By: Kelly de la Torre Issue: Transformation Section: Business The United States electric utility industry is facing an energy dilemma defined by an aging generation fleet and distribution system, a need to expand transmission, increasingly stringent environmental regulations, and disruptive changes in the economics of fossil fuel resources—to name just a few challenges. In part, these forces are driving a sweeping transition from coal to natural gas. Indeed, we are in the midst of a natural gas boom, and the low cost of natural gas is creating jobs and helping to fuel economic recovery. However, the natural gas boom isn’t going to last forever, and if we want to really do something about our energy dilemma and global warming, says Richard Martin, author of the new book about thorium, SuperFuel: Thorium, the Green Energy Source for the Future, natural gas alone is not going to cut it. “Leading the way in the next big energy technology is the way to long-term prosperity,” urges Martin.
A thorium revival could help transform the energy dilemma into economic opportunity. Martin firmly believes that we can’t build our way out of the current energy dilemma using natural gas or renewable energy alone. “We need a transition period, and the only way we’re going to do that is nuclear power.” When asked about the impetus for his book, Martin responded that “thorium is an amazing energy source and it has a tremendous backstory. We aren’t discussing a whiteboard technology. We’ve proven the technology, and now we’re watching China and India take the lead and beat us with it.” Luckily, thanks in part to Kirk Sorensen and Kirk Dorius, co-founders of Flibe Energy, we are undergoing a thorium revival. The stakes are high, and the potential benefit to the United States is almost inconceivable.
Flibe Energy is leading the way with a technology and fuel source that could transform the nuclear energy industry. According to the co-founders, the company will develop small modular reactors based on liquid-fluoride thorium reactor (LFTR) technology. “Liquid-fluoride reactors operate at high temperature but not at high pressure because they use a chemically stable medium as the fuel and the coolant, making them much safer to operate than conventional reactors. Thorium is the only abundant nuclear fuel that can be efficiently utilized in a thermal-spectrum reactor and is uniquely chemically suited for use in a fluoride reactor,” Sorensen explains.
This promising technology was proven to work in the 1960s but was then nearly forgotten. Thorium’s potential was defined by key personnel from the Manhattan Project, including Nobel Prize-winning physicist Eugene Wigner and his protégé, Alvin Weinberg. According to Sorensen, in 1955, Weinberg took charge of the Oak Ridge National Laboratory (ORNL) in Tennessee and began a personal campaign to realize the benefits of thorium. Under his leadership, two prototype molten salt reactors were built that demonstrated key technologies needed to bring thorium energy generation to reality. At the time, however, politics and industry momentum were already firmly committed to solid-uranium-fueled, water-cooled reactors and the idea of plutonium fast breeder reactors. Weinberg grew increasingly at odds with the U.S. Atomic Energy Commission over his repeated concerns about these solid-fueled reactors, and despite his 20,000 hours of successful molten salt reactor operation, the U.S. Atomic Energy Commission ultimately removed Alvin Weinberg as head of ORNL and canceled his project.
With Weinberg’s departure the research into the potential of thorium as a nuclear fuel was nearly forgotten. Says Sorensen: “Textbooks did not mention it. Nuclear engineers were never taught about it in school. Even personnel at Oak Ridge, unless they happened to personally know one of the ‘old-timers,‘ did not know what had taken place in the ridged forests of eastern Tennessee in the 1960s.” Now, several decades later, Flibe Energy is in the process of demonstrating how thorium provides an energy solution.
In contrast to renewable energy resources such as wind and solar, whose energy must be opportunistically captured and consumed, stored energy resources, such as hydrocarbons, allow energy to be controlled and released at a desired rate. Another stored energy resource, thorium, offers controlled energy release through fission with a million-to-one energy density of hydrocarbon bonds. “Until 1939, we had no idea that we could release the energy that was stored billions of years ago in the nuclear structure of thorium and uranium. Now we realize that this stored energy might be the greatest and most valuable of all energy sources,” urges Sorensen.
