The text -- which has been bogged down in delays for a year -- requires the Iranian side to return nuclear fuel Russia will provide for the atomic energy plant, Iran's first, Moscow is helping to build in Bushehr in western Iran, on the Gulf.
The draft protocol, which still must be signed by Moscow and Tehran, says once back home in Russia, the spent fuel will be placed in temporary storage and "retreated at a later date," according to a copy of the text obtained by
Both Moscow and Tehran have denied that oil-rich Iran is engaged in a covert nuclear weapons programme, and have said Bushehr will provide nuclear energy for peaceful purposes.
The assertions have failed to calm Western fears, however, and Washington has pressured Russia to obtain tighter guarantees that Iran will not use nuclear technology for military aims.
The draft protocol was approved just before the arrival here Monday of the top US diplomat for arms control, John Bolton. He will spend two days in talks with his Russian counterparts to reaffirm US concerns about Iran and North Korea, a US State Department official said Friday.
The document released Saturday said the Russian atomic energy ministry will handle further talks with Iran and arrange for the final signing of the protocol.
Atomic Energy Minister Alexander Rumyantsev said last month the nuclear fuel, now stored in a plant in Novosibirsk in Siberia, would start to be flown to Iran once the repatriation protocol was signed.
Though the document was ready a year ago, its signing has been delayed by legislative complications in Russia, some arising from a new law requiring a study of any ecological fallout.
Some analysts suggested the delays were Moscow's veiled concession to pressure from Washington to delay any nuclear program in Iran.
Washington has branded Iran a "rogue state," charging that it had "a far more robust nuclear weapons development programme" than previously believed.