In the U.S. film "Back to the Future", where does Doc Brown get the plutonium to power his time machine?

I loved that movie. MichaelJ. Fox at his best.

Near the start of the film when Doc is introduced, there is a background news item about Plutonium being stolen (presumably by the Libyans), at the same time Doc kicks a box with radiation trefoils under a table.

Stu, I wonder if Khadaffi saw that movie, he would have loved it

Stu, Sorry. Doc tells Marty he got it from Libyan Nationalists who wanted him to build a bomb. He never mentions a nuclear facility.