Well, it does, but very slowly. Depleted means it contains only a very small percentage of fissible U235. The bulk being made up of U238, which also decays - em

Well, it does, but very slowly. Depleted means it contains only a very small percentage of fissible U235. The bulk being made up of U238, which also decays - emitting alpha radiation - but with a half life of ~2.5 billion years.