Yes, there are trace radioactive elements in almost everything natural. If nothing else, a carbon source such as coal will contain some C13 and C14.
Wow, half a pound of yellowcake uranium per tonne of coal fly ash! Interesting!
That certainly puts the TVA Kingston spill into perspective - 300 acres and a riverbed inundated with fly ash slurry. About 2.6 million cubic yards of ash, or about 6,910 tons of ash, so, ~1.5 tons of uranium spilled from a coal power plant? Talk about radioactive contamination, wow.