FROM: U.S. STATE DEPARTMENT
Arms Control and International Security: U.S. Support for Fissile Material Reductions
05/05/2015 12:24 PM EDT
U.S. Support for Fissile Material Reductions
The total U.S. highly enriched uranium inventory as of 2004 was 686.6 MT. In declarations in 1994 and 2005, the United States declared that a significant portion of that inventory totaling 374 MT of HEU would be removed from further use as fissile material in nuclear warheads.
To date, the United States has down-blended more than 146 MT of HEU—enough material for more than 5,800 nuclear weapons.
The landmark 1993 United States-Russia HEU Purchase Agreement eliminated 500 metric tons of Russian weapons- origin HEU, which was converted to LEU and shipped to the United States where it was used for peaceful purposes as fuel in American nuclear power reactors. The amount downblended was equivalent to roughly three warheads worth of HEU per day for most of the last two decades.
In 2009, the United States reported the plutonium inventory was 95.4 metric tons. In 1994 and 2007, 61.5 metric tons of plutonium had been declared excess and removed from further use as fissile material in nuclear warheads.
The U.S.-Russian Plutonium Management and Disposition Agreement requires each state to dispose of no less than 34 metric tons of plutonium declared excess.
Since the early 1980s, the size of the U.S. nuclear complex has shrunk to approximately half of its original size and reduced the workforce by two-thirds.
Looking forward, the United States anticipates shifting from retaining large numbers of non-deployed nuclear warheads towards a more responsive infrastructure. Investing in a more modern physical infrastructure can allow for further reductions in total nuclear forces.