A self-sustaining nuclear reaction is a prerequisite for a fission weapon. (that's what allows the exponential doubling of fission events to occur) A nuclear r

A self-sustaining nuclear reaction is a prerequisite for a fission weapon. (that's what allows the exponential doubling of fission events to occur) A nuclear reactor was also required for the production of Pu-239, which is what 2 of the first 3 bombs were made from.