EIGHT
NUCLEAR’S NEXT GENERATION
Seth Grae was a young New York lawyer, active in the movement opposing the proliferation of nuclear weapons, when he met an aging Israeli scientist preaching a new nuclear gospel. The year was 1991. A young achiever determined to make his mark in the East Coast establishment, Grae held four degrees, including a law degree from American University, a master’s in international law, and an MBA from Georgetown. Fresh out of law school, he represented dissident nuclear scientists from the Soviet Union. He helped craft international regulations to control the export of nuclear materials from China and the former Soviet Union, and he consulted with the government of India—which had never signed the Nuclear Nonproliferation Treaty (NPT) and, before the landmark 2006 agreement with the United States, was still a nuclear renegade—on both nuclear arms and nuclear power.
By the early 1990s, though, Grae found himself at loose ends. He “was a bored associate at a Manhattan law firm,” according to a Washington Post profile, “spending his days on a grab bag of international business clients ranging from video game startups to cement companies.”1 Through his contacts in the arms-control community, he encountered Alvin Radkowsky, an American-born Israeli citizen who’d worked for many years on naval nuclear reactors. A nuclear scientist every bit as accomplished as Alvin Weinberg, Radkowsky had been deeply involved with thorium for more than four decades.
As the chief scientist for the Navy Reactors Branch, Rickover’s fiefdom, Radkowsky led the design of the first full-scale commercial nuclear power plant in the United States, at Shippingport, Pennsylvania. He was also a protégé of Edward Teller. The personal history of the father of the H-bomb intersects the thorium story at unexpected angles. Radkowsky studied under Teller at George Washington University in the 1940s. Teller recommended Radkowsky to Rickover, when the latter was building his reactor corps and Radkowsky was a civilian nuclear physicist for the postwar Navy. Radkowsky was among the few members of the Nautilus team who did not attend the Oak Ridge school. He didn’t need to. He was already one of the foremost U.S. experts on reactor design and the nuclear fuel cycle. At some point, like Wigner and Weinberg, he became fascinated with thorium. When Rickover decided to build a dry-land prototype for the aircraft-carrier reactor project, he picked Radkowsky to head it up. And in Shippingport, Radkowsky saw the opportunity to prove his theories about thorium as an improved nuclear fuel.
The Shippingport Atomic Power Station first went critical in December 1957 and produced energy for the Duquesne Light Company for 25 years. It occupies a unique position in the history of nuclear power. It was considered the first full-scale nuclear power reactor with no military use: all it did was produce energy. For the thorium movement it’s like the Sputnik space capsule: it proved that something that had never been done could be done. Though it was a light-water reactor, it operated as an experimental breeder reactor, designed to produce more fuel than it consumed. And for several years, beginning in 1977, it ran on a blend of uranium and thorium, transmuting Th-232 to fissile uranium-233. After the reactor was shut down in 1982 and a detailed analysis of the core was run, it was determined that the core contained slightly more fuel than it started with. Shippingport proved that you could use thorium as an inexpensive and safe nuclear fuel in a light-water reactor and that you could breed additional fuel with it. This was not alchemy, but it was close. It’s still the only commercial reactor to operate over a long period of time on thorium fuel.
Paradoxically, though, Shippingport’s success contributed to the narrowing of the options for the young nuclear power industry. Despite the triumph of the thorium breeder experiment, Shippingport’s largest effect was to hasten the triumph of uranium-based LWRs: “The momentum it gave to light-water technology was enough to ward off incursions by competing technologies,” Weinberg wrote; its success channeled R&D into “a single line of reactor development” that would lead to the stagnation of the nuclear power industry.2
In 1972 Radkowsky, the principal designer of the Shippingport plant and the driving force behind the thorium breeder experiment carried out there, retired from the Navy and emigrated to Israel, where he taught at Tel Aviv University. But he never stopped thinking about thorium. In 1983 Teller, who never publicly recanted his support for nuclear arms, contacted his former student and urged him to restart his thorium work and create a new fuel design that would be less likely to contribute to the proliferation of nuclear weapons. Radkowsky was 68. It took him eight years, but he eventually patented an updated version of Shippingport: a design for a reactor core that combines a “seed” of low-enriched uranium rods, to ignite the fission reaction, and a “blanket” of thorium rods that would breed fissile U-233. In 1992, patents in hand, he founded a U.S. company called Thorium Power Ltd., based outside Washington, D.C., to build thorium reactors and to fulfill the vision he’d first had back in the 1950s: a world run on inexpensive energy from thorium. Radkowsky hired Grae to be his corporate counsel and operations man.
In Radkowsky’s seed-and-blanket design, fuel rods of uranium oxide are surrounded by a blanket of outer rods made of thorium and uranium dioxide. The uranium starts a chain reaction that bombards the thorium with neutrons; some thorium atoms capture those neutrons, converting the thorium to protactinium, which spontaneously, instantaneously decays into U-233—prolonging the reaction and producing heat and, in turn, electricity. In theory it’s a reactor that will need refueling only every 30 years or so and will produce only minimal amounts of toxic waste.
Conventional uranium reactors typically produce 50 to 60 megawatts per kilogram of fuel; thorium-based plants can achieve a rate of 100 megawatts per kilogram, using up a much larger fraction of the energy available in a given unit of volume. The melting point of thorium is about 500 degrees Celsius higher than that of uranium, and thorium reactors—even solid-core ones—are inherently safer. Finally, the core has a longer life: a thorium blanket can sustain a reaction for many years, while uranium rods must be changed out every three years or so.
“Alvin’s vision was to advance thorium-based fuels, based on earlier concepts used at Shippingport, with new designs that could be used in the current generation of nuclear power plants,” Grae told me. He is now the CEO of Lightbridge, the new name adopted by Thorium Power in 2009. This unlikely duo—an aged American Israeli scientist and a young lawyer—set out to change the power industry based on solid fuel thorium technology.
