China successfully powered up its ‘artificial sun’ nuclear fusion reactor for the first time, media reported on Friday, marking a great advance in the country’s nuclear power research capabilities.
The HL-2M Experimental Advanced Superconducting Tokamak (EAST) reactor is China’s largest and most advanced nuclear fusion experimental research device, and scientists hope that the device can potentially unlock a powerful clean energy source.
Located in southwestern Sichuan province and completed late last year, the EAST reactor is often called an ‘artificial sun’ on account of the enormous heat and power it produces.
EAST uses a powerful magnetic field to fuse hot plasma and can reach temperatures of over 150 million degrees Celsius, approximately ten times hotter than the core of the Sun. Under such extreme temperatures, atomic nuclei undergo fusion, releasing large amounts of energy in the process.
Nuclear fusion is the energy source that powers our Sun, and is considered the holy grail of clean energy. Unlike nuclear fission used in current nuclear power plants, nuclear fusion does not produce radioactive waste. It also carries less risk of accidents or the theft of atomic material.
The challenge now is to sustain the fusion reaction long enough to produce a net energy output. It costs a huge amount of energy input to bring a tokamak reactor’s entire assembly up to its extreme operating temperature, not to mention the immense magnetic power required to hold the superheated fusing plasma in place.
“The energy confinement time of international tokamak devices is less than one second. The shot discharge duration of the HL-2M is around 10 seconds, with an energy confinement time of a few hundred milliseconds,” said Yang Qingwei, chief engineer of the HL-2M at the Southwestern Institute of Physics under the China National Nuclear Corporation (CNNC).
A secondary challenge is to develop materials that can withstand the extreme forces inside a tokamak fusion reactor. Currently, no man-made material can withstand the cumulative damage from the temperature and subatomic particles released over a period of years or decades.
Scientists plan to use the device in collaboration with the International Thermonuclear Experimental Reactor (ITER) – the world’s largest nuclear fusion research project based in France, which is expected to be completed in 2025. Achieving fusion is both extremely difficult and prohibitively expensive, with the total cost of ITER estimated at US$22.5 billion.