Scientists launch the world’s largest fusion reactor for the first time
Last week, scientists working on the JT-60SA experimental reactor at the National Institutes of Quantum Science and Technology in Naka City achieved the “first plasma,” according to… Sciences. This effectively means that the machine has been successfully commissioned, but there is still a long way to go before meaningful tests can be performed or any power produced.
However, this is a significant achievement for a reactor intended to pave the way for the larger ITER reactor being built in France, which is expected to be the first of its kind to generate more energy than it uses. Both projects are part of a 2007 agreement between Japan and the European Union to cooperate on fusion research, and lessons learned from operating the JT-60SA will guide ITER’s development.
The reactor follows a well-established design known as a tokamak, which features a donut-shaped chamber surrounded by superconducting coiled magnets. These magnets are used to generate powerful magnetic fields capable of containing an extremely hot cloud of ionized gas known as plasma. In this case, the plasma consists of hydrogen and its isotope deuterium.
When temperatures get high enough, atoms in the plasma fuse together, generating huge amounts of energy in the form of radiation and heat. This is absorbed by the reactor walls and used to convert water into steam that can drive turbines to generate electricity.
The JT-60SA is 15.5 meters high and can carry 135 cubic meters of plasma, making it the largest tokamak built to date, but it is still a long way from serving as a power plant. As with its predecessors, achieving fusion would require much more energy than the reaction generates.
But the new reactor is not supposed to reach the energy break-even point. Its mission is to serve as a test platform for ITER, which is currently under construction at Cadarache in southern France, by helping to verify the stability of the plasma and how it affects energy production. ITER will be about twice as long as the JT-60SA and will be able to carry 830 cubic meters of plasma.
Once fully operational, ITER is expected to generate 500 megawatts of power from its plasma while using only 50 megawatts to heat it. It’s not designed to generate electricity from that energy, but achieving that kind of energy gain would be a critical milestone on the road to commercial power plants.
The JT-60SA reactor is expected to reach full capacity in the next two years, while ITER aims to produce the first plasma by 2025 and be fully operational by 2035. But both projects experienced significant delays and had to regularly update their schedules, which contributed to the merger. The reputation of power as a technology will always be 20 years away.
Meanwhile, a new crop of fusion energy startups have emerged with more aggressive timelines. Companies like Commonwealth Fusion Systems believe they can have a working fusion power plant up and running by the early 2030s, and Helion Energy has signed a power purchase agreement with Microsoft to start providing electricity as early as 2028.
These companies are betting on their ability to move beyond heavier-handed government-run initiatives that have been a slow and steady process for decades. It remains to be seen whether these ambitious goals will succeed, and it is worth noting that the only facility to achieve a net energy gain in a fusion reaction to date is Lawrence Livermore National Laboratory.
But having private and public investment in nuclear fusion energy can only be a good thing. The more people there are working on the problem, the faster we are likely to solve it.
Image source: Engin Akyurt/Pixabay
