‘A gram of fusion fuel could release as much energy as burning 10,000kg of coal’
solution for the climate, to help keep Britain at the forefront of the commercial delivery of fusion.”
The UK and US are friendly rivals, collaborating and competing to develop the technology. But there are other players. China announced five years ago that it would build a nuclear fusion power station and has been training 3,000 engineers for the project. Mowry believes fusion research needs to ditch the tokamak design, which he suggests will never be able to create the stable magnetic fields needed for sustained fusion. He and his colleagues had access to the US Department of Defence’s Exascale computing project that can perform a billion billion calculations operations per second.
The design that emerged looked like a tokamak run over by a tank – a twisted doughnut. But the real power of the computing lay not just in the shape but in working out how to build and maintain the magnetic fields inside the reactor.
“The idea of a stellarator is that if you can figure out exactly how it twists and how to control the magnetic fields it brings a lot of goodness with it,” says Mowry. “Above all it makes the machine inherently stable to produce energy that we can use.”
If he is right, fusion may just one or two decades away, and Britain will share the benefits. Perhaps the most crucial question, however, is how much it will cost. Sir Ian Chapman, the chief executive of the UK Atomic Energy Authority, says one of the biggest costs of nuclear power stations is having to deal with the radioactive materials and wastes.
Fusion, by contrast, generates no long-lived nuclear waste, so any power station based on it could be relatively tiny, perhaps the size of a supermarket.
“Jet, our last machine, would have cost £2bn in today’s money,” says
Sir Ian. “The next generation will have more technology so it will definitely cost more. But it will be a lot less than the tens of billions we are seeing at Hinkley (Britain’s latest nuclear power station). And it will be clean.”