A star is born in Daejeon as Korea leads merger race

The Kstar fusion reactor, or Korea Superconducting Tokamak Advanced Research, built by the Korea Fusion Energy Institute (KFE) is located in Daejeon. [KFE]

DAEJEON – A giant metallic donut could reveal the secrets of eternal energy.

Inside the ship, housed in an unmarked concrete room in Daejeon and connected to a tangle of pipes and cables, hydrogen is heated to 100 million degrees Celsius (180 million degrees Fahrenheit) to achieve fusion.

It’s an artificial sun. And it was tested for a full 30 seconds, a record. No other fusion reactor has ever held the plasma this long.

In theory, such a device will be able to produce stable, inexpensive and almost pollution-free energy. In reality, this will not be possible for decades. If ever.

“When I started researching nuclear fusion 30 years ago, experts were saying that it would take 30 years for mankind to successfully generate electricity from nuclear fusion,” he said. said Yoon Si-woo, deputy general manager of Korea Superconducting Tokamak Advanced Research (Kstar), the experimental fusion reactor.

“We always say it’s going to take us 30 years.”

The idea of ​​fusion dates back a century, and since the 1950s the exploitation of science for peaceful purposes has been attempted by many countries. The break-even point, where more energy is produced than is used to contain the reaction, has never been reached.

Much of the research has focused on the shape of the ship, and the devilishly irregular spheres, stelIarators and tokamak donuts, which have become the norm, have been tried. The hydrogen must be contained by magnets when the atoms fuse together, and the configuration of the container is critical.

The Kstar's tokamak is the doughnut-shaped containment vessel that holds fuel in a magnetic field while fusion takes place.  Inside the tokamak, the hydrogen isotopes are heated to reach the plasma state, where they fuse with each other under the immense heat and create energy in the process. [KFE]

The Kstar’s tokamak is the doughnut-shaped containment vessel that holds fuel in a magnetic field while fusion takes place. Inside the tokamak, the hydrogen isotopes are heated to reach the plasma state, where they fuse with each other under the immense heat and create energy in the process. [KFE]

The Korean Kstar reactor, in service since 2007, is a separate tokamak. Built by the Korean Institute of Fusion Energy (KFE), it uses Nb3Sn, an intermetallic compound composed of niobium and tin and which is a superconductor.

The Kstar reactor is the first fusion reactor to be built with superconductors, giving Korea a competitive advantage over other countries. No other project has been able to contain the super hot plasma for longer than 15 seconds.

Other tokamaks have used copper, which is also a good conductor but not as energy efficient as niobium-tin.

“The ingredient for the rapid success of the Kstar reactor was in the use of Nb3Sn superconductors,” Yoon said.

Korea has been working on fusion since 1995.

In July 2008, the Kstar reactor succeeded in artificially generating plasma. In 2018, plasma reached 100 million degrees Celsius for the first time. Last year, with superconductors, the Kstar reactor held the plasma at over 100 million degrees Celsius for 30 seconds.

The project is targeting 50 seconds this year and 300 seconds by 2026, which Yoon says is “the milestone of 24-hour operation” needed for power generation.

The goal is to contain the material stably and around the clock by 2050.

dream energy

An image in Kstar's tokamak shows the state of the plasma at over 100 million degrees Celsius. [KFE]

An image in Kstar’s tokamak shows the state of the plasma at over 100 million degrees Celsius. [KFE]

Fusion, which powers the stars, is considered the ideal source of energy. Fuel is plentiful – mostly seawater. The process generates negligible pollution and far less radioactive waste than fission, and fusion reactors would be far less dangerous than existing nuclear reactors. Collapses are not possible; if the plasma escapes, the fusion stops.

With just a bathtub of seawater and a lithium battery big enough to run a laptop computer, a working reactor would be able to generate the same amount of energy as burning 40 tons of coal.

The merger has attracted considerable attention in recent years. The Fukushima disaster and efforts to reduce carbon emissions have caused many countries and companies to rush to find clean energy sources, and fusion is coming back into vogue due to its ability to meet demand without the hidden costs and dangers of other alternatives.

