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).