https://read.amazon.com/?asin=B00KTTY4A4&ref_=kwl_kr_iv_rec_5
Even a Microscopic Piece of 95% U-235 can produce Big Heat if it is Detonated by a Burst of Neutrons. Such a Burst Can Be Arranged By Polonium and Beryllium Metals Being Forced Together Hard and Fast.
For explosion you want a chain reaction that consumes your entire piece of U-235.
https://robertfentongary.com/?p=12935
A rocket nozzle with 4 types of ultra-thin graphene tape fed into a vise-tamper would be a nuclear rocket.
Amor Fati (Love Your Fate)
Inventions by Robert Fenton Gary 