The Future of Thorium

Stephen DeAngelis

August 12, 2009

During his presidential campaign, Senator John McCain “laid out his vision for 100 new nuclear plants—45 of them to be built by 2030 [“Nuclear’s Tangled Economics,” by John Carey, BusinessWeek, 7 July 2008 print issue]. During a campaign speech McCain stated, “The French are able to generate 80% of their electricity with nuclear power. There’s no reason why America shouldn’t.” McCain also wanted “to borrow from the French playbook by reprocessing and reusing spent nuclear fuel and by providing government incentives to get all this done.” Carey went on to report that although “France’s existing 59 atomic plants are relatively trouble-free, its largest nuclear company, Areva, has run into difficulties building next-generation reactors in France and Finland.” In addition, “France … still hasn’t found a permanent home for a growing pile of highly radioactive waste.”

 

Discussions about nuclear energy immediately raise strong reactions in both proponents and opponents. Proponents, like Senator McCain, tout the fact that nuclear-powered electricity generating plants produce fewer greenhouse gas emissions than those generated by power plants that use fossil fuels. On the other hand, opponents note that nuclear power plants create serious nuclear waste challenges, like those found in France. Generally thrown into the discussion in the U.S. is that America wants to become “energy independent,” by which most people mean they don’t want to import oil from foreign countries. Electricity generation, however, is more about coal than oil. The primary reason that coal is used is because it is abundant and relatively cheap. Because it remains abundant, U.S. politicians have been pressing for “clean coal technologies” [for more on that subject see my posts The Search for Clean Coal, The Conundrum of “Clean Coal”, and Carbon Capture and Storage]. If abundance remains an important criterion for the future, then more and more people may start looking at thorium. Thorium is a radioactive silvery-white metallic element that is recovered commercially from monazite. It is used in a number of commercial applications, but its most important trait may be its abundance. By most estimates, the energy available from the world’s supply of thorium exceeds the energy available from all of the world’s uranium, coal, and oil combined.

 

Seth Grae, president of Northern Virginia-based Thorium Power Ltd., has become thorium’s greatest advocate [“If Nuclear Power Has a More Promising Future … Seth Grae Wants to Be the One Leading the Charge,” by Leslie Allen, Washington Post, 2 August 2009]. Grae believes that the use of thorium can make nuclear energy safer, less expensive and more effective. Here’s his pitch:

“Cars and nuclear power plants both run on fuel, he begins, and aims his analogy straight ahead. Cars that once took leaded gasoline now run on a newer, less toxic and environmentally more benign gas: unleaded. The same concept holds true for the 104 nuclear power plants that supply 20 percent of this country’s electricity, Grae says, as well as for the dozens of new reactors expected to come online worldwide in the next few decades. ‘Everyone knows nuclear plants run on uranium, right?’ Grae continues, and then launches into a litany of uranium’s persistent problems. Nuclear plants in service today run on a fuel mix that generates enough spent uranium and plutonium to build dozens of nuclear weapons each year in the United States alone. That waste will remain highly radioactive for hundreds of thousands of years. It already adds up to more than 78,000 metric tons, with highly uncertain prospects for safe, long-term storage. But what if these very same nuclear power plants were able to run on a different fuel mix? A mix that: first, would generate only a minor amount of waste, if any, that could be used to build a nuclear weapon. Second, could destroy tons of plutonium instead of generating it. Third, would produce less than half the volume of current fuel waste, which would remain radioactive for only a few hundred years. And, fourth, is made from an element far more abundant, less radioactive and cheaper than uranium: thorium. And what if the technology had already gotten positive reviews from the American Nuclear Society, the World Nuclear Association and, in particular, from the International Atomic Energy Agency (IAEA), the world’s nuclear watchdog, which, in a 2005 report titled Thorium Fuel Cycle — Potential Benefits and Challenges, called it ‘an attractive way to produce long-term nuclear energy with low radiotoxicity waste?’ You’d have the nuclear equivalent of unleaded gas, in Grae’s analogy.”

