Atomic boom

Atomic boom

For more technology stories, visit newscientist.com/technology TECHNOLOGY INSIGHT Nuclear energy Atomic boom A flurry of start-up firms aim to turn ...

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For more technology stories, visit newscientist.com/technology

TECHNOLOGY INSIGHT Nuclear energy

Atomic boom A flurry of start-up firms aim to turn nuclear energy into a hot topic SPLITTING the atom has joined the start-up scene. Green energy firms have long been popular ventures for entrepreneurs, but nuclear power has largely been ignored, thanks to the extreme cost, safety issues and the worries about nuclear proliferation that are usually associated with such an undertaking. But a small group of nuclear scientists believe they can change things. By building new types of reactors, some of which reuse spent fuel rods from massive – and often ageing – power plants, they aim to commercialise cheaper, safer

replacements to transform the industry. At the centre of conventional reactors are rods of uranium submerged in water. The rods contain about 5 per cent uranium-235, which readily sheds neutrons. As these neutrons fly into other uranium atoms, they knock loose more neutrons in a chain reaction that heats up the surrounding water. The steam this process creates is used to drive turbines to generate electricity. These reactors make up the vast majority in service globally. The trouble is that, by the time the rods need replacing, only about one-twentieth

company’s chief science officer. WAMS is not the only game in town, though. With investment from Bill Gates, TerraPower of Bellevue, Washington, is designing a “travelling wave” reactor, which uses spent fuel to create a slowly expanding ring of fission in a reactor core that could sustain itself for decades. The journey from the drawing board is long and expensive. Transatomic is currently looking to raise a “couple million dollars” to do materials testing, which will take about two years, says

of the radioactive material they contain has been used up, and so these power plants quickly accumulate highly radioactive waste. Enter the Waste Annihilating Molten Salt (WAMS) reactor, which is being developed by Transatomic Power in Cambridge, Massachusetts. The design calls for uranium and plutonium “If all the nuclear waste in existence was reused, in used fuel rods to be dissolved in it could meet the planet’s a tank of liquid lithium-fluoride salts. power needs for 72 years” Heat from the radioactive elements builds within the salt, which can then CEO Russ Wilcox. Then it would make be circulated out of the reactor’s core a small demonstration plant, and to a heat exchanger, where water is finally a full-scale plant able to produce turned into steam to drive a turbine. 500 megawatts. The whole process The design should mean that could take 15 to 20 years. a disaster like the one in Fukushima, But if entrepreneurs don’t shoot Japan, is out of the question: in the case for radical improvements to nuclear of a power outage, the unchecked power, who will, says Jacob DeWitte, heating of the molten salt would melt CEO of UPower Technologies in a plug below the core, draining the Boston. “Newer companies can help salt into a containment vessel that stimulate innovation in a traditional dissipates the heat. This would allow it to cool and solidify within a few hours, start-up sense,” he says. “Go hard, go fast, and try to make this a reality.” locking in any hazardous materials. Within five years, his firm hopes If all the nuclear waste currently to commercialise what it calls a “nanoin existence was reused in such nuclear battery” that fits in a shipping reactors, they could supply the entire container and generates 1 megawatt planet’s power needs for 72 years, of power. Martin LaMonica ■ carbon-free, claims Leslie Dewan, the

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22 | NewScientist | 12 April 2014

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