i'll have to rewatch the remastered anime, but i recall it being said somewhere that Tetsuo was emitting an energy output that was equivalent to the Big Bang. i'm even less familiar with the manga, but i recall hearing that in it, Akira himself destroyed a moon with the same amount of ease that the DBZ ilk destroy planets. pretty impressive feats, especially the former, if true. actually, i'm not sure any DBZ character has matched the energy output of the Big Bang.

still, given how in the anime Tetsuo was having fits with Kaneda and his ray gun, i'm sure Goku wouldn't have much of a problem with him.