Radkowsky died in 2005, a year before Weinberg’s death. Thorium Power went public in 2002. On its advisory board is Hans Blix, the former director general of the International Atomic Energy Agency (IAEA) and the chief U.N. weapons inspector for Iraq from 2000 to 2003 (he’s best known to Americans for contradicting the Bush administration’s claims about Saddam’s weapons of mass destruction). The chair of the board is Thomas Graham, a long-time nuclear arms diplomat who served as President Bill Clinton’s special representative for arms control. Company officials are fond of the automotive analogy: “We’re just trying to replace leaded fuel with unleaded,” Grae likes to say. “You don’t have to replace your car engine or build new gas stations. You just replace the fuel.”
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WHEN I FIRST STARTED REPORTING on the thorium movement—in other words, before I’d heard the full LFTR gospel from Kirk Sorensen—I figured that Light-bridge, née Thorium Power, would be the story. It didn’t turn out that way. In fact, according to the true thorium believers, Lightbridge is something of a bastard child, a halfway measure that would neither rid the industry of the evils of uranium nor fulfill the true promise of thorium. As it turns out, Lightbridge itself has moved in other directions.
Certainly things looked promising at the outset. The company’s timing was ideal: in the early 1990s, with the collapse of the Soviet Union, a whole class of nuclear scientists and technicians were basically tossed out on the street, with little means of support and plenty of incentive to traffic both their skills and any illicit wares they might have stashed away—a situation that the U.S. government, for obvious reasons, found unacceptable. Thus was born the Initiatives for Proliferation Prevention, which amounted to a make-work program for out-of-work Soviet weapons scientists. For several years in the mid-1990s thorium power benefited from federal grants to conduct research at the Kurchatov Institute—named for Igor Kurchatov, who led Stalin’s weapons program, and often referred to as the Los Alamos of Russia. In the spring of 2009 Lightbridge signed a contract with Krasnaya Zvezda (Red Star), a government-owned nuclear design agency, to carry on testing and commercialization of the thorium fuel cycle. Thus, a U.S. company founded by an Israeli citizen is trying to develop the nuclear fuel of the future at a Cold War institute in Putin’s Russia. So proceeds the globalization of nuclear power.
In March 2009 Lightbridge researchers for the first time successfully tested one-meter rods in the experimental reactor. Commercial rods are typically 3.5 meters long; Lightbridge would still have to scale up to that length to run its fuel in conventional reactors.
And then there’s the waste. And here things get complicated, as Andrey Mushakov, a Russian economist and head of Lightbridge’s international operations, explained to me at a whiteboard in the company’s McLean, Virginia, headquarters outside Washington, D.C. Spent fuel from solid fuel thorium reactors contains both uranium and plutonium, and it’s highly radioactive. However, the volume of fuel is reduced by about half, and it has a far shorter half-life: it takes spent thorium fuel about 800 years to decay to an environmentally safe level of radioactivity, compared with 10,000 years with used rods from conventional reactors. You could reprocess the spent fuel into fuel for more reactors, although that’s not an avenue that Lightbridge is pursuing, for now.
And if the seeds were made of plutonium from old nuclear weapons (or from nuclear waste from civilian reactors) instead of uranium, then thorium could theoretically create electricity while disposing of old nuclear weapons.
You could also, in theory, refine used thorium fuel into weapons-grade material. In fact, spent fuel from a Radkowsky reactor is actually hotter, radioactivity-wise, than conventional uranium fuel. That makes handling it (for would-be bomb makers or for legitimate stewards) more tricky.
But the uranium and plutonium in spent thorium fuel is denatured, that is, it’s contaminated with useless isotopes, making it much more difficult to wring bomb fuel from it. If you’re a bomb maker, you’d be better off just buying natural uranium on the open market and building an enrichment facility.
That’s the technology. The business side is less promising: traded over the counter, Thorium Power stock languished below one dollar for many months in 2008–2009. Then its board reduced the number of shares outstanding and changed the company’s name to Lightbridge. With those financial moves came a shift in business direction. Since then, Grae has developed a lucrative business in consulting gigs, such as the one with the United Arab Emirates (UAE) that brought in $6.4 million in revenue in 2010.
These days Grae spends most of his time in Abu Dhabi; he would call me from his offices there for our phone conversations. The UAE has become a testbed for the nuclear renaissance, and it might become a model for how nuclear power can be done right. Blessed with about a hundred billion barrels of oil, the UAE government has decided it would rather export the oil to more petroleum-hungry countries and get its own energy from sustainable sources, like solar (the desert nation has one of the most aggressive solar development programs in the world) and nuclear. With Grae’s guidance the country signed an extensive agreement with the IAEA that allows for unannounced inspections and calls for the UAE to import nuclear fuel and send it elsewhere when it’s spent. The UAE will never own nuclear fuel, just lease it. In so doing the UAE will become the first nuclear-powered country to voluntarily give up the enrichment of uranium and the reprocessing of plutonium, effectively eliminating its ability to make weapons.
It could also become the first country to build its commercial nuclear power industry around thorium—although for the moment UAE officials consider that a long-term solution. For now Lightbridge is helping the emirates build a uranium-based nuclear sector, which somewhat dims the luster of Lightbridge’s thorium power ambitions.
The hiring of Jim Malone, the former vice president for nuclear fuels at Exelon, did not exactly confirm Lightbridge’s thorium commitment, either. A veteran member of the nuclearati, Malone spent a decade at Exelon, the largest U.S. producer of nuclear power. When I spoke with him and Grae in August 2011, they made it clear that, while thorium fuel development remains a part of Lightbridge’s plans, it is no longer necessarily the company’s highest priority. In fact, Lightbridge was working on two other fuel elements, both based on uranium, one an all-metal variety. The company still hopes to make its thorium fuel technology commercially viable, but it will be mainly targeted at countries (like India) that lack extensive uranium reserves. “We don’t choose among our children,” said Grae—meaning that, as far as Lightbridge is concerned, the market will choose among thorium and uranium fuels.
In any case even Lightbridge’s original thorium goals were too modest for thorium’s true believers. Replacing uranium with thorium in conventional reactors, they say, is a half measure, like putting biofuel in a Hummer. What’s needed is not just a new fuel but a new engine. The Lightbridge story is emblematic of the thorium movement as a whole: great technological promise dampened by the realities of today’s nuclear market. Over and over I heard the same refrain: To carve out a place in the nuclear power industry, thorium must do more than offer the same performance with greater safety and fewer proliferation possibilities. It must be better. To see whether that can be true, it is necessary to compare new thorium reactors with the plans for future advanced reactors based on uranium.