Two countries who would love to see thorium become a primary fuel source for generating electricity are India and Brazil. They are the chief commercial sources of the monazite sand from which thorium is obtained. Although Grae has his skeptics, he has ready answers for most of the questions they raise. The use of thorium as a nuclear fuel is not new. According to Allen, Alvin Radkowsky, one of the Navy’s top nuclear scientists for over 20 years and the inventor of its seagoing reactors, “designed a reactor that was built and successfully operated by a company named Shippingport that ran uneventfully for a few years on thorium-based fuel.” Those were the days of the Cold War, however, and, as Allen reports, “Cold War powers believed they could muddy the waters of intent by enriching uranium for military purposes and for civilian nuclear energy in the same buildings.” It also meant that thorium-powered reactors never caught on. Because uranium fuel-based reactors became the norm, nuclear power and nuclear weapons became inextricably connected in the public’s mind; which is one reason that Iran’s pursuit of nuclear energy raises so many concerns. “In 1979,” Allen continues, “the near-core meltdown at the Three Mile Island nuclear station near Harrisburg, Pa., dealt the industry’s prospects a body blow by turning public opinion against it.” The Chernobyl crisis almost a decade later cemented the dangers of nuclear power in the public’s mind.

 

Allen reports that Radowsky had never lost his passionate interest in thorium.

“Radkowsky … envisioned a new nuclear fuel that would allow even unfriendly governments — Cuba’s and North Korea’s topped the list in those days — energy-generating capacity without creating weapons-usable materials. ‘If we don’t put a stop to conventional uranium cores now, nuclear terror will ensue, and the use of legitimate nuclear energy will be barred worldwide,’ Radkowsky said in a 1997 interview.”

Grae first met Radowsky in 1991 after being contacted by the scientist. Radkowsky wanted to pursue his ideas, but didn’t know exactly how to do it. Allen continues the story:

“Radkowsky was no businessman; he had no idea how to go about locating the expertise he needed. But he did have a wide network of friends and acquaintances. One was an Israeli investor who knew a New York real estate developer who knew Grae and had done business with his father, Joel, a high-tech entrepreneur and developer. Word got back to Radkowsky about Seth Grae, whose cases dealing with international law, high-technology companies and Russian refusenik physicists seemed to intersect in a relevant way. ‘One day, I was sitting there in my office and in came a fax from Alvin, describing this new technology,’ Grae recalls.”

It wasn’t exactly a match made in heaven. Grae thought that Radkowsky’s ideas sounded like “a mix of has-been and pie-in-the-sky” concepts. As a result, he turned down the idea of working with him. Over the next year, however, Radkowsky persisted in efforts and eventually Grae came on board. In 1992, Radkowsky Thorium Power Corporation was born and the event went largely unnoticed. All the while, Radkowsky continued to modify his designs.

“In 1995, Radkowsky tweaked his fuel design into something close to what Thorium Power has today. His new ‘non-proliferative’ fuel involved a concept known, with almost storybook simplicity, as a “seed and blanket” design. Thorium can’t sustain a chain reaction on its own. It needs something else — a very small amount of a fissile material, such as uranium, whose nuclei can be split more readily — to kick-start the reaction by bombarding the thorium with spare neutrons. So Radkowsky wrapped clusters of ‘seeds’ — fuel rods made of uranium and zirconium — in much larger ‘blankets’ of rods made of thorium oxide pellets. The unique reaction that followed, he believed, would result in real improvements over the standard all-uranium nuclear fuel. His goal was that no weapons-usable plutonium be generated in the reaction, and that any weapons-usable uranium isotopes produced be consumed in the process. Radkowsky’s fuel would leave comparatively little waste and less radioactive waste. Among other intriguing characteristics, it also would have a fuel cycle that would allow most of its fuel to last several years longer than uranium fuel in a reactor core before needing to be replaced and stored. Though other countries, such as Canada and India, were experimenting with thorium, Radkowsky’s formula was the only one that could potentially be dropped into existing light-water reactors, such as the U.S. fleet of nuclear power plants.”

With Russia and the United States re-entering discussions about how to decrease their stockpiles of nuclear weapons, one would think that Radkowsky’s seed/blanket reactor was a match made in heaven. That is because the “seed” rods are “made of plutonium from old nuclear weapons (or from nuclear waste from civilian reactors) instead of uranium; thus, thorium could theoretically create electricity while disposing of old nuclear weapons. Sounds like a win-win. Unfortunately, Radkowsky died in 2002 without ever seeing his ideas gain traction. One of the problems is that there are other contending methods for destroying plutonium. The primary contender is a mixed uranium-plutonium oxide fuel (MOX) process “based on technology developed by the French government-owned nuclear firm Areva. But MOX produces two-thirds as much new plutonium as it burns, resulting in a net increase.” In other words, it doesn’t sound like MOX should be a contender at all. In addition, critics worry “about proliferation risks, since spent MOX fuel can be separated and its plutonium used for weapons.”

