Richard Handl of Sweden was fascinated by nuclear fission. Unlike most of us, he missed the "Don't try this at home." note at the bottom with the little asterisk. He set out to try it for himself, salvaging bits of americium from smoke detectors and radium from old clock dials that glow in the dark. The he scrounged up some beryllium and set about concentrating it all together by cooking off the impurities with concentrated sulphuric acid. That's when he said he had "a little melt down" on his stove top.
(probably just a hydrogen gas explosion)
At any rate, about this time it occurred to him that there might be a law against doing some of the things he was working on and he called Sweden's Radiation Authority. In a surprisingly short amount of time a lot of policemen showed up at his home and arrested him. He was released without being charged.
A more interesting and frightening case happened in 1995 just outside of Detroit when a young Eagle Scout tried to build a breeder reactor in his families tool shed in the back yard and very nearly succeeded.
The article in Harper's is long, but fascinating as well as chilling.
The following are small excerpts:
"When his Geiger counter began picking up radiation five doors down from his mom’s house, David decided that he had “too much radioactive stuff in one place” and began to disassemble the reactor. He placed the thorium pellets in a shoebox that he hid in his mother’s house, left the radium and americium in the shed, and packed most of the rest of his equipment into the trunk of the Pontiac 6000."
"A Superfund cleanup took place between June 26 and 28 at a cost of about $60,000. After the moon-suited workers dismantled the potting shed with electric saws, they loaded the remains into thirty-nine sealed barrels placed aboard a semitrailer bound for Envirocare, a dump facility located in the middle of the Great Salt Lake Desert."
Be seeing you.
Other sources: Raw Story