Taking the uranium out

Hotwired reports on new directions in research on using fuel sources other than uranium for nuclear power:

Scientists have long considered using thorium as a reactor fuel -- and for good reason: The naturally occurring element is more abundant, more efficient and safer to use than uranium. Plus, thorium reactors leave behind very little plutonium, meaning that governments have access to less material for making nuclear weapons.

But design challenges and a Cold War-era interest in using nuclear waste byproducts in atomic bombs pushed the industry to use uranium as its primary fuel.

Now, as governments look to prevent the proliferation of nuclear arms and as environmentalists want to reduce the volume of nuclear waste building up around the world, thorium is again drawing attention.

Over the past several years, studies in the United States and Russia have yielded solutions to some of the issues that troubled earlier researchers. And in January, India -- which has the world's second largest reserve of thorium behind Australia --announced it would begin testing the safety of a design of its own.