 

In the spring of 2005, a report commissioned by the Department of Energy and conducted by Westinghouse, concluded that thorium-based fuel “could destroy much more plutonium than MOX and do it three times faster than MOX at a third of the cost, leaving much less toxic waste behind. Unlike MOX, it wouldn’t require that new plants be built to manufacture the fuel, either.” So why hasn’t thorium-based process caught on? The simple answer is politics. The Department of Energy’s National Nuclear Security Administration (NNSA), which handles the disposition of excess uranium and plutonium, “concluded that the thorium technology was ‘unproven’ and ‘not suitable’ for disposing of the surplus military plutonium.” The report might have been biased by the fact the DOE had already committed to spend billions to build a Mixed Oxide Fuel Facility at its South Carolina Savannah River Site. As of this posting, however, the facility has no customers for the fuel it will be generating [“Duke Energy interested in MOX fuel, despite dropping contract,” by Scott Miller, Charleston Regional Business Journal, 17 March 2009].

 

The thorium-based process has converted proponents on both sides of the Congressional aisle, the chief of which are Republican Senator Orrin Hatch and Democratic Senator Harry Reid. Despite the billions already spent on the DOE’s MOX facility, the House of Representatives passed “the landmark American Clean Energy and Security Act” in June and “the Senate version is expected to be brought up on the floor this fall.” Political wrangling aside, Allen asks an important question. Will the public ever again embrace nuclear power as source for electricity?

“Global warming has altered some people’s perceptions about nuclear power: What was long regarded by many as a dirty and unacceptably dangerous business, from the mining of uranium through the disposal of highly radioactive waste, is now more widely seen as a greener alternative to fossil fuels that produce planet-warming greenhouse gases. Others, however, say nuclear power is no panacea. To avoid global warming’s catastrophic consequences, ‘we have just 20 years or so to turn it around,’ says Christopher Paine, a nuclear expert at the Natural Resources Defense Council in Washington. ‘In that time, nuclear can make only a very modest contribution.’ Lead times for licensing and construction of new nuclear plants can run to decades. There is a bottleneck in the creation of reactor vessels and components, and as the U.S. nuclear workforce ages, expertise is rapidly being lost. Americans also may balk at funding new plants, which would carry price tags in the billions and be supported partly by generous federal incentives. And looming over it all is the question of safety.”

While Seth Grae hopes that America embraces nuclear power technology, he is sure that other countries will. He “believes that possibly half of all the new commercial nuclear reactors built in the next 20 years will be in countries that have none yet, places such as Vietnam, Argentina, Turkey, Belarus, Sri Lanka and the United Arab Emirates.” For security analysts concerned about nuclear weapon proliferation, thorium-fueled reactors are the only way to go. As a side story, Allen notes that countries like the UAE that have significant oil reserves are interested in nuclear power technology because they know the oil will some day run out.

“Oil, for as long as it lasts, is more profitable as an export. What to do? The supply of gas is limited; imported coal, another option, is dirty; wind, undependable. You can invest billions in solar generation, as Abu Dhabi has. And you can develop policies to explore nuclear power. When Abu Dhabi’s government heard about thorium, it called in Thorium Power. The company helped the government develop a policy as it began to explore a nuclear future. Among other safeguards, the policy commits the UAE to buying nuclear fuel abroad and returning it when it’s spent. In doing that, it becomes the first country to renounce its right under the Nuclear Non-Proliferation Treaty to enrich uranium or reprocess plutonium, which cuts off its means of making its own weapons. It has agreed to intrusive and unannounced inspections by the IAEA. The policy ‘is very far-reaching, a model that other states going into nuclear energy could use,’ says nuclear expert Matthew Bunn of Harvard University. It now also forms the basis of a new nuclear-cooperation pact with the United States, awaiting congressional action — controversial because of the UAE’s ties to Iran — that would help the UAE become the first Arab country to develop nuclear power. One thing the UAE’s policy did not commit to was thorium itself. Instead, David Scott, director of economic affairs for the emirate of Abu Dhabi’s Executive Affairs Authority, calls Thorium Power’s fuel a ‘long-term solution.’ In the meantime, though, the UAE has hired Thorium Power to help it develop a framework for its civilian nuclear industry.”

It will be ironic if other countries develop thorium-fueled reactors that become more efficient and effective at helping to destroy excess plutonium than the countries that built the stockpiles in the first place. To reduce those stockpiles at the same time generating much needed electrical power appears to be a winning formula — even if the process is not entirely free of creating nuclear waste.