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THE SUMMER MEETING OF THE American Nuclear Society (ANS), held at a seaside resort in Florida in late June 2011, could have been a wake. It was three months after Fukushima. The nuclear power industry worldwide had lost the exuberance of the so-called nuclear renaissance of recent years, which saw plans for dozens of new reactors, costing billions of dollars and producing zero carbon emissions, to be installed worldwide. Nuclear power was being questioned and reassessed internationally, and three Western European countries— Germany, Switzerland, and Italy—had publicly announced that they would give up on it altogether and shut down their reactors. Two of the best-attended sessions at the ANS conference dealt not with new builds but with a lugubrious subject: lessons learned from Fukushima.
Shares in nuclear suppliers like Toshiba, owner of Westinghouse Electric Corporation and one of the major nuclear reactor vendors in the world, plummeted on the first day of the Fukushima disaster and had not recovered by the time of the conference. According to the antinuke website Nuclearbailout.org, the formerly resurgent industry had suffered eight defeats in state legislatures in 2011, including efforts to rescind nuclear moratoria in Wisconsin, Minnesota, and Kentucky—and no victories. On the surface it seemed a lousy time to be a nuclear power company.
Those clouds, however, masked a dawning technological revival in the nuclear power industry—one that could reshape the global power sector before 2022 as big nuclear suppliers like Toshiba and the French giant Areva, and major uranium miners like Cameco, bring long-awaited new reactor designs to market. Simply put, what happened at Fukushima may have slowed down the transition to new nuclear reactor technology, but it also made it more inevitable.
Fukushima, Kirk Sorensen told me, “marked the death of conventional light-water reactors.” Evolutionary designs that utilities assumed would carry lower risks now faced regulatory hurdles raised by post-Fukushima fears, while more innovative reactors continued to move forward toward licensing and installation. Fukushima was like the devastating asteroid strike that, according to many paleontologists, doomed the dinosaurs and gave rise to the age of mammals.
To get a sense of where the nuclear power industry stands technologically, it’s important to consider that the reactors at the Fukushima-Daiichi plant were designed in the 1960s. Fukushima No. 1, a “Mark 1” model, went critical in 1971, the year before a report by the Atomic Energy Commission recommended that the Mark 1 be discontinued for safety reasons. While other industries have been transformed by new technology since the early 1980s, innovation in nuclear power essentially ground to a halt after the 1979 Three Mile Island accident. Eighty-five percent of the electricity from nuclear plants today is generated by Gen II reactors like the Mark 1. It’s as if nearly all the computers in use today were Altair 8800s, developed by Xerox in the early 1970s, except PCs don’t blow up and spread radioactivity across the countryside.
By 2011 the design level had finally started to change. Long-overdue Generation III designs were finally starting to come online, and companies like TerraPower were developing fourth-generation reactors, to be built between 2020 and 2030. Some suppliers were even touting Gen-III+ machines, which was a little like putting new whitewalls on a 1999 pickup truck and calling it a 2011 model.
That summer the Tennessee Valley Authority signed an agreement with the nuclear contractor Babcock & Wilcox to build six small modular reactors, the first small modular reactors contracted for commercial power generation. Ironically the site chosen for the small reactor project was Clinch River, the site of the ill-fated fast breeder reactor—a program that was outsized in every respect.
The government of France, meanwhile, announced plans to invest 900 million francs in nuclear power R&D, including thorium-powered systems.
The vast majority of Gen III and IV designs would run on traditional uranium fuel. Theoretically they’ll be less expensive to build and more efficient on a cost-per-kilowatt basis than conventional reactors, and they will produce fewer toxic wastes to be stored indefinitely. Some designs, which I describe in more detail later in this chapter, are marvels of ingenuity; it’s as if all the pent-up creative energy of reactor designers, stymied for decades, was released at one time. These designs could help bridge the way to the thorium-fueled future. “It’s time for a new generation of nuclear power,” declares a Westinghouse promotional brochure. Unfortunately, there’s no guarantee that the new generation will ever make it to market.
The only Gen III reactor to actually be certified to date by the Nuclear Regulatory Commission (NRC) is Westinghouse’s AP1000 machine. Based on a reactor certified in 1999 but never operated commercially, the AP1000 is the Ford minivan of reactors: simple, utilitarian, built for safety, and deeply conservative.3 Nothing about the core design or the fuel cycle is innovative. It has what Westinghouse bills as a “passive core cooling system,” which in theory will calm the reactor in the case of an accident, even if the operators do nothing. In theory, no electricity is required.
That all sounds pretty safe until you consider that the Fukushima plant had similar passive safety systems, and that, because the area had been so thoroughly contaminated, getting water to top off the cooling system became a major problem for weeks, not days. The AP1000 is basically a smaller, conventional light-water reactor with added passive safety systems. It’s a minivan with extra side-door airbags and a roll bar.
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LIKE OTHER SO-CALLED ADVANCED REACTORS planned by the industry, the AP1000 has hit bumps in the road to commercialization. Since Fukushima, environmental groups have petitioned the NRC to delay approval of the AP1000, a move that would put costly delays in the way of Southern Company and Scana Corporation, the companies building the new multibillion-dollar reactors. The effect of Fukushima is likely to be paradoxical: it could help kill off half measures and somewhat updated reactor designs like the AP1000 because investors won’t back them and the NRC, under the additional pressure of safety concerns, won’t license them. To gain licensing for and build new reactors today, you need not only an acceptable but not too innovative design, but also plenty of patience, and very, very deep pockets. The nuclear renaissance is a matter less of science than of dollars and cents.
That said, some new reactor designs could shove uranium-fueled reactors into the late twentieth century, at least, if not the twenty-first. And thorium-based machines are, according to the global nuclear power cognoscenti, among them. The Generation IV International Forum, a collaboration of a dozen governments (including China, Russia, France, Japan, and the United States but not India) plus the European nuclear agency Euratom, has whittled the competing technologies to six (from more than 100), ranging from tweaks to existing systems to altogether new machines. Most are either advances to existing technologies or updated versions of older reactors. Only one is truly radical. For purposes of comparison, I will briefly examine each technology and its advantages and disadvantages.
