As energy prices across the United States, with electricity prices jumping 9% year over year, it is becoming clearer by the day that affordable alternatives to fossil fuels are needed not only to environmental reasons, but also to reduce the pressure on our wallets.
Nuclear fusion is an alternative on the horizon that, until recent years, looked more like science fiction than fact. Now, a report from a private nuclear power company in the UK has pushed that reality even closer to realization in a donut-shaped nuclear reactor called a tokamak. Last week, Tokamak Energy announced that its ST-40 spherical tokamak reactor had reached the 100 million degree Celsius threshold for commercially viable nuclear fusion.
“We are proud to have achieved this breakthrough that brings us closer to providing the world with a new source of safe, carbon-free energy,” Chris Kelsall, CEO of Tokamak Energy, said in a statement. “[This] represent[s] the optimal path to obtain clean, low-cost commercial fusion energy”.
Here’s the background — Tokamaks aren’t the only reactors being tested for nuclear fusion – earlier this year Reverse reported on fusion breakthroughs as part of Livermore Labs’ inertial confinement program – but they’re a very popular option with a long history. In a nutshell, tokamaks are generally doughnut-shaped (or torus) reactors that crush and heat hydrogen atoms in a vacuum until they turn into plasma. Given enough heat and pressure, this plasma then undergoes a fusion process similar to that at the center of a star to create a large burst of energy.
The ST-40 is not the first tokamak to achieve this temperature threshold – the Princeton Large Torus tokamak achieved this threshold in 1978. But it is the first to do so with a privately funded spherical tokamak.
Gerald Navratil is the Edison Professor of Applied Physics at Columbia University and has done fusion research at the university for 45 years. Navratil is not affiliated with the Tokamak Energy project but tells Reverse the breakthrough is exciting for the field of nuclear fusion as a whole.
“These are exciting times for fusion energy research,” says Navratil. “For a compact, privately funded fusion experiment costing $70 million to reach this temperature level, that means they have reached one (of several) conditions necessary for the success of the energy of fusion, which is remarkable.”
Why is it important – In nuclear fusion research, Navratil says that private sector-funded projects (like ST-40) and government-funded projects (like ITER in France) work “in great synergy” and even in symbiosis with each other. others. This means that breakthroughs in private companies like Tokamak Energy are good for the advancement of other projects and vice versa.
“We have reached a level of maturity in fusion science achieved through public funding that now enables very important (but more risky) steps in fusion power experiments funded by private investors,” Navratil says. .
“As these private companies progress alongside public research efforts, I expect that many private efforts will fail to fully achieve their goals,” he continues. “The entire field will benefit from the results of these private efforts, and one or more could indeed achieve significant success.”
The success of these efforts could revolutionize access to clean, safe and sustainable energy sources.
What did they do – We don’t know for sure the secret sauce that allowed the ST-40 to achieve this melting milestone, but several unique tokamak components likely played a role in its success:
- Its spherical shape means that the magnets inside the reactor are closer to the plasma flow than in torus-shaped tokamaks. As a result, smaller and cheaper magnets can be used to create even stronger fields.
- The reactor also used high-temperature superconducting magnets that operate between -250 and -200 °C (-418 and -328 °F) and helped keep the reactor cool.
Even though ST-40 was able to reach this crucial fusion threshold, Navratil says there are still many questions to be answered before this type of reaction can truly be used commercially.
“The ST-40 results claim to have reached a sufficient temperature, but for how long was this maintained? At what density? And with what ‘energetic confinement time’?” Navratil says. business merger [will] require advances in physics and technology. Even once the requirements of plasma physics are met, there are a host of technological requirements that must also be met to make fusion a commercially viable source of energy.
This will include the development of a fusion power system, power conversion technology and next-generation radiation-resistant materials, he says.
And after – The list of hurdles that still stand in the way of commercial fusion may seem daunting, but it hasn’t stopped researchers so far in their 70-year journey towards that goal. As for the ST-40, Tokamak Energy is already designing the next generation of the reactor which it hopes will inform the construction of the first fusion power plant in the 2030s.