Agree with KennyMcCormckTheKing
molton plutonium with a layer of vibrainum, covered in what I mentioned on this criticism*
reactor* Also, this is not a reactor, it's just unrealistic atomic bomb. Basically an unrealistic implosion device the size of the size, also, it doesn't even have explosive lensing, thus I declare this to nor an atomic bomb or reactor, a plutonium ball covered in radiological insulation materials.