Nuclear Fusion Reactor Shows Stronger Power Burst
By Kim Tong-hyung
Staff Reporter
Scientists at the National Fusion Research Institute said Wednesday that their experimental fusion reactor set a new high by creating plasma that lasted for 3.6 seconds and generated an electric current of 320 kilo amperes (kA.).
This is nearly three times stronger than an electric burst, and 10 times longer in plasma maintenance, than what KSTAR, an abbreviation for Korea Superconducting Tokamak Advanced Reactor, managed when it generated its first plasma in June last year, the researchers said.
In the first experiments, plasma lasted for 249 milliseconds at above 100 kA, with the max current reaching 133 kA. In the recent testing, the goal was to have the plasma last for 2 seconds and achieve a max 300 kA in electrical current.
KSTAR was the second fusion reactor in the world to generate plasma using superconducting material, following China's EAST reactor which achieved the feat in 2006.
Being one of the world's few fusion reactors using niobium-tin (Nb3Sn) a superconducting material, identical to the design of the International Thermonuclear Experimental Reactor (ITER), local researchers hope KSTAR will allow them to make a meaningful contribution to the international efforts for developing fusion energy.
"The better-than-expected results prove that KSTAR is a reactor built with superior technology and is ready to support a wealth of international research efforts on nuclear fusion," Kwon Myeon, an official at the Daejeon-based National Fusion Research Institute, said.
Scientists from the United States' General Atomics (GA), the Princeton Plasma Physics Laboratory and also representatives from the ITER participated in the recent experiment with KSTAR, Kwon said.
Plasma, generated from the ionizing of hydrogen gas, is a state in which the electrons and the nuclei are separated, and is considered a crucial step before nuclei can collide and fuse.
Fusion reactors generate power by the heating of hydrogen plasma, which causes hydrogen isotopes to fuse and release energy. The duration of the plasma is critical for this process and the reactors are designed with powerful magnetic chambers using superconducting magnets to contain it.
Nuclear fusion is regarded as one of future energy solutions that are limitless in sourcing, a key alternative to the limited and depleted sources of fossil fuels. The viability of the technology is still debated.
To put it simply, nuclear fusion is the process that makes the sun shine, with the nuclei of small atoms, such as hydrogen, squeezed together and heated to an extreme degree such that they fuse to form larger nuclei and release a burst of energy.
Scientists have long been researching ways to create and control the nuclear fusion process for constructive use.
Conventional nuclear power plants depend on materials such as uranium or plutonium to create the fission to generate energy, but the radioactivity of the resulting fragments is considered a crucial drawback. In a nuclear fusion reaction, however, problems about waste disposal are greatly minimized.
Korea is one of the partners in the ITER project that aims to introduce a full-scale demonstration fusion power plant in the mid 2030s and a commercial version capable of making at least 1,000 megawatts of electricity in the 2040s.
The U.S., European Union member states, Japan, Russia, China and India are the other countries involved in the ITER project.
Construction of KSTAR began in 1995 and was completed in late 2007, with the Korean government spending more than 309 billion won (about $266 million) on the project.