"mining scale"

Don't need much area, depends on the concentration of radioactives. I have a small mine that's just a pegmatite body about the size of a house which produces almost marble-sized chunks of a thorium-uranium mixed metamict mineral (I suspect samarskite but Raman and XRD can't give any ID,) you'd barely notice it from a private airplane's typical flying height, however you could dig the entirety of it up and you'd have enough unprocessed uranium for some real fun.