But experts say there is unlikely to be agreement on converting all nuclear power stations to use low-enriched fuel.

BBC: Obama in push for 'world without nuclear weapons'

We are continuing research on the feasibility of converting research reactors in the United States and Russia to low-enriched uranium fuel.

WHITEHOUSE: The White House

The HEU Agreements provide for the conversion of approximately 500 metric tons of highly enriched uranium contained in Russian nuclear weapons into low-enriched uranium for use as fuel in commercial nuclear reactors.

WHITEHOUSE: Executive Order--Russian Highly Enriched Uranium

The idea was for Iran to ship 1, 200kg of its low-enriched uranium overseas to produce fuel for a research reactor, thus leaving the country for a while with too small a stockpile with which to make a bomb.

ECONOMIST: Lexington

The plan envisages Iran's low-enriched uranium being shipped overseas for processing into fuel.

BBC: Iran rebuked over nuclear 'cover-up' by UN watchdog

The other is an agreement on a proposal to take Iran's stockpile of low-enriched uranium (LEU) and send it to Russia and France for conversion into fuel rods for use in Iran's small research reactor in Tehran, which produces isotopes for cancer treatment.

BBC: Iran nuclear crisis: are new sanctions on the way?

Iran's stock of low-enriched uranium is bigger: only about half of it would be needed to produce the equivalent fuel load for the medical reactor.

ECONOMIST: Brazil, Turkey and Iran