The sodium-cooled fast reactor. The most familiar fourth-generation machine is, as you might guess, based on liquid metal fast breeders such as the ill-fated Clinch River project or the French Superphénix. Despite the LMFBR’s checkered history, versions of sodium-cooled fast reactors are operating in Russia, South Korea, and India. According to Western analysts, China brought a prototype online in 2010.4 (The Superphénix, a 1,200-megawatt sodium-cooled fast breeder was the target of one of the most audacious attempted acts of nuclear terrorism in history when five rocket-propelled grenades were fired across the Rhone River at the plant on January 18, 1982. The damage was negligible. The perpetrator of the attack is said to have been the notorious international terrorist Carlos the Jackal.)
Sodium, which is essentially transparent to neutrons and so does not slow down the fission reactions, has excellent heat-transfer properties and can be used at lower pressures than other coolants such as water and gas. Russia has been running sodium-cooled fast breeders since the 1980s. Proponents claim that producing energy from sodium-cooled reactors could be safer and less expensive than existing light-water designs (there’s little proof of the first proposition and plenty of evidence against the second), and sodium-cooled reactors have the additional advantage of having actually been operated as commercial plants, not just as prototypes. “We really can build one,” the nuclear scientist Robert Hill, of Argonne National Lab, told the Economist. But the dismal record of liquid metal fast breeders makes the sodium-cooled fast reactor, which is a type of liquid metal reactor, a puzzling choice for the new generation of reactor technology.5
The gas-cooled reactor (GCFR). The second design not cooled by water in the Gen IV lineup is the GCFR, which, like the sodium-cooled machine, would be a fast-spectrum reactor. Pressurized helium in a gaseous form would both cool the core and drive a turbine. Helium gas is noncorrosive and can be used at high temperatures. GCFRs would have one other notable advantage: they can use a variety of fuels, including thorium. The ability to run gas-cooled machines as breeder reactors could help make them more economical and less apt to increase nuclear proliferation than today’s conventional systems; the increased efficiency means you need less fuel to produce a given amount of power.
No gas-cooled reactors have been operated on a commercial scale, though, and there is a historical irony to considering them for next-generation technology: the original design for the Hanford reactor, built to produce plutonium for the Manhattan Project, was a helium-cooled machine. Eugene Wigner called that high-temperature, helium-cooled machine “an engineering nightmare.” His concept of a water-cooled reactor won out, and water-cooled reactors have been the dominant design ever since. Returning to gas-cooled machines today would be like deciding that steamships are the wave of the future for ocean voyages.6
Lead-cooled fast reactors (LCFRs). In their early nuclear submarines, the Soviets used reactors cooled with a blend of lead and bismuth, and LCFRs have gained renewed interest, particularly in Europe, since the 1990s. Using molten lead, or a lead-bismuth mix, could facilitate the creation of smaller modular reactors with a long-lived (some even say lifetime) core. In theory, such reactors could be supplied, prebuilt, to nonnuclear countries without giving them access to weapons-grade nuclear material.
In December 2009 a joint venture called AKME Engineering, one partner in which is the state-owned Russian nuclear company Rosatom, was formed to build thousand-megawatt lead-bismuth fast reactors based on the original design for Soviet subs. A prototype is planned for 2019. Like all the fast reactor designs, however, LCFRs are complicated to build and hard to run. There is no conclusive evidence that they can be produced and operated on a commercial scale.
The supercritical water-cooled reactor (SCWR) and the very high temperature reactor (VHTR). These are two of the other so-called Gen IV reactors, simply light-water reactors with new twists. Obviously reactor designers like to use superlatives (supercritical, very high) to distinguish the newer technologies from their more dated siblings; the actual guts of the machinery, though, are not that much different.
Supercritical refers to a fluid at such a high temperature and pressure— “beyond the critical”—that it exists in a state that is neither liquid nor gas (or steam, in the case of water). Because small changes in pressure or temperature result in large changes in density, supercritical fluids can be finely adjusted to exhibit desired properties. Supercritical carbon dioxide, for example, is used to decaffeinate coffee beans. In the case of a nuclear reactor, supercritical coolant water can be used to drive a turbine directly, eliminating the need for a secondary heat exchange system. That elevates thermal efficiency to the 45 percent range from the 33 percent typical of conventional pressurized water reactors. Simplifying the plumbing also lowers costs: the Generation IV International Forum has estimated that a reactor cooled with supercritical water could be built for $900 per kilowatt of capacity—about a quarter of the cost of advanced Gen III reactors like the AP1000.
The high pressure needed to maintain water in its supercritical state, though, requires a thicker pressure vessel. With relatively little water in the core, a reduction in pressure (caused by a pipe break, for instance) could lead very quickly to a catastrophic coolant loss. What’s more, SCWRs will require the development of new alloys that resist cracking and corrosion—common problems in high-temperature reactors cooled with water, including the very high temperature reactor.
The VHTR is a bit of a gryphon, a mythical beast welded together from parts of the eagle and lion. Like the original X–10 pile at Oak Ridge, the VHTR would use graphite, rather than water, as the moderator and helium gas (as in the gas-cooled fast reactor) as the coolant. Other Gen IV designs attempt to close the fuel cycle through various forms of reprocessing and reuse of spent fuel; the VHTR is a once-through cycle that would do little to reduce the waste or the threat of proliferation posed by current light-water reactors. Nevertheless, in 2009 the Obama administration announced $40 million in R&D funding for the Next Generation Nuclear Plant project, which is based on the VHTR. Next generation, in nuclear power, is a fungible term. As of early 2012, thorium-based reactors were not part of the federal government’s next-gen nuclear R & D program.
