
...to buy URANIUM from an African warlord...
The Big Bang Theory Season 8, Episode 23

because Santa wouldn't bring him
enriched URANIUM.
The Big Bang Theory Season 7, Episode 10

...and told him it's against the law
to have yellow cake URANIUM in a shed.
The Big Bang Theory Season 1, Episode 4

...and then try to buy URANIUM...
The Big Bang Theory Season 4, Episode 18

That does it. I'm getting URANIUM.
The Big Bang Theory Season 4, Episode 18