There have been studies (this one, for example) that suggest the total radioactivity-related health impacts from coal power exceed that of nuclear power by an order of magnitude. That's not all pollution-related deaths for coal -- just those associated with radon exposure inside of mines, and radioactive materials embedded in coal going out into the environment. For all the fear-mongering about nuclear, it's hard to find a less dangerous source of base load generation using present-day technologies. Maybe once grid-scale batteries are available at scale, they could replace nuke plants, but that's a solution ten years too late for an environmental problem we have to fix right now.