All these are new and ingenious ways of solving old problems—the inherent problems of uranium-based solid fuel reactors. Nuclear engineers have spent a half century building ever more sophisticated systems that will essentially prevent uranium from doing what it wants to do—to open the floodgates a crack without washing away the dam, as it were. Proponents of LFTRs want to build machines that allow thorium to do what it wants to do. And, in fact, the molten salt reactor—championed by Alvin Weinberg, developed at Oak Ridge, and abandoned on the eve of the first energy crisis—is the final Gen IV design on the forum’s shortlist of competing designs.
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IN MAY 2011, AFTER I ATTENDED the third Thorium Energy Alliance conference in Washington, D.C., I dropped in on a meeting of the vaunted Blue Ribbon Commission on America’s Nuclear Future, known as the BRC, that was held in the basement meeting room of a downtown Washington hotel. The occasion was an update on the NRC’s responses to Fukushima and a review of the draft report from the Reactor and Fuel Cycle Technology Subcommittee, which was considering new approaches to the challenges of next-gen reactor design and waste disposal. Bespeaking the disfavor in which the nuclear industry still finds itself, renaissance or no, the meeting drew a few dozen spectators—some interested industry officials, some Hill staffers, a few reporters, and that was about it.
The BRC is one of those full-frontal Washington offensives that get announced with great fanfare and then tend to peter out in endless meetings, voluminous reports that no one but wonks ever reads, and few effective policy changes. It’s like a religious conversion: the mere fact of forming the commission, it was hoped, would produce a magical solution to the problem (specifically, in this case, the problem of nuclear waste; more generally, as the commission’s full name made clear, the future of nuclear power in the United States). In reality, the Blue Ribbon Commission was an attempt to reconcile two fundamentally opposed positions: the Obama administration’s strong support for nuclear power, in theory, as a primary source of carbon-free energy on the one hand, and its adamant opposition to the Yucca Mountain storage facility for nuclear waste on the other. By this time it was clear that Yucca Mountain would never be built. Without a place to store the spent fuel and toxic waste from conventional nuclear plants, the industry could not move forward. Appointed by President Obama soon after he took office, the BRC was supposed to be the sword that severed this Gordian knot. Although it was headed by the beltway eminences Lee Hamilton (former chair of the House Foreign Affairs Committee) and Brent Scowcroft, the former U.S. national security adviser, its edge was dull. By the summer of 2011 little had come of the BRC beyond a series of draft reports, and it looked as if no firm conclusions, much less a plan, would emerge before the end of Obama’s first term. The Blue Ribbon Commission was on its way to proving the old adage that the best way to kill an idea is to assign a committee to study it.
The meeting I attended took place almost exactly two months after the tsunami broke over the Fukushima-Daiichi plant. The session quickly devolved into a Laurel-and-Hardy skit, as an NRC bureaucrat named Lawrence Kokajko was grilled by the commissioners, particularly Hamilton, a man used to having bureaucrats tremble before him. Kokajko said that, at this time, the NRC had no information that “would cause us to doubt the safety of the current operating [reactor] fleet.” Hamilton wanted more specifics. Kokajko restated without answering. Much posturing ensued. It was like a reenactment of the entire history of nuclear power in the United States: plenty of hot air, a certain amount of power produced, and little real progress.
The only one whose performance came off well during the meeting was Per Peterson, a professor of nuclear engineering at the University of California at Berkeley.
I’d met Peterson at the Thorium Energy conference earlier that week. He is slender, with a high forehead, thinning dark hair, and piercing brown-black eyes behind rimless glasses. The lips of his thin mouth curl slightly upward at the sides, giving him the suggestion of a perpetual smirk. Brilliant and direct, he has the air of a man with a low tolerance for stupidity. Peterson chairs the Reactor & Fuel Cycle Technology Subcommittee of the BRC. He and his team of grad students have carried out several experiments related to advanced reactor design and thorium power, and Peterson has become something of a hero to the thorium movement. His work focuses on what’s known as the pebble bed advanced high temperature reactor (PB-AHTR), a machine that could provide a bridge to the LFTRs of tomorrow.
Based on two older technologies—coated particle fuel (pebbles) and coolants made from molten salt—PB-AHTRs offer the advantages of both molten salts and modular design that make them easier to manufacture, license, and site. The pebble-based fuel reaches full depletion (that is, it gives up all its available energy) in less than a year, meaning that demonstration reactors could test different fuel types much more rapidly than other designs. And PB-AHTRs, in theory, would use far less natural uranium and leave behind less spent fuel than today’s designs. As in LFTRs, the molten salt coolant is chemically inert and contained at low pressure, making Peterson’s design safer than light-water reactors.
“The economics are much better than current reactor technologies,” Peterson told me. Proving that high-temperature pebble bed machines would successfully produce commercial power would pave the way for thorium-based reactors. The link seemed somewhat tenuous to me, but having a mainstream physicist of Peterson’s stature—and his access to research funding—in its camp was a major coup for the thorium movement.
Peterson, however, is a realist. He had good news and bad news for the thorium fans in the audience: The bad news is that reactors that use new materials or new fuels will require multiple decades, at least in the United States, to be funded and licensed. The earliest that a commercial thorium-based reactor could come online, in Peterson’s view, would be 2032. That’s not soon enough to solve the energy crisis. And it’s not soon enough for thorium advocates like Kirk Sorensen, who wants to see a LFTR built before 2020.
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BESIDES LENDING THE BRC PROCEEDINGS an air of rigor and incisiveness they otherwise lacked, Peterson’s main task was to present the draft report from his subcommittee. To be included in the Blue Ribbon Commission’s final report, which was delivered to the president in January 2012, the Peterson report is as close as the United States is likely to get to mapping out a path forward for new reactor technology; while it was couched in the cautious idiom of official Washington, the draft echoed loudly the call for a second era of nuclear innovation. It even mentioned thorium several times. Specifically, the subcommittee called for a solution to the nuclear waste problem through a return to uranium recycling schemes, long abandoned in this country but a key element of nuclear power industries in France, India, and even Japan.
