US President George W. Bush last year announced a 1.2-billion-dollar plan to develop hydrogen-powered cars to decrease US dependency on foreign oil.

Researchers from the US government's Idaho National Engineering and Environmental Laboratory (INELL) and the private company Ceramatec Inc. said a computer model showed they could separate hydrogen from hot water by using a nuclear reactor.

The method would yield more hydrogen than does electrolysis, which runs electricity through water to separate hydrogen and oxygen.

The conversion rate of water into hydrogen ranges between 45 and 50 percent in high temperatures, compared with about 30 percent in electrolysis, the researchers said.

"This is a breakthrough ... (and) a crucial first step toward large-scale production of hydrogen from water, rather than from fossil fuels," said Stephen Herring, consulting engineer at INELL.

The nuclear reactor method should be cheaper and more environmentally friendly, Herring added.

However, the method works with Generation IV nuclear reactors, which the United States no longer makes.

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