As part of its efforts to safeguard potentially weapons-useable atomic material, the United Nations nuclear watchdog has assisted Bulgaria with the removal of highly-enriched uranium stored at a shut-down research reactor in Sofia.
The substance, which was 36 per cent enriched and took the form of fresh fuel, was airlifted earlier this month to Russia, the original supplier, according to the International Atomic Energy Agency (IAEA). Agency safeguards inspectors monitored and verified the packaging of the fuel, which Moscow says it will re-fabricate into low-enriched uranium.
The United States Department of Energy funded the removal under a cooperative US-Russia-IAEA programme called the Tripartite Initiative which aims to further nuclear non-proliferation. The Tripartite Initiative facilitates the return of both fresh and spent fuel from Russian designed research reactors abroad. The Sofia uranium was originally supplied by Moscow in the 1960s.
There are currently about 80 research reactors around the world that still have potentially weapons-grade high-enriched uranium subject to international control. The Vienna-based IAEA has played an active record in helping countries to convert their research reactors from high- to low-enriched uranium, within the framework of programmes to improve the overall safety and security of research reactors, particularly ageing reactors, and their spent fuel storage facilities.