Russia is already short of storage space for spent fuel

The plan - which still needs to be approved by the upper house of parliament - is to import waste, to store it for a number of years, and then, perhaps, to reprocess it.

A further possible stage would be to use plutonium extracted from the waste to power a special kind of nuclear reactor.

This is why supporters of the plan say the waste is not really waste, but a valuable raw material.

String of leaks

In theory, Russia's wide open spaces and large expanses of unpopulated land, ought to suit it to long-term storage of dangerous waste.

Russia has only one train for carrying spent waste

However, of the two sites earmarked to receive the new imports - Mayak and Zheleznogorsk - the former is not only in a populated area of the southern Urals, but is renowned for a string of nuclear leaks beginning in the early 1950s.

Built in 1949, it is already storing more waste than it was designed for.

Furthermore, it no longer has the ability to vitrify high-level nuclear waste - as reprocessing plants in the UK and France do - and there is no money to repair it.

An additional problem is that Mayak was designed to handle certain types of spent fuel - such as the waste from Russian nuclear submarines - but would have to be adapted to process fuel from reactors in potential client countries, such as South Korea, Taiwan or Switzerland.

Security fears

Russia's Atomic Energy Ministry admits that new storage facilities will have to be built, though it is planning to spend only $5m. Outside estimates say that even minimal upgrades to existing facilities would cost 10 times that amount.

Sceptics believe the money will go to the military, and into private pockets

Russia's ability to transport the waste is also in question.

Experts say that Russia has only one four-wagon train equipped to transport spent fuel, and have voiced concern about safety standards on the delapidated rail network.

Reprocessing the waste would produce large quantities of plutonium - which would in turn be transported across the country as it was moved to fuel-rod manufacturing plants, and on to reactors.

US officials have privately expressed concern that some of it could fall into the wrong hands, especially if Russia were to go ahead with the idea of producing mixed plutonium-uranium oxide (MOX) fuel, which produces yet more plutonium when burned in a breeder reactor.

Military ties

They have not ruled out taking steps to prevent countries supplied with US nuclear fuel from sending it for storage or reprocessing in Russia.

This would significantly cut the Russian estimates of attracting business worth $20bn.

While advocates of the plan say that it will be good for Russia's environment, because it will provide funds for clean-up activities, sceptics see the money being spent in other ways.

For one thing, they point out that Russia's civilian nuclear industry has the closest of ties with the military - Russian journalists have even quoted the former Atomic Energy Minister, Yevgeny Adamov, suggesting that military programmes could be "accelerated" with the income his ministry would receive.

Secondly, with fraud and embezzlement as widespread as they are in Russia, there is a significant risk that the money generated by waste imports would disappear into private pockets.

Mr Adamov himself was removed in a reshuffle earlier this year amid a wave of allegations of corruption.