In discussing liquid fluoride thorium reactor (LFTR) technology with Sorensen, it is hard not to get swept up in his true admiration for this powerful resource. Indeed, the more you learn about thorium and LFTR technology, the more you realize its extensive attributes including safety, economic viability, environmental and nonproliferation advantages, just to name a few. An understanding of these attributes, however, requires a baseline understanding of the technology. The key distinguishing factor for Flibe Energy is that their liquid-fluoride reactors use a chemically stable liquid fuel form based on fluoride salts of lithium and beryllium. These salts have exceptional chemical stability and a tremendous heat capacity, allowing for high temperature operation at low pressures. What this means is that these salts are liquid stable under a temperature range that spans a thousand degrees, making them a nearly ideal medium for sustaining nuclear reaction. A feed of fertile thorium is used in conjunction with an initial charge of fissile material to perpetuate the self-sustaining conversion of thorium into nuclear fuel. The reactor is designed so that thorium can absorb neutrons released by fission in the core to produce uranium-233. The uranium-233 derived from the thorium is fed back into the reactor core to continue fission to produce high heat for electricity generation and to perpetuate the conversion of thorium into uranium-233.
Thorium: Fuel for America’s Power Addiction
The United States economy is highly dependent on affordable and reliable electricity. Simply put, Americans want it all—an endless supply of clean, sustainable energy without any negative impacts. The mere mention of nuclear energy, however, typically conjures up emotionally charged images from recent events. And even people who have no particular opinion about nuclear generation know something about the concerns relating to production of nuclear waste that results from use of low-enrichment uranium (LEU) in solid-uranium-oxide-fueled light-water reactors (LWR). In conventional LWRs, solid-oxide fuel rods are irradiated for a period of three to four years until the fuel rods can no longer sustain irradiation. These “spent” fuel rods still retain the majority of their original fuel and include high levels of transuranic waste, yet are not currently reprocessed; rather, they accumulate in dry casks at the reactor site pending eventual disposal in deep geological repositories.
In contrast, “an LFTR power plant would generate 4,000 times less mining waste (solids and liquids of similar character to those in uranium mining) and would generate 1,000 times to 10,000 times less nuclear waste than an LWR. Additionally, because LFTRs can be designed to burn nearly all of their nuclear fuel, the majority of the waste products (83 percent) are safely stabilized within 10 years, and the remaining waste products (17 percent) need to be stored in geological isolation for only about 300 years (compared to 10,000 years or more for LWR waste),” says Sorensen.
LFTR technology could further be used to reprocess and consume the unused fuel remaining in spent nuclear stockpiles and to extract and commercialize many of the other valuable fission by-products that are deemed hazardous waste in their current form. The statistics of usable fuel sitting off to the sidelines in spent nuclear fuel stockpiles are staggering. According to Sorensen, “The U.S. nuclear industry has already allocated $25 billion for storage or reprocessing of spent nuclear fuel, and the world currently has more than 340,000 tons of spent LWR fuel with enough usable fissile material to start one 100 MWe LFTR per day for 93 years.” And, these numbers don’t even include the energy that could be produced from existing uranium and plutonium weapons stockpiles.
“Thorium and the fluoride reactors present an entirely different approach to fuel management that makes repeated recycling not only easy but economically advantageous,” says Sorensen. “LFTR is an inherently safe, intrinsically stable and self-regulating design that removes the root causes of today’s reactor accidents.” The LFTR system operates at near atmospheric pressure, making pressurized release, depressurization or explosion impossible. The reactor is further self-stabilizing because when the reactor gets hotter, its ability to generate heat goes down. Conversely, when the reactor is cooler, its ability to generate heat goes up.
LFTR technology is far more fuel efficient when compared with solid-oxide uranium reactors, and its high temperature operation enables use of more efficient power conversion systems. The combination of nearly complete fuel utilization and higher efficiency power conversion allows LFTRs to achieve energy production efficiencies on the order of 200 times that of a typical uranium reactor. “This significant efficiency gain translates to the equivalent of 4.11 million barrels of crude oil per year—more energy than that generated by a uranium reactor with a conventional steam conversion system,” stresses Sorensen.
