Today, however, thorium is getting a serious second look from some powerful global players.

With interest in nuclear power soaring, thorium is being re-examined as a potential solution to—or at least a palliative for—some of the industry's daunting problems, particularly the production of hazardous radioactive waste. Advocates say that adding thorium to a nuclear reaction would help reduce the volume of nuclear waste that is produced and help prevent civilian nuclear fuels from being converted into weapons-grade material.

With nearly three dozen nuclear reactors under construction worldwide and at least 50 more in the planning stages, world leaders are facing mounting pressure to ensure that any nuclear expansion occurs as safely and cleanly as possible.

So, could thorium, which is found in the sandy beaches of India, Australia, and the United States, be part of the answer? Some politicians certainly hope so. So do many foreign governments. In the United States last fall, Senate Majority Leader Harry Reid of Nevada and Utah Republican Sen. Orrin Hatch introduced a bill requesting $250 million for thorium research and development. Abroad, the Indian government is banking on thorium-run nuclear plants to meet its growing energy needs. Russia, France, the United Arab Emirates, and others also have expressed interest.

Of course, there's at least one big catch: At the moment, thorium isn't ready for wide commercial use. But on paper and in laboratory tests, it looks like a sleek upgrade from uranium. It's consumed much less quickly in a reaction, so it has the potential to slice in half the volume of waste that's produced. And unlike uranium, it doesn't produce plutonium that can be used in weapons. This could help allay fears, particularly in Washington, that developing countries might use civilian nuclear energy programs as a pretext for developing nuclear weapons.