In the first such action since the 1991 breakup of the Soviet Union, 63 kg of highly enriched uranium (HEU) were removed from an Uzbek atomic research reactor over 16 days ending yesterday, the UN watchdog said in a statement.
IAEA safeguards inspectors monitored and checked the packing of the fuel into four shipments which were sent to Russia's Mayak plant, which produced plutonium for atomic bombs in the Soviet era and now processes much of Russia's nuclear waste.
The Mayak plant will convert the Uzbek spent fuel in such a way that it cannot be used in weapons, the IAEA said.
The operation took six years to plan and execute and was carried out jointly by the IAEA, Russia, Uzbekistan, Kazakhstan and the United States as part of the Global Threat Reduction Initiative.
The programme's goal is to find, secure and recover high-risk nuclear materials around the world that are vulnerable to theft for diversion into illicit atomic bomb-making.
''There was particular concern about the spent Uzbek fuel given its significant quantity and that it was no longer self-protecting,'' Pablo Adelfang, the Vienna-based IAEA's coordinator for research reactors, said in the statement.
''This means the fuel had lost its high radioactivity. In other words, it would no longer injure anyone who handled it and would not deter potential thieves.'' Moscow originally supplied the fuel to the then Soviet republic Uzbekistan for use in a research reactor, which now produces medical isotopes but still runs on bomb-grade HEU.
The IAEA is now helping convert the reactor, at Uzbekistan's Institute of Nuclear Physics 30 km (18 miles) from the capital Tashkent, to run on low-enriched uranium (LEU) which cannot be used to make warheads.
The IAEA said it had helped member states convert 33 older research reactors to operate on LEU and hoped to do the same for more than 100 others still running on HEU.
The agency has overseen other reactor-fuel repatriation operations in Libya, Romania, Serbia and Montenegro, Bulgaria, Latvia and the Czech Republic over the past three years.
REUTERS SHB KP1912