On Friday, Japan hosted the world’s largest operational experimental nuclear fusion reactor. Although this technology is still in its early stages, some believe it holds the key to meeting humanity’s energy needs in the future.
As opposed to fission, which is still employed in nuclear power plants, fusion involves the fusion of two atomic nuclei rather than the splitting of one.
The JT-60SA reactor’s objective is to explore the viability of fusion as a large-scale, carbon-free, safe source of net energy that produces more energy than it takes to produce.
The six-storey-high machine, in a hangar in Naka north of Tokyo, comprises a donut-shaped “tokamak” vessel set to contain swirling plasma heated up 200 million degrees Celsius (360 million degrees Fahrenheit).
It is an EU-Japan collaborative project that serves as a model for its larger French counterpart, the International Thermonuclear Experimental Reactor (ITER).
In order to replicate the process that occurs within the Sun and release energy in the form of light and heat, the ultimate goal of both efforts is to persuade hydrogen nuclei inside to fuse into one heavier element, helium.
The goal of ITER, which is over budget, behind time, and dealing with serious technical issues, is to produce net energy—the holy grail of nuclear fusion technology.
Sam Davis, deputy project leader for the JT-60SA, said the device will “bring us closer to fusion energy”.
“It’s the result of a collaboration between more than 500 scientists and engineers and more than 70 companies throughout Europe and Japan,” Davis said at Friday’s inauguration.
EU energy commissioner Kadri Simson said the JT-60SA was “the most advanced tokamak in the world”, calling the start of operations “a milestone for fusion history”.
“Fusion has the potential to become a key component for energy mix in the second half of this century,” Simson added.
At the National Ignition Facility at Lawrence Livermore National Laboratory in the United States—home of the biggest laser in the world—the achievement of “net energy gain” was accomplished in December.
The US facility employs an alternative technique to ITER and the JT-60SA called inertial confinement fusion, which involves concurrently directing high-energy lasers into a hydrogen-filled cylinder the size of a thimble.
The outcome was hailed by the US government as a “landmark achievement” in the fight for a clean, limitless energy source and the removal of fossil fuel dependency, which contributes to both global instability and climate change.
Unlike fission, fusion carries no risk of catastrophic nuclear accidents — like that seen in Fukushima in Japan in 2011 — and produces far less radioactive waste than current power plants, its exponents say.
