The nuclear fuel was originally supplied to the Czech Republic by the Soviet Union for use in the Soviet-designed 10 megawatt LVR-15 multi-purpose research reactor, located in Rez near the Czech capital, Prague. In 2000, NNSA and the Czech Nuclear Research Institute completed a joint project to upgrade security of the nuclear material at Rez until it could be returned to Russia. In February 2004, Secretary Abraham and Russian Federal Atomic Energy Agency Director Alexander Rumyantsev signed a bilateral agreement between the U.S. and Russian Federation governments to facilitate the repatriation of Russian-origin HEU research reactor fuel to Russia, reported the US Government Bureau of International Information Programs.

During the one-day mission, approximately six kilograms of HEU were loaded into four specialised transportation containers. IAEA safeguards inspectors and NNSA technical experts were present in Rez to monitor the process of loading the fuel into canisters. The facility in Russia that received the material has worked closely with the NNSA to implement security upgrades.

The mission of the GTRI is to identify, secure, recover and/or facilitate the final disposition of high-risk vulnerable nuclear and radiological materials around the world that pose a threat to the United States and the international community. The initiative will comprehensively address vulnerable material and radiological materials throughout the world and secure and/or remove these materials of concern as expeditiously as possible.

This is the sixth successful shipment of HEU being returned to Russia. In the past two years, NNSA has repatriated a total of 51 kg of HEU to Russia from Romania, Bulgaria, Libya, and Uzbekistan. And in August 2002, 48 kg of Russian-origin HEU were repatriated from a research reactor near Belgrade, Serbia.