Highly enriched uranium (HEU) can be used to make a nuclear weapon. In 1996, the Department of Energy (DOE) announced plans to reduce the proliferation threat from stockpiles of surplus HEU by downblending, or converting, it to low-enriched uranium (LEU). In this form, the material can be used as commercial nuclear reactor fuel but is unsuitable for use in nuclear weapons.
Surplus HEU is currently stored at several DOE facilities, but primarily at NNSA's Y-12 National Security Complex in Oak Ridge, Tenn. When ready for downblending, it is shipped to a private sector facility in Erwin, Tenn, or downblended at DOE/NNSA facilities located at the Savannah River Site in Aiken, S.C., and the Y-12 National Security Complex in Oak Ridge, Tenn. All shipments of surplus HEU are moved using NNSA's secure transportation system designed to ensure the safety and security of sensitive government material.
A total of 209 metric tons (MT) of U.S. HEU has been declared surplus to U.S. defense needs and designated for downblending. To date, more than half of this HEU has been downblended.
HEU Downblending Project Highlights
Of the 209 MT of HEU, NNSA has committed to downblending projects totaling 175 MT with the remaining 34 MT expected to become available between now and 2050. To date, NNSA has successfully downblended 119 MT of the HEU.
Downblending projects to date include:
- Transferred approximately 47 MT of surplus HEU to the United States Enrichment Corporation (USEC), which was downblended into LEU commercial nuclear reactor fuel (project completed June 2006);
- Transferring 46 MT of surplus HEU for downblending and use as fuel in Tennessee Valley Authority reactors;
- Downblending up to 23 MT of surplus HEU for use as low-enriched uranium (LEU) research reactor fuel;
- Downblending 17.4 MT of HEU for the American Nuclear Fuel Reserve;
- Downblending 12.1 MT of HEU for the MOX LEU Backup Inventory Project.
