They had been interested in thorium -- a radioactive element that can fuel nuclear reactors but not be processed into weapons.
VOA: special.2010.10.15
It does not -- the key element of any plausible proposal to get our deficits and debt under control is that it have balance so that it is not unfairly burdensome to any sector of American society.
MPs will vote for some kind of democratically-elected element, the notion of an entirely-appointed second chamber (not very different from the existing one) will win more support than any of the hybrid options.