An international scheme to produce a controlled supply of enriched uranium has won support from the US and Russia.
Nuclear reactors need enriched uranium
The US Congress Foreign Affairs Committee has approved a bill that supports the creation of an global nuclear fuel bank.
It would be supervised by the International Atomic Energy Agency (IAEA), which inspects reactors.
The aim is to end uncertainty over states that enrich uranium and if they plan to use it for fuel or weapons.
The fuel bank would produce enriched uranium, which is a necessary ingredient in nuclear power reactors, keeping stocks of it for sale.
Countries that are building nuclear reactors would not have to make their own uranium fuel - they could simply buy it from the bank.
The US decision comes less than two weeks after Russia and Kazakhstan signed an inter-governmental agreement with the IAEA to consider setting up such a facility in Siberia.
Concerns over nuclear proliferation have most recently been raised over Iran, which is building a reactor in Bushehr and has a uranium enrichment facility in Natanz.
Co-sponsor of the bill, US Democrat Tom Lantos, stated, "Those who truly seek to develop nuclear power solely for peaceful means will jump at the chance to take part in this fuel bank."
Uranium is usually enriched using hundreds or thousands of centrifuges - cylindrical rotors moving at high-speed in an almost friction-free environment - that slowly increase the useful component of the element.
But because similar equipment is also used to enrich uranium for nuclear bombs, it is often difficult to be certain about the true intentions of states that build them.
According to the IAEA, Iran has constructed more than 1,300 centrifuges at Natanz.
Iran insists that its nuclear ambitions are peaceful, but the international community has imposed sanctions on the country over fears that it wants to develop a nuclear weapon.
A nuclear fuel bank that guaranteed uranium access to Iran could provide a possible solution to the political dilemma. It would remove the need for Iran to enrich uranium for fuel at all.
It would also allow the IAEA to more accurately measure how much nuclear fuel is being used, making it easier to spot if any uranium is diverted for non-peaceful purposes.
However, Frank Barnaby, a security expert at the Oxford Research Group, an independent security charity, does not believe it will work:
"Countries will simply not agree to it," he said.
"Iran says it has an unalienable right to enrich uranium to fuel nuclear power reactors, and there is no reason for it to choose to use the bank."
A recent paper published by the IAEA said that the nuclear fuel bank would be supervised by the IAEA but "financed on a commercial basis or by the [IAEA] Member States".
The US has committed $50m of funding to the bank, matching $50 million that was offered in 2006 by the Nuclear Threat Initiative, a US-based charity.
Following an agreement in May 2007 between Kazakhstan and Russia, a site for the nuclear fuel bank is now being considered in the remote city of Irkutsk, in Eastern Siberia. There is already a large uranium enrichment plant in the area.
Kazakhstan has about 20 per cent of the world's uranium ore and it reportedly has plans to triple production to 15,000 tonnes by the end of the decade.
The proposed nuclear fuel bank in Irkutsk will be discussed at a meeting of the IAEA's Board of Governors in June 2007.
Despite these commitments by the US and Russia, security expert Frank Barnaby says that other countries are likely to oppose the plans.
He said: "The UK and Japan have historically made objections to the idea of a nuclear fuel bank because they see enriching uranium as a secret operation and any international efforts to create a bank will mean information will leak, which threatens their security."