Source: cirosantilli/gun-type-fission-weapons-don-t-work-with-plutonium

= Gun-type fission weapons don't work with plutonium

<Gun-type fission weapons> don't work with <Plutonium-239> because of the presence of <Plutonium-240> as an impurity which leads to <fizzle (nuclear explosion)>.

Good mentions at: https://youtu.be/dgBDvnqMkT4?t=252