About Sheldon Cooper.
Mary Cooper: I remember one summer when he was thirteen, he made a small nuclear reactor in the shed and told everybody he was going to provide free electricity for the whole town.
Well, the only problem was he had no - what you call - fissionable materials. Anyway, when he went on the Internets to get some, a man from the government came by and sat him down - real gentle - and told him it’s against the law to have yellowcake uranium in a shed.
https://youtu.be/xwdYHde4ZgM?t=80
Truth is sometimes stranger than fiction ... Google the “atomic boy scout” sometime.
And he was trying to extract Americium 241 from smoke detectors to fuel his reactor.
Of course it would take a heck of a lot of smoke detectors to get enough to do that!