The events at Fukushima “underscored the importance of treating spent fuel management and storage as a central part of the safety regime,” Peterson and his team concluded. “Technological advances hold promise for improving the safety of nuclear energy systems—ensuring that this promise is realized must be a priority of U.S. nuclear policy, with respect to both RD&D [research, development and deployment] investments and deployment decisions.”7
The draft report called for “a major international effort, encompassing international organizations, regulators, vendors, operators, and technical support organizations,” to develop and operate safe nuclear power plants and safely manage nuclear wastes worldwide. Like Jim Kennedy and John Kutsch, Peterson and his colleagues also raised the specter of diminished U.S. competitiveness: “It is in our nation’s interest to retain [our] leadership role” in nuclear technology, the draft states, ignoring U.S. cession of that role back in the 1980s. “Regardless of one’s view of the nuclear industry’s near- and longer-term prospects more generally . . . there are countries planning to increase their nuclear energy investments—in some cases substantially—while other countries that currently lack nuclear energy infrastructure are interested in developing it.”8 Giving up on nuclear power would mean not only remaining dependent on fossil fuels but giving away any influence over the shape and spread of nuclear technology—both power reactors and weapons production.
There followed the predictable call for a “sustained, strategically targeted, and well-coordinated federal RD&D effort” to bring to market “game-changing” technologies that would accomplish the nation’s energy security as well as its economic and safety goals. Among those game changers, according to the subcommittee, is thorium: a thermal spectrum, high-temperature molten salt reactor using thorium could solve many problems associated with current “once-through” (lacking fuel recycling capabilities) uranium-based reactors. And then came the usual caveat: “Such systems could potentially offer many of the combined benefits of the alternatives listed. However, these systems have not received systematic study and the component technologies for these types of systems are less well developed.”9
To anyone familiar with the Molten Salt Reactor Experiment at Oak Ridge in the 1960s, the suggestion that “these systems have not received systematic study” is laughable. Many millions were spent, thousands of hours were put in, and reams of studies and results were produced in the systematic study of thorium-based MSRs. To be sure, much more has been carried out on fast breeders, which remain near the top of the lists of Gen IV reactors (and which are cited in the Peterson report as one of three “representative advanced nuclear energy systems,” along with once-through high-temperature reactors and modified light-water machines—a discouraging representative sampling). It could be argued that the net result of the fast breeder programs has been much less encouraging than the study of MSRs.
Peterson himself is familiar with this history. His committee’s report is a valiant effort to shift the discussion of nuclear power away from fear and rhetoric and toward the future. The cautious language of official scientese, though, meant that thorium could receive no more than an obligatory mention in the report of his subcommittee. The most important recommendation from the reactor and fuel cycle report was to reshape the NRC to make it capable of operating effectively in a Gen IV world: “We concluded that a portion of the federal government’s nuclear-energy R&D investment should go to the NRC and be directed for work to develop a regulatory framework to perform supporting, anticipatory research for advanced reactors and fuel cycle technologies significantly different than those we use currently,” Peterson explained to me in an email. The portion he had in mind was not large: 5 to 10 percent. The report does not spell out what, exactly, would constitute “anticipatory research.”
Clearly, the federal technological bureaucracy has not progressed far from the days of Milton Shaw and WASH-1222. In the reactor and fuel cycle technology report, thorium was basically an afterthought, as it has been since the beginning of the Atomic Age. Until a new generation of nuclear technologists and executives rises to places of authority in the industry, there’s little prospect of that changing.
Take a step back, though—and get out of Washington—and the picture resolves into a wider pattern. Not only are many countries and companies aiming to solve the energy crisis using thorium as the basis for the twenty-first-century nuclear power industry, but the movement toward liquid-fueled thorium reactors forms the next, and perhaps the ultimate, advance in the centuries-long quest for safe, sustainable, and efficient forms of energy. This search has two parallel streams: the progress from solid to liquid forms of fuel, and the elimination of waste products.
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THE BIRTH OF THE MODERN ERA OF HYDROCARBONS is usually traced to 1859, when Colonel Edwin Drake drilled the first oil well in North America, at Titus-ville, Pennsylvania, or a bit further, to 1848, when the first modern well was drilled near Baku, Azerbaijan, on the Caspian Sea by the Russian engineer F. N. Semneyov. In fact, though, humans’ fascination with, and search for, “the magic liquid” goes back more or less to the dawn of recorded history. Bitumen, the viscous form of petroleum, was tapped in Mesopotamia as far back as 3000 B.C. In the Iliad the Trojans poured “unwearied fire”—a weaponized form of liquid petroleum—on the Greeks’ ships, causing “a flame that might not be quenched.” The gas seeps found commonly across the Middle East fueled permanent flames, helping to create the fire-worshiping cults that Moses abominated. Used by the Byzantines in the countless wars of the Dark Ages, oleum incendiarum (Greek fire) was an early form of the ultimate destructive weapon, the atom bomb of its time.10
A simple insight underlay the fascination: liquid fuel is more efficient, more transportable, easier to build into machines, and more dense in terms of energy per unit of volume than solid fuel. From the time people first began systematically using fire for heat, illumination, and cooking, 300 or 400 millennia ago, they have sought ways to make it easier to use. It did not take great ingenuity to realize that liquid forms of flammable fuel were better than solid ones, whether you were carrying them across the desert or heaving them at enemy ships. From burning branches to charcoal to coal to petroleum, the march of civilization is also the progressive compaction and liquefaction of primary fuels.11
With the discovery of the boundless energy at the heart of the atom, that progress seemed to have reversed. Solid enriched pellets of uranium were the most energy-dense forms of matter ever known. What need is there to use liquid fuels (petroleum) when you have such a marvelously compact (and relatively lightweight) source of energy as the uranium atom?
Plenty, as it turns out. In chapter 3, I listed the advantages of liquid nuclear fuels over solid ones. Most of those advantages apply to fossil fuels as well. You can’t fly a jet with coal. You can launch a rocket using solid fuel; the defunct space shuttle program used solid fuel to boost the rocket into orbit—a stage that requires huge amounts of thrust, rather than efficiency, and no throttle capability—and liquid fuel once in orbit, to enable more efficient and flexible power. Once you start up a solid fuel booster, you can’t shut it down: it continues to burn until the fuel is consumed. That’s a familiar scenario to anyone who has ever been faced with cooling off a runaway solid-core uranium reactor.
