"Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material. MOX fuel contains plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium (LEU) fuel used in the light water reactors that predominate nuclear power generation. For example, a mixture of 7% plutonium and 93% uranium reacts similarly, although not identically, to LEU fuel.
One attraction of MOX fuel is that it is a way of utilizing surplus weapons-grade plutonium, which would otherwise be stored as nuclear waste and might be stolen to make nuclear weapons.[1] On the other hand, some fear that normalising the global commercial use of MOX fuel and the associated expansion of nuclear reprocessing will increase, rather than reduce, the risk of nuclear proliferation.[2][3]"