Nuclear Material Disposition
In 1994 the United States declared 174 metric tons of highly enriched uranium as surplus to national security needs. A 2005 declaration added another 200 metric tons, making approximately 182 metric tons of HEU available to be down blended to low-enriched uranium for reactor use.
Y‑12 tops the short list of the world's most secure, reliable uranium feedstock suppliers for dozens of research and test reactors on six continents. These reactors can be used to test materials, irradiate new reactor fuel designs and produce medical isotopes for diagnostic and therapeutic purposes, as examples.