Whether the fossil fuel is solid or liquid, though, you still have the problem of waste. Coal plants leave behind coal ash (which is more radioactive, ounce for ounce, than nuclear plant waste), and huge amounts of carbon are emitted into the atmosphere (a typical coal plant generates 3.7 million tons of CO2 a year, according to the Union of Concerned Scientists); liquid petroleum, natural gas, and gasoline are only slightly cleaner. The same goes for solid-core uranium reactors: as the Yucca Mountain debacle demonstrates, the issue of nuclear waste is the single biggest obstacle to the renaissance of nuclear power in the United States, from a perspective concerned about waste storage and the proliferation of nuclear weapons. Liquid fuel reactors, specifically LFTRs, show the greatest promise for overcoming the waste dilemma. Thorium advocates, in fact, say that LFTRs will essentially eliminate the nuclear waste problem altogether.
As you might guess, the situation is not quite so simple. Understanding it fully requires reviewing the origins and makeup of nuclear waste. To do so I return to a familiar figure in this story: Eugene Wigner.
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THE MOST PROBLEMATIC LONG-TERM NUCLEAR WASTE is the transuranic elements. Created in the reactor’s nuclear forge, the core, transuranics are simply elements beyond uranium—their atomic numbers are higher than that of uranium, number 92. None of these elements occurs in nature in more than trace amounts. The one that is most important in controlling the spread of nuclear weapons is plutonium-239. Often referred to as the deadliest substance on Earth, it is no more toxic than many substances routinely produced by industry every year, including the by-products of radon gases. With a half-life of only 24,200 years, though, plutonium is intensively radioactive. About ten kilograms of nearly pure PU-239 are required for a single nuclear weapon. The spent fuel from nuclear reactors is contaminated with other, lesser isotopes of plutonium (PU-240, PU-241, and so on), which are difficult to separate from the desirable plutonium-239. Still, with its potential for bomb making and its capacity to poison humans when inhaled at low doses, plutonium lies like a dark fruit at the end of a series of transmutations undergone by uranium.12
A thousand-megawatt light-water reactor produces about 290 kilograms of plutonium a year. Total world production of reactor-grade plutonium is about 77 tons a year; approximately 1,510 tons have been produced to date. You can buy it from Oak Ridge if you have the right qualifications and clearance, which in practice eliminates nearly everyone. (“Volume discounts available,” the ORNL website exclaims.) Since we started creating it in the early 1940s, plutonium has frustrated every attempt to dispose of, cease production of, and wish it away. It is the distilled essence of militarized nuclear power, and its malign influence can be felt behind every decision made in the industry since the 1950s.
The other type of radioactive waste, fission products, was first understood by Eugene Wigner, who explained the early failure of the X-10 reactor at Oak Ridge under the Manhattan Project by predicting that the fission reaction was being poisoned by the buildup of xenon-135, which has a high capacity to absorb neutrons. As xenon accumulated in the reactor, the rate of fission reactions slowed, and eventually the chain reaction fizzled out. This problem was solved in the X-10 by simply adding more fuel rods. However, the buildup of xenon and other contaminants eventually ruins conventional solid uranium fuel rods; that’s why they must be replaced after only a small percentage of the uranium is consumed (less than 1 percent of the uranium that is mined is fissioned in today’s reactors). Uranium reactors are self-defeating: the fission products eventually contaminate the fuel so that it must be removed and replaced, requiring the reactor to be shut down and creating spent fuel rods that must be safely stored for many millennia.
The real threat of fission products is not in the reactor, of course: it’s in the environment, where high-level wastes remain radioactive for thousands, in some cases millions, of years; these must be shielded to prevent radiation from poisoning the environment. The amount of high-level waste worldwide increases by about 13,230 tons a year; that number will rise sharply in coming decades if predictions for new reactors prove close to being accurate.
As I’ve noted, several countries, including France, Japan, and Russia, now have active reprocessing programs to remove the fission products and convert spent fuel to reusable fuel elements. Reprocessing converts the waste into a form appropriate for permanent geologic disposal while recycling the useful unburned fuel back into reactors. Another significant conclusion of Peterson’s Reactor and Fuel Cycle Technology Subcommittee was that the reprocessing of spent fuel—abandoned in the United States under President Gerald Ford in the 1970s—should be a part of any future nuclear power scenario. Reprocessing nuclear waste would dramatically reduce the amount of new waste added to our already huge pile of radioactive waste (most of it stored, as at Fukushima-Daiichi, in spent fuel pools at nuclear power plants). One problem with this scenario is that, because uranium has been so inexpensive (and, as a percentage of operating costs, such a minuscule expense for nuclear power producers), there’s little market incentive to recycle spent fuel. Since no politically acceptable solution for storing spent fuel is on the horizon, though, reprocessing is an absolute requirement for a new nuclear era in the United States.
Most Gen IV reactors are billed as closing the fuel cycle, that is, they include some form of fuel recycling. Fast breeders are considered especially useful for this because, with their overabundance of neutrons, they can consume less-than-ideal fissile materials. Reprocessing, though, comes with its own set of disadvantages, one of which is that it’s like a pyramid scheme: it requires more and more infusions of cash (in the form of energy) to produce diminishing returns.
“It might take three reactors to create enough fuel to be recycled to fuel one reactor, and less and less each generation,” Sorensen explains on the Energy from Thorium blog. “It’s a losing game (which is why the nuclear industry is always trying to tell you about the brave new world of fast-spectrum reactors).”13
Thorium advocates argue that thorium essentially solves the problems of waste storage and proliferation because the total volume of spent fuel is smaller (thanks to thorium’s more favorable burn-up profile), the proportion of high-level wastes requiring long-term storage is smaller, and the length of time they must be sequestered is shorter as well. However, thorium-based solid fuel reactors do produce plutonium. And their remainders are actually even more radioactive than the spent fuel from a conventional reactor. Paradoxically, that’s a good thing: it makes handling the wastes, and building bombs from them, more hazardous than doing so with the waste from conventional reactors. This is the subject of hot dispute. To summarize the arguments, I’ll step back and review the most common objections to thorium power.
