Relative to watts produced, coal kills 4,000 times more people than nuclear power.

Our pervasive sense that nuclear is more dangerous, when the opposite is so clearly true, comes at least in part from a cognitive bias called the "availability heuristic" -- memorable events that are easier to think of, like nuclear disasters, tend to seem more common. 

Counterweight your availability heuristic by reading up on Alexis Madrigal's list of 
25 energy-related disasters from the last year. Most are coal mine accidents and refinery explosions, and the vast majority of the deaths should be filed in that big box on the right.
Text and Image from
Read more:
The triumph of coal marketing,"
25 Other Energy Disasters from the Last Year," The Atlantic