Uranium-232

Uranium 232 (₉₂²³²) is an isotope of Uranium. It has a half life of 68.9 years and is a side product in the thorium cycle. It has been cited as an obstacle to nuclear proliferation using ²³³U as the fissile material, because the intense gamma radiation of ²³²U's decay products makes the ²³³U contaminated with it more difficult to handle.

Unusually for an isotope with even mass number, U-232 has a significant neutron absorption cross section for fission (thermal neutrons 75 barns, resonance integral 380) as well as for neutron capture (thermal 73, resonance integral 280).