So If you have noticed in Fallout 3, in Megaton, there is an atomic bomb in the middle of the town. If you want to disarm it, here is some tips. Have at least explosions level 50 Then after you have gained explosion level 50, go over to the atomic bomb, then press X on it, then select attempt to disarm the bomb. It should work (unless your explosions level was not 50). But the big surprise after you've disarmed the bomb... is up to you to find out for yourself.