Capital costs are also lower compared to solid-oxide uranium reactors. These cost savings are due to the smaller reactor and turbo-machinery size, low reactor pressures, minimal redundant safety systems and abundant supply of thorium. According to the U.S. Geological Survey’s 2006 Mineral Yearbook, the United States is estimated to have 300,000 tons of thorium reserves—about 20 percent of the world’s supply—of which more than half is readily accessible. “Considering only the readily accessible reserves, this national resource translates to nearly 1 trillion barrels of crude oil equivalent—5 times the entire oil reserves of Saudi Arabia. In addition to naturally occurring reserves, the United States currently has a reserve of 3,200 metric tons of processed thorium nitrate buried at a test site in the Nevada desert. This reserve alone is roughly equivalent to 21 billion barrels of crude oil equivalent when used in an LFTR with only minimal processing effort,” says Sorensen.
Remarkably, there are still more benefits to using thorium in a LFTR. It can produce a spectrum of radioisotopes for use in medical treatment, and rare isotopes needed to power NASA’s deep space exploration probes. In particular, the LFTR process produces widely used medical imaging isotopes from fission and promising targeted alpha-therapy agents from the decay of the thorium-derived uranium-233. The vast majority of the radioisotopes currently used for medical treatment have half-lives of only a few days and must be produced weekly to ensure continued supply. Because of the liquid fuel form, these and other useful by-products can be continuously removed from the fuel salt, even while the reactor remains online. Notably, the lone North American reactor currently providing these medical radioisotopes is scheduled to be retired in 2016.
If LFTR is so great, why aren’t we doing this already? According to Martin, the obstacles aren’t scientific, they’re institutional, political and business related. Martin further explains that “we’ve never done it before” is not a sound argument against LFTR development. If that were a real argument, then we wouldn’t have ever built any nuclear facilities. The natural gas boom is not going to last forever, and natural gas alone is not the way to build a low-carbon energy system. For this transition period, he argues, natural gas with nuclear is the way to go. In the last chapter of his book Martin walks through the economics of achieving 50 percent of our existing electric generation capacity with LFTR technology. In short, the market limit is directly related to how many units can be built and how fast. In the real world this means that limits on output capacity will likely be more closely related to regulatory, finance and insurance hurdles as opposed to other challenges such as access to thorium for fuel.
According to those involved with the thorium revival, it is an ideal energy source, and the timing to develop markets for thorium power is now. Thorium is abundant and distributed worldwide throughout the Earth’s crust. The initial problem, however, is getting LFTR technology to market in the United States. “You likely have to do it in-line with Flibe Energy’s vision,” says Martin. The transition to low-carbon energy production will have to take place incrementally. Coal-fired plants cannot just be shut down with a switch and abandoned—they need to be decommissioned. A first step is to stop building coal-fired generation and add new capacity with natural gas and thorium-based nuclear plants. The next step is to phase out the existing coal-fired infrastructure with new low-carbon baseload energy from thorium.
If we take these first steps, the United States can still lead the world in LFTR technology. The United States originated molten salt reactor technology, but if we delay while China spearheads its commercialization, we will be left behind. “The natural gas boom is having and is going to have real economic benefits. Simply being the low-cost energy provider to the world, however, is not a formula for long-term economic success. The next energy technology needs to be led by the United States,” urges Martin. Thorium may well become one of the world’s primary energy sources. The question is whether the United States is ready to seize the opportunity to position itself as the leader of the thorium transformation.
Kelly de la Torre is an attorney who understands the solutions that advanced energy can bring to the military, the U.S. government and our nation. She is working to bring together partners from various industry sectors and government to identify barriers to implementation and encourage dialogue and consensus on industry solutions. To find out about ALG | Attorneys and how ALG can help bring your company’s energy solutions to these discussions contact or Kelly de la Torre at 720-536-4600 or go to www.antonlaw.com.