Book Reviews/SuperFuel: Thorium, the Green Energy Source for the Future
What would we do if we could find a fuel that was abundant, clean, and safe? Unfortunately it seems we would shun its use for decades, largely so we could build nuclear submarines and increase our stockpile of nuclear weapons. The silvery-white metal thorium is number 90 on the periodic table of elements, two positions from its more famous cousin uranium. Of all the known energy sources on Earth, thorium is the most abundant, most readily available, cleanest, and safest element. Richard Martin tells the intriguing story of how thorium has been discounted as a nuclear fuel in favor of uranium and how it can become a green energy source for the future.
After President Dwight D. Eisenhower delivered his “Atoms for Peace” speech to the UN General Assembly on December 8, 1953, the United States launched the “Atoms for Peace” program intended to educate the American Public to the risks and opportunities of a nuclear future. The Oak Ridge National Laboratory, originally established to produce plutonium for the first nuclear bomb, turned its attention to peaceful uses of atomic energy. Oak Ridge research on a thorium-based liquid core nuclear power plant, useful for generating electric power, is described in an obscure 945-page long engineering book published in 1958.
Thorium is about four times as abundant as uranium; the United States has about 440,000 tons of thorium reserves. Used properly, thorium is much safer and far cleaner than uranium. Thorium decays so slowly it can almost be considered stable; it’s not fissile (able to sustain a nuclear chain reaction on its own), but it is fertile, meaning that it can be converted into a fissile isotope of uranium, U-233. The thorium fuel cycle results in a smaller amount of nuclear waste and less hazardous waste than do today’s uranium-fueled reactors. Liquid fluoride thorium reactors (LFTRs) can act as breeders, producing as much fuel as they consume. Because a LFTR is inherently stable and the liquid fuels can be readily drained from the reactor core, a meltdown is physically impossible.
Martin summarizes: “Thorium could provide a clean and effectively limitless source of power while allaying all public concerns—weapons proliferation, radioactive pollution, toxic waste, and fuel that is both costly and complicated to process.”
The story unfolds in these chapters:
- The Lost Book of Thorium Power—describing recent attention to the original thorium reactor work of the Oak Ridge Lab,
- The Thunder Element—describing thorium’s various characteristics,
- The Only Safe Reactor—detailing the operation, dangers, use, and costs of various reactor design options,
- Rickover and Weinberg—describing the tension between atoms for war and atoms for peace that resulted in the development of nuclear submarines and nuclear weapons. First as research director and then as overall director of the Oak Ridge labs, Alvin Weinberg advocated development of a molten salt reactor fueled by thorium. Admiral Hyman Rickover favored conventional solid-core uranium-based light water reactors, which as a by-product produced plutonium that can be refined for nuclear weapons. Martin laments: “Uranium’s victory was a triumph of military uses of science and technology over humanistic ones, of the Pentagon over the scientific community, bureaucracy over individual initiative, technological stasis over inspiration and innovation.”
- The Birth of Nuclear power—The nuclear submarine Nautilus was launched in 1954. In less than a decade Rickover built and launched ten nuclear subs, carrying the nuclear showdown to the most remote waters of the world. Yet the design for a Molten Salt Reactor fueled by thorium has remained dormant since 1959. The nuclear power industry would base their designs on the uranium-fueled reactors developed to power nuclear submarines and produce plutonium.
- The End of Nuclear Power— Funding cuts to the Oak Ridge laboratory in 1957 eventually ended their promising research and experimentation with thorium-fueled reactors. The dangers of uranium-fueled reactors went on to make international headlines. The Three Mile Island accident was a partial meltdown which occurred on March 28, 1979. On April 26, 1986 an explosion and fire at the Chernobyl Nuclear Power plant released large quantities of radioactive particles into the atmosphere which then spread over much of western USSR and Europe. The Fukushima Nuclear Power plant, damaged by an earthquake and tsunami on March 11, 2011, lost coolant, melted down, and released radioactive materials. The plant is not yet secured. No reactor ordered after 1973 was ever brought into operation the US.
- The Asian Nuclear Power Race—India is the only country in the world with a detailed, funded, government-approved plan to base its nuclear power industry on thorium-fueled reactors. India plans to build as many as 62 (needlessly complex) nuclear reactors by 2025, and most of those reactors will be running on thorium. At a Shanghai scientific conference in February 2011 China officially announced that it will begin a program to develop a thorium-fueled molten salt reactor. The People’s Republic of China plans to develop and control intellectual property with regard to thorium for its own benefit.
Thorium ore is a byproduct of mining rare earth elements. Supplies of this ore are accumulating in China which now controls 97 percent of the rare earth market. In the United States the thorium ore must be disposed of as toxic waste.
- Nuclear’ s Next Generation—The Generation IV International Forum is a collaboration of a dozen governments studying and recommending designs for advanced nuclear reactors. One of the six designs they are now considering is a thorium-fueled molten salt reactor.
- The Business Crusade—Several business ventures around the world recognize the potential of thorium-based reactors. These ventures require funding approaching billions of dollars and time frames of many years, and they are often hampered by government regulations. Viable developments will probably require government partnering with private industry to sustain the substantial long-term effort required.
- What We Must Do—Public perception of Nuclear energy options must shift, the public must perceive an accurate and objective assessment of the relative safety of nuclear energy when compared to alternatives, limited government support is necessary, and the transformation must draw on the competitive advantages of the United States. Government subsidies need to be shifted from supporting fossil fuels to supporting thorium LFTR development.
Martin is no Pollyanna, and he recognizes that thorium is no panacea. He does describe objections to the use of thorium. These include market barriers, difficulties with waste management and nuclear proliferation, and the traditionalist argument that “if it is so good it would already be in use”.
Martin is a science journalist and good story teller. The book is written at an intermediate technical level. If you stayed awake during high school chemistry class you will be able to follow the technical details. In any case you will enjoy the many stories of misfortune, short sightedness, and folly that have conspired to prevent thorium from being used as a clean, safe, reliable, and abundant fuel.
A total energy solution will prevent global warming, reduce toxic waste and pollution, reduce energy costs, preserve our wilderness areas, increase safety, and disentangle our economy and foreign policy from oil. Perhaps thorium can become an important part of that energy solution. I am writing to my congressman and senators to ask their support for thorium-based energy solutions. I encourage you to do the same.