Mark Massie and Leslie Dewan giving a TEDx New England presentation on molten salt nuclear reactors.
A new model of nuclear energy is set to radically transform the nuclear power industry in the near future.
According to MIT graduate students Leslie Dewan and Mark Massie, a revised design of nuclear power stations using a molten salt core can produce vast amounts of electricity utilizing the discarded nuclear waste of conventional reactors – thereby inaugurating a new age of nuclear power as a “green” energy source that protects against climate change.
Surprisingly, many scientists, researchers and industry leaders are backing their innovative concepts – as does billionaire tech venture capitalist and PayPal co-founder Peter Thiel. Through FF Science, a newly formed branch of his Founders Fund that focuses on high tech science and engineering ventures, Thiel has invested $2 million in Transatomic, Dewan and Massie’s nuclear energy startup.
Dewan and Massie were both named to the Forbes list of “30 Under 30” in Energy in December 2012, and it’s easy to see why. With their youthful exuberance and lucid presentations that make nuclear science accessible to lay audiences, they make a strong case for an entirely new vision of what nuclear energy can mean in the 21st Century
“I think I can save the world with nuclear power,” says Transatomic CEO Leslie Dewan, with a light smile and a soft laugh that is confident and serious, although slightly tongue and cheek.
Dewan and Massie’s optimism was sparked by their own investigation and reviews of previous nuclear power plant designs made during the 1950s, in the early stages of America’s nuclear energy industry. The use of molten salt to cool the high temperatures and intense power of nuclear fission reactions was one of the engineering models developed by the Oak Ridge National Lab in Tennessee. However, the molten salt design was considered bulky and had low power density. Instead, much of what evolved in the early industry stages was pioneered by the U.S. Navy, which was in a race with the Soviet Union to build the first nuclear powered submarine. The submarines were built using light water as the cooling system, which then became the structural standard that has been used by the nuclear power industry ever since.
The original Oak Ridge molten salt reactor core, first operated in 1965.
“They chose to go with this design not because it was the best technology, but because it was the technology they understood the most,” says Massie.
Dewan points out that the focus on light water reactors also clouded the potential safety features of the molten salt design, because the industry was young and the world hadn’t experienced nuclear disasters like Fukushima, Chernobyl and Three-Mile Island. But in the wake of these nuclear mishaps concerns about safety have become a priority, with some countries like Germany, making policy decisions to scale back or eliminate their reliance on nuclear energy.
Dewan and Massie did an extensive review of documents pertaining to early experiments in nuclear energy, and they were able to develop their own revisions and innovations on the original molten salt reactor design. Their new design uses Zirconium Hydride instead of graphite as a moderator, which is much more effective at slowing down neutrons in the nuclear fission reactions. Graphite made the reactor core very bulky with low power density. The new Transatomic reactor uses a different kind of salt – Lithium Fluoride and Uranium Fluoride – that can run on spent fuel rods and increases the power density.
Dewan and Massie claim that their Waste Annihilating Molten Salt Reactor (WAMSR) consumes the waste of conventional plants and converts 98 percent of the remaining energy. While a conventional plant produces about 20 metric tons of waste per year, the WAMSR produces only 3 kilograms of waste per year, which is approximately the size of a baseball. The technical details of the new design are outlined in detail and available to the public through Transatomic’s technical white paper.
Light water reactor plant design vs. new Transatomic molten salt reactor plant design.
The WAMSR design also includes an auxiliary containment system, which releases electrically cooled salt into the reactor core if it may overheat. Dewan and Massie describe the plant as “walk away” safe. Even if the operators were not on the site, the plant will “coast to a safe stop” over a few days.
Using current construction techniques, the new plants can be built at two-thirds the cost of conventional plants. The plant designs can also be constructed on or near current nuclear facilities, making it easy to access and use the existing spent fuel rods.
In addition to private investment from Peter Thiel and the FF Science venture capital fund, Transatomic is also receives grants from the U.S. Department of Energy. However, some observers have noted that large scale implementation of the new systems will require – much like in the 1950s – substantial investment from the U.S. government, which appears unlikely in the current atmosphere of conflict in Washington.
Nonetheless, Dewan and Massie are bullish on the global prospects for their new designs, given that China alone has 14 nuclear power plants, with 78 more under construction or being planned and another 120 proposed. The China factor becomes even more important when considering that CO₂ emissions in the Western world are gradually lowering in growth, while China’s emissions are skyrocketing.
There are a growing number of advocates of the molten salt design in the U.S., including the Energy from Thorium Foundation and a consortium with U.S. Department of Energy, that includes Massachusetts Institute of Technology, the University of California, and the University of Wisconsin. Nuclear engineer Don Amerine, a consultant to the Energy from Thorium Foundation is eager to see the U.S. put more money and resources into developing molten salt reactors.
“Unlike light water reactors where we only consume about 5% of available fuel and then we remove the rods for structural integrity considerations, with fuel in a hot and highly radioactive state, in the LFTR (liquid fluoride thorium reactor), almost 100% of the fuel is consumed,” says Amerine.
“It solves four of the most pressing problems facing the nuclear industry: ecological stewardship, public safety, non-proliferation, and cost-efficiency. Only an advanced reactor that meets all four goals at once can truly change the game and allow for broad adoption of nuclear power,” says Dewan.
This article is part of a blog series I am writing called, “Signs of the Times: Hidden Seeds of a Benevolent Future.” The series is sponsored by Solution Link, a digital marketing firm and highlights critical developments, technologies and innovations that are creating constructive and far-reaching societal change. You can find the Hidden Seeds series, as well as Solution Link’s free digital marketing e-book on the Solution Link web site and blog.