> > > > > > September 24, 2013 > Atomic Goal: 800 Years of Power From Waste > By MATTHEW L. WALD > BELLEVUE, Wash. — In a drab one-story building here, set between an indoor > tennis club and a home appliance showroom, dozens of engineers, physicists > and nuclear experts are chasing a radical dream of Bill Gates. > > The quest is for a new kind of nuclear reactor that would be fueled by > today’s nuclear waste, supply all the electricity in the United States for > the next 800 years and, possibly, cut the risk of nuclear weapons > proliferation around the world. > > The people developing the reactor work for a start-up, TerraPower, led by Mr. > Gates and a fellow Microsoft billionaire, Nathan Myhrvold. So far, it has > raised tens of millions of dollars for the project, but building a prototype > reactor could cost $5 billion — a reason Mr. Gates is looking for a home for > the demonstration plant in rich and energy-hungry China. > > (Mr. Gates, of course, has plenty of money of his own. This year Forbes > listed him as the world’s second-richest person, with a net worth of $67 > billion.) > > “The hope is that we’ll find a country, with China being the most likely, > that would be able to build the demo plant,” Mr. Gates said last year in a > conversation with the energy expert Daniel Yergin. “If that happens, then the > economics of this are quite a bit better than the plants we have today.” > > Perhaps one of the most intriguing arguments supporters make about Mr. > Gates’s reactor is that it could eliminate several routes to weapons > proliferation. Iran, for example, says its nuclear program is for peaceful > purposes, but it is enriching far more uranium than it needs for power > generation. The United States has long said that Iran’s enrichment could lead > to a nuclear bomb. > > Today’s nuclear reactors run on concentrations of 3 to 5 percent uranium 235, > an enriched fuel that leaves behind a pure, mostly natural waste, uranium > 238. (A uranium bomb runs on more than 90 percent uranium 235.) In today’s > reactors, some uranium 238 is converted to plutonium that is used as a small, > supplemental fuel, but most of the plutonium is left behind as waste. > > In contrast, the TerraPower reactor makes more plutonium from the uranium 238 > for use as fuel, and so would run almost entirely on uranium 238. It would > need only a small amount of uranium 235, which would function like lighter > fluid getting a charcoal barbecue started. > > The result, TerraPower’s supporters hope, is that countries would not need to > enrich uranium in the quantities they do now, undercutting arguments that > they have to have vast stores on hand for a civilian program. TerraPower’s > concept would also blunt the logic behind a second route to a bomb: > recovering plutonium from spent reactor fuel, which is how most nuclear > weapons are built. Since so much uranium 238 is available, there would be no > reason to use that plutonium, TerraPower says. > > Countries that do not have nuclear weapons will still need lots of > electricity, said John Gilleland, chief executive of TerraPower, and “we > would like to see them build something that allows us to sleep at night.” > > But no one disputes that this is a very long-term bet. Even optimists say it > would take until at least 2030 to commercialize the technology. What the > competition would look like then — wind, solar, natural gas or some other > technology — is not clear. If the idea can be commercialized, it is not even > clear that TerraPower could do it first. > > The engineers working for Mr. Gates acknowledge the enormous challenges but > say they are convinced that he, and they, are chasing the solution not only > to energy and weapons proliferation but also to climate change and poverty. > > “If you could pick just one thing to lower the price of — to reduce poverty — > by far you would pick energy,” Mr. Gates said as he introduced the reactor > idea in a speech in 2010. “Energy and climate are extremely important to > these people, in fact, more important to them than anyone else on the > planet,” he added, referring to killer floods, droughts and crop failures > driven by carbon dioxide given off in energy production. He illustrated his > talk with a photo of schoolchildren doing their homework under street lamps. > > Doug Adkisson, TerraPower’s senior vice president for operations, said Mr. > Gates had “a very humanitarian but very cold assessment” about nuclear power > and what it could do. What drives him to nuclear power, he said, are the > questions “What have you got, and what can you do to raise the living > standard of a whole lot of people?” > > Despite its difficulties, some outside experts applaud Mr. Gates for trying. > > “If you’ve got a huge amount of money, for whatever reasons, you are willing > to make a long-term bet, which is not typical of what venture capitalists > do,” said Burton Richter, a Nobel laureate in physics. “It’s hard to get a > 20-year thing from the standard venture capital world,” he said, adding that > financing projects like TerraPower’s is more typical of governments or > sovereign wealth funds. > > One-hour meetings with Mr. Gates about TerraPower sometimes turn into > five-hour meetings, associates say. > > In Bellevue, TerraPower is a spinoff of Intellectual Ventures, a company > co-founded by Mr. Myhrvold that focuses on inventing new products and > techniques, among them improved seeds for subsistence farmers and methods for > keeping vaccines cold for weeks in places where there is no electricity. But > its critics call it a patent troll because it buys large portfolios of > technology patents and uses them, they say, to sue software designers, > smartphone makers and others. > > TerraPower employees work in a building that also houses Intellectual > Ventures, which includes a chamber for raising mosquitoes, a test kitchen for > developing new ways to prepare and preserve food, and hand-built, > high-precision instruments for measuring tiny details of prototype nuclear > fuel. > > Some of its equipment has more than one use: the nuclear effort shares a > supercomputer, one of the 500 fastest in the world, with the vaccine and > disease vector section, and a tool that cuts steel with a jet of water > propelled to three times the speed of sound is used for various programs. > > One of the biggest challenges TerraPower faces is that neutrons — the > particles released when a uranium atom is split in a reactor — damage a > reactor’s metal parts. In today’s reactors, the problem is manageable because > the fuel stays in place for no more than six years and can stand the > bombardment. But the TerraPower fuel is supposed to stay in place for 30 > years. > > “The biggest problem is swelling,” said Kevan Weaver, a physicist and > TerraPower’s director of technology development. “The neutrons knock an atom > out of the lattice, and leaves a hole, and then the holes coalesce and form > voids, and the part swells.” > > So TerraPower’s engineers are experimenting with different types of metals, > at different temperatures. In December they will put thousands of samples > into a Russian reactor that will irradiate them for six years, with neutrons > of the same energy that TerraPower’s reactor would have. At the end of this > decade, they will see how the metals’ strength was changed, and predict if > the metal will survive for 30 years. > > Another problem is that when uranium is split, some of the fragments are > gases. This is tolerable in current fuels, but no fuel could hold a 30-year > accumulation. > > Simply designing the core of the reactor is an additional problem. TerraPower > engineers call it a “traveling wave reactor,” because the area in which the > uranium 238 has been converted to plutonium and can be fissioned travels > through the core like a wave. > > But every time the designers change the thickness or type of metal they are > using, the flow of neutrons will change, too, and the 30-year life of the > core is so long that the inventory of fission products, some of which absorb > neutrons, will also change, as some unstable materials give off radiation and > transmute themselves into something else. > > To allow the neutrons to travel at a speed that is best for converting waste > uranium into plutonium fuel, the reactor uses sodium, not water, to moderate > the neutrons’ speed and carry off the usable heat. But hot sodium burns on > contact with air. > > TerraPower is not alone in pursuing a reactor that will turn waste uranium > into energy, and if such a concept can be commercialized, Mr. Gates might not > be the first to do it. General Atomics, which has decades of experience in > nuclear power, but is probably best known for producing the Predator drone, > is pursuing what it calls an “energy multiplier” reactor module on the same > general principal. General Atomics, which is based in San Diego, would use > helium, not sodium, however, potentially simplifying some problems. > > “You just set it up, let it burn, and it goes,” said John Parmentola, the > company’s senior vice president. > > Like TerraPower, General Atomics is courting the Chinese. > > > ========================================================================================================= > > > MORE IN ENERGY & ENVIRONMENT (2 OF 21 ARTICLES) > Unilever to Buy Oil Derived From Algae From Solazyme > Read More » > Close > >
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