True, but it doesn't have the incredibly horrific non-carbon pollution problems of coal. The things almost every coal plant in the world does to nearby rivers would nauseate most people. Fly ash produced by coal plants releases one hundred times the radiation into the environment as a nuclear plant of the same capacity.
"A lot" is relative. From what I can tell, coal ash contains about the same amount of uranium and thorium as granite and slightly more than ordinary soil. (Of course, it's less concentrated in the coal itself, which is largely carbon and hydrocarbons that gets burnt off.) The main reason coal power releases so much radiation compared to nuclear because there's a lot of coal burnt and normal operation of nuclear power plants also releases very little.
What's more scary is the production of things like rare earth minerals - that quite heavily concentrates the uranium and thorium as part of the extraction process, producing large quantities of relatively radioactive mining waste.
