The U.N. nuclear agency says tons of highly radioactive nuclear waste from a defunct Serbian reactor have been repatriated to Russia.
An official familiar with the operation said Wednesday the waste included 13 kilograms (28.66 pounds) of uranium enriched at a level close to that used to make nuclear warheads.
The International Atomic Energy Agency, who coordinated the project, said 2.5 metric tons (2.76 tons) of the spent fuel arrived Wednesday at a secure Russian facility from Serbia's Vinca reactor.
An IAEA statement said the amount is the largest single shipment of its kind so far repatriated under an international program to return such material.
The agency said it took more than a month for the shipment to reach the Russian reprocessing facility.