[COEXERJ145]

The Nagasaki bomb held 35 pounds of Plutonium with a 32-part implosion detonator coupled with a Beryllium/Polonium injector in order to facilitate the chain reaction. That bomb also had a 12.5 kilton explosive yield.

Actually, "Fat Man" detonated with a yield of around 20 kilotons.

"LITTLE BOY" was constructed solely from U-238 and it required 100 Kg (or 220 pounds) of U-238.

"Little Boy" used Uranium 235 as its nuclear fuel. We had to use almost every bit of U-235 available to create just one bomb. Plutonium was easier to produce than U-235 was to separate so that is why Plutonium was used in both "Trinity" and "Fat Man". It would have been months before another Uranium gun weapon would have been ready where as there was enough Plutonium for three bombs and plenty more on the way.

[PSYCHO-FREEP]

I believe you have some of your facts wrong: The Facts