December 2013: U.S.-Russian disposal program ends
In 1994, the United States and Russia struck a deal to dispose of large stockpiles of Soviet highly enriched uranium (HEU). Over twenty years, Russia converted five hundred metric tons of HEU (enough bomb-grade uranium for 20,000 warheads) into low-enriched uranium (LEU) that the United States purchased. The United States-Russia Highly Enriched Uranium Purchase Agreement, commonly known as the Megatons to Megawatts program, ended with the last shipment of LEU reaching the United States on December 11, 2013.