerting problems that seem fairly obvious and must be mitigated against, but I think we can allow for the fact that with or without a nuclear plant, bad shit can happen, and actually without said plant, bad shit will happen.
Bhopal didn't have a nuclear power plant, just a measly ol' pesticide plant.