Korea's 'artificial sun' setting nuclear fusion records

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Korea's 'artificial sun' setting nuclear fusion records

Published: 24 Feb. 2023, 16:20 Updated: 24 Feb. 2023, 19:06

Korea Superconducting Tokamak Advanced Research (Kstar) located at the Korea Institute of Fusion Energy (KFE) in Daejeon [KFE]

A donut-shaped nuclear fusion reactor, 9 meters (30 feet) wide, 6 meters high and weighing 1,000 tons, welcomes visitors at the Korea Institute of Fusion Energy (KFE) in the central Korean city of Daejeon.

In October, the machine will confine plasma for more than 50 seconds at 100 million degrees Celsius (180 million degrees Fahrenheit) to renew its own record once again.

Dubbed the "artificial sun," the Kstar — the Korea Superconducting Tokamak Advanced Research — was developed by KFE in 1995 to research nuclear fusion power.

The donut-shaped device is a tokamak, a reactor that generates energy by confining plasma with a powerful magnetic field.

In the case of Kstar, that field is generated by a 37.65-million-kilometer-long (23.4 million miles) filament, long enough to make 48 round trips between the Earth and moon.

The nuclear fusion reactor is safely secured in a testing facility built with enough concrete for 1,000 apartment buildings.

Nuclear fusion, or how the sun powers itself, theoretically generates seven times as much energy as fission, but with no pollution or waste.

Fusion energy is an unlimited source of energy that will never deplete, but also the apex of nuclear technology due to the difficulty of maintaining plasma at a super-high temperature.

Kstar was the first tokamak to reach a plasma temperature of 100 million degrees Celsius in 2018.

It also set the world record for maintaining that temperature the longest the following year with 8 seconds, a record it has renewed every year, climbing to 30 seconds in 2021.

The inner view of Kstar [KFE]

“Once we reach 300 seconds, there is no problem — in theory — having the plasma last for 24 hours,” KFE vice president Yoon Si-woo said, referring to the institute’s plan to reach 300 seconds by 2026.

Among the sources that maintain the plasma is tritium.

A hydrogen isotope with two neutrons and one proton in its nucleus, unlike common hydrogen with only one proton, tritium is close to impossible to find in nature.

Most of it is found in nuclear power plants, but only two — in Korea and Canada — can isolate the hydrogen atom for industrial use.

Tritium was long neglected as nuclear waste but is now a high-value material for nuclear fusion research, costing around 35 million won ($27,000) per gram.

“It was the black sheep of the family,” said a source from the science community who requested anonymity. “Now it allows us to lead the International Thermonuclear Experimental Reactor (ITER) project.”

ITER is an international nuclear fusion research and engineering megaproject for creating nuclear fusion energy, with Korea, the United States, Japan, European Union, China, India and Russia as members.

The project aims to test massive nuclear energy production from 2035.

Once commercialized, a single fusion reactor the size of a house will be able to generate more energy than several conventional nuclear power plants.

BY LEE HEE-KWON,SOHN DONG-JOO [sohn.dongjoo@joongang.co.kr]