Given the new priorities, the funding needed to make fusion a reality could be increased, and working reactors are now more possible than ever.

“Climate change is a big issue, and there’s a lot of interest in the fusion program, with more to come in the years to come,” Yoon said. “The situation has changed, and we are bringing 30 years closer to reality.”

In addition to superconductors, the Korean project uses other technologies that could help bring the dream of fusion energy closer to realization.

It develops a lithium breeding blanket, a lithium “blanket” filled with deuterium – hydrogen with one neutron – which can be transformed into tritium – hydrogen with two neutrons – when it encounters the neutrons which are emitted as a byproduct of nuclear fusion.

Deuterium and tritium fuse more easily than neutron-free hydrogen, and tritium can generate 1,000 times more energy than deuterium. While deuterium can be found in seawater, tritium does not exist in nature.

If the lithium breeding blanket is developed, then a fusion reactor can have a self-contained tritium supply that can run it on just deuterium.

Further upgrades and innovations are planned to help Kstar achieve its goals.

Yoon Si-woo, deputy general manager of the Kstar Research Center of the Korea Institute of Fusion Energy (KFE), explains the design details of Kstar during the press tour last Monday.  Yoon stands next to the equipment that will be used during the renovation of the Kstar which begins in March. [YOON SO-YEON]

Yoon Si-woo, deputy general manager of the Kstar Research Center of the Korea Institute of Fusion Energy (KFE), explains the design details of Kstar during the press tour last Monday. Yoon stands next to the equipment that will be used during the renovation of the Kstar which begins in March. [YOON SO-YEON]

“We will start a renovation of the Kstar reactor in March to upgrade the tokamak with more heat-resistant metal, from carbon-based material to tungsten,” Yoon said. “There are things we have to prove, but we will also solve them along the way to reach the 300 second target in 2026.”

Kstar received 43.2 billion won ($36.3 million) from the government in 2021 and will receive 42.5 billion won this year. A total of 418.2 billion was used to build the reactor.

Overall, from Kurchatov, Kazakhstan to Princeton, New Jersey, more than 20 tokamaks and 10 stellarators are operational, while a dozen of the former and half a dozen of the latter have been abandoned.

International cooperation

The International Thermonuclear Experimental Reactor (ITER), a massive fusion reactor under construction in Saint-Paul-les-Durance, is under construction in August 2021. France and 35 countries, including Korea, are participating in the project. [ITER ORGANIZATION]

The International Thermonuclear Experimental Reactor (ITER), a massive fusion reactor under construction in Saint-Paul-les-Durance, is under construction in August 2021. France and 35 countries, including Korea, are participating in the project. [ITER ORGANIZATION]

Due to the costs and risks of fusion development, cooperation is seen as a way to bridge the last and most difficult mile of research, and a massive multinational project is already underway.

The International Thermonuclear Experimental Reactor (ITER) is a massive fusion reactor under construction in Saint-Paul-lès-Durance. France and 35 nations, including Korea, are participating in the project.

The tokamak will have a radius of 6.2 meters, making it the largest nuclear fusion reactor in the world when completed in 2025.

If all goes as planned, by 2035 it will reach “burning plasma”, where it will create more energy than it uses, and participants will take the technology back to their home countries for the use in their own fusion developments.

ITER will use the same niobium-tin superconductors used in Kstar.

Korean companies that participated in the construction of Kstar are also participating in ITER, including Hyundai Heavy Industries, SFA Engineering, Hyundai Mobis and SeAH Changwon Integrated Special Steel.

As of December last year, Korean companies won 161 contracts related to the ITER project, worth 686.8 billion won.

“Fusion is not just a dream, it is becoming a real source of energy,” said Yoo suk-jae, president of KFE.

“If this becomes a reality, then the source of funding could also diversify. Big companies like Amazon and people like Bill Gates might even be interested. I have very optimistic views, if we can control the plasma.

BY YOON SO-YEON [[email protected]]

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