Nuclear material that can be used for the manufacture of nuclear
explosive devices without transmutation or further enrichment. It
includes plutonium containing less than 80% 238Pu, high
enriched uranium and 233U. Chemical compounds, mixtures
of direct use materials (e.g., mixed oxide (MOX)), and plutonium in
spent reactor fuel fall into this category. Unirradiated direct use
material is direct use material which does not contain substantial
amounts of fission products; it would require less time and effort
to be converted to components of nuclear explosive devices than
irradiated direct use material (e.g., plutonium in spent reactor
fuel) that contains substantial amounts of fission products.