Today, many countries are participating in fusion research. The leaders are the European Union, the USA, Russia and Japan, and the programs of China, Brazil, Canada and Korea are rapidly expanding. Initially, fusion reactors in the United States and the USSR were associated with the development of nuclear weapons and remained classified until the Atoms for Peace conference held in Geneva in 1958. After the creation of the Soviet tokamak, nuclear fusion research in the 1970s became "big science." But the cost and complexity of the devices increased to the point where international cooperation was the only opportunity to move forward.
Fusion Reactors in the World
Since the 1970s, the beginning of the commercial use of fusion energy has been continuously put off by 40 years. However, much has happened in recent years, so this period can be shortened.
Several tokamaks have been built, including the European JET, the British MAST, and the TFTR experimental fusion reactor in Princeton, USA. The ITER international project is currently under construction in Cadarache, France. It will become the largest tokamak when it starts operating in 2020. In 2030, CFETR will be built in China, which will surpass ITER. Meanwhile, China is conducting research on the experimental superconducting tokamak EAST.
Another type of thermonuclear reactors - stellators - are also popular with researchers. One of the largest, LHD, began work at the Japanese National Institute of Thermonuclear Fusion in 1998. It is used to find the best magnetic plasma confinement configuration. The German Max Planck Institute, from 1988 to 2002, conducted research at the Wendelstein 7-AS reactor in Garching, and now at Wendelstein 7-X, the construction of which lasted more than 19 years. Another TJII stellarator is in operation in Madrid, Spain. In the United States, the Princeton Plasma Physics Laboratory (PPPL), where the first fusion reactor of this type was built in 1951, halted the construction of the NCSX in 2008 due to cost overruns and lack of funding.
In addition, significant successes have been achieved in studies of inertial thermonuclear fusion. The $ 7 billion National Ignition Facility (NIF) at the Livermore National Laboratory (LLNL), funded by the National Nuclear Safety Administration, was completed in March 2009. French Laser Mégajoule (LMJ) began operations in October 2014. Thermonuclear reactors use about 2 million joules of light energy delivered by lasers within a few billionths of a second to a target a few millimeters in size to trigger a nuclear fusion reaction. The main objectives of NIF and LMJ are studies to support national military nuclear programs.
ITER
In 1985, the Soviet Union proposed the construction of the next generation tokamak together with Europe, Japan and the United States. The work was carried out under the auspices of the IAEA. Between 1988 and 1990, the first designs of the ITER International Thermonuclear Experimental Reactor were created, which also means “path” or “journey” in Latin, in order to prove that fusion can generