Fueling nuclear reactors with the element thorium instead of uranium could produce half as much radioactive waste and reduce the availability of weapons-grade plutonium by as much as 80 percent. But the nuclear power industry needs more incentives to make the switch, experts say.
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.
The anticipated surge in demand for thorium has led at least one mining company to begin buying as many thorium deposits and stockpiles as it can.
"We feel that it's inevitable that the U.S. and other countries in the world -- India of course -- will exclusively use thorium in the future," said Novastar Director of Strategic Planning Seth Shaw.
But there's just one problem: The nuclear power industry has already built its infrastructure around uranium and has little reason to invest in changing it, according to Mujid Kazimi, director of MIT's Center for Advanced Nuclear Energy Systems.
"This is a market economy so the economics will have to be in favor for thorium to move that way," said Kazimi. "It could take another 50 years for us to reach the level where uranium prices are so high that thorium looks attractive."
As an interim solution, the United States could change the way it charges power plants for the nuclear waste that they produce, said Kazimi.
Currently, waste fees are calculated as a fraction of the cost of the electricity that is produced by the fuel. Kazimi proposes charging by the volume of plutonium instead, so as to discourage its creation.
"Right now, it doesn't matter how large the fuel waste is," said Kazimi. "But if the government comes in and says we're going to increase fees in terms of waste in proportion to plutonium content, that will push for thorium."
Seth Grae, president of nuclear fuel development firm Thorium Power, said he supported the idea in principle. But he cautioned that it wouldn't be fair if the change resulted in an overall fee increase.
"Power plant operators decided to build and run their reactors based on one cost, and you can't just change the rules on them," he said.
Grae suggested that public-private partnerships could provide a better alternative by funding the development of new technologies and showing the benefits of thorium in action.
For instance, Thorium Power has been working with Russian researchers to find ways to dispose of stockpiles of weapons-grade plutonium by burning it in thorium reactors. In March, the House voted to give $5 million to the project.
If such demonstrations aren't enough to encourage thorium use, Grae noted that the change could be driven by customers from the bottom up. As deregulation allows multiple electric providers to compete in a region, customers are increasingly getting to choose where to spend their money. This means customers can essentially use their money to vote for companies that invest in responsible technologies, said Grae.
The tactic has worked before. For instance, in the 1980s the tuna industry switched to fishing methods that killed fewer dolphins after consumers stopped buying cans missing the "dolphin safe" label.
"When customers choose who their electric provider is, that's a very powerful thing," said Grae.