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IN REPORTING ON THE THORIUM POWER MOVEMENT, I heard plenty of reasons why it would never work. After a year or so I classified them into three categories: market barriers, challenges related to waste and proliferation, and what I came to call the traditionalist argument.
The market-based argument is simple: the nuclear power industry has a fuel today that is abundant and inexpensive. Why should it switch to a new, relatively unproven fuel? These assumptions are faulty (uranium may well not be inexpensive and plentiful much longer—see the comments of Srikumar Banerjee, chair of India’s Atomic Energy Commission, from chapter 7). More important, this argument does not take into account the broader costs and risks of uranium-based nuclear power, which have been highlighted by the Fukushima-Daiichi accident. There’s little chance of nuclear power’s fulfilling its promise until those costs are driven down—by shifting to thorium power.
The waste and proliferation issues are more complicated, and I will break them down into four elements.14 In distilled form they sum up the objections to thorium from both the nuclear establishment and antinuclear groups.
1.The use of enriched uranium or plutonium in thorium fuel to ignite the fission reaction carries proliferation risks, and U-233 is as useful as Pu-239 for making nuclear bombs.
This is the central claim of those who dismiss thorium’s prospects for reducing the nuclear waste stream: Solid-fuel thorium reactors produce both U-233 (the fissile daughter element of Th-232) and plutonium, so what’s the difference? What’s more, thorium reactors require low-enriched uranium or plutonium to initiate the fission reaction, thus creating more material that can be refined into bombs.
The kernel of truth here is that the U-233 (and thus the plutonium as well) created in the transmutation of thorium is contaminated by U-232, one of the nastiest isotopes in the universe. With a half-life of less than 70 years, U-232 decays into the radioisotopes bismuth-212 and thallium-208, which emit intense gamma rays that make it very, very hard to handle and transport (not to mention reprocess) and that would very likely destroy the electronics of any weapon into which they were built. Theoretically, it’s possible to make a bomb with U-233, but plutonium is much easier to make and does not come with the problematic U-232. Militaries will always opt for plutonium and U-235, because they can’t afford to expose their personnel to the deadly risks of U-232. As for terrorists, they’d be better off simply buying natural uranium on the open market and finding a way to enrich it. The United States reportedly tested bombs with U-233 cores in the late 1950s, but no country has ever included it as a material as a part of its nuclear weapons program. It’s useless even for the most zealous of hypothetical suicide bombers, because they’d probably never reach their target.
2.Most proposed thorium reactors require reprocessing to separate out the U-233 for use in fresh fuel. As with conventional uranium power plants that include reprocessing, bomb-making material is separated out, making it vulnerable to theft or diversion.
This is a tired canard. Never mind that every nuclear fuel cycle currently in production or contemplated generates “bomb-making material”—this statement ignores the realities of weapons building. Most Gen IV designs described in this chapter involve fuel recycling; indeed, as the Peterson report stated, recycling is critical to the future of nuclear power. To be sure, reprocessing spent fuel rods from a solid fuel thorium reactor is not a simple matter, whether you’re making bombs or new fuel. But it’s important to note that, as with all these arguments, external reprocessing is necessary only for solid fuel reactors—not LFTRs. Alone among advanced reactor designs, LFTRs have the capacity to reprocess the fuel in the reactor building itself, while the reactor is operating. There’s no opportunity for diversion unless you raid the entire plant, shut down the reactor, and figure out a way to separate and abscond with the weaponizable isotopes. Good luck with that.
3.The claim that radioactive waste from thorium reactors creates waste that would have to be isolated from the environment for only 500 years, whereas irradiated uranium-only fuel remains dangerous for hundreds of thousands of years, is false. Thorium-based reactors create long-lived fission products like technetium-99 (its half-life is more than 200,000 years), and thorium-232 is extremely long lived (its half-life is 14 billion years).
This argument ignores the larger context. The volume of fission products from thorium-based solid fuel reactors is about a tenth of that from conventional reactors. What’s more, in small amounts, many of these fission products have become common in modern life. Technetium-99, for example, is powerful stuff, worthy of respectful treatment; it’s also commonly used, in a slightly altered form, in medical imaging procedures. Millions of patients ingest it every day without significant risk. The amounts of technetium-99 produced in solid-fuel thorium reactors would be negligible; in LFTRs it would be processed off along with other fission products and largely recycled. Some geological storage will be required, but in general waste from LFTRs decays to safe, stable states within a few hundred years—far less than the millennia required for the by-products of uranium reactors. As for Th-232, it’s long lived but safe. The longer-lived a radioactive element is, the lower its radioactivity—with its very long half-life, Th-232 is an exceedingly weak producer of radiation. It is so common that it’s found in small amounts in virtually all rock, soil, and water. You could sleep with it under your pillow and suffer no ill effects.
4.Reprocessing of thorium fuel cycles has not been successful because uranium-232 is created along with uranium-233. U-232, which has a half-life of about 70 years, is extremely radioactive and is therefore quite dangerous in small quantities.
U-232 is indeed extremely radioactive, but its brief half-life means that in less than a century half of it will have decayed to a stable form. Because isotopes decay at a geometric rate (50 percent of half of the original material, or one-quarter of the original, is still radioactive after another 70 years, then one-eighth, one-sixteenth, and so on), the decrease in radioactivity drops off quickly. Many, many hazardous materials are put in storage for centuries. We do not object to them.
To summarize, the most common objections to thorium power from the perspective of radioactive waste and the proliferation of nuclear weapons are inflated for solid fuel reactors, and they simply do not apply to LFTRs. That leaves the traditionalist argument, which essentially echoes Milton Shaw and the WASH-1222 report from 1972: It can’t be done because it has never been done before. When I heard this brand of defeatism, it always came from someone with a vested interest in the current nuclear power establishment. I’ll explore the traditionalist argument in more detail in the final pages of this book. By early 2012, even as the Blue Ribbon Commission presented its blueprint for a nuclear future, the naysaying by a growing chorus of thorium advocacy, as the early believers—Kirk Sorensen, John Kutsch, Robert Hargraves, and others—were joined by a new group of converts, some of whom were businessmen with more concrete plans, and more access to capital, than the original enthusiasts. The thorium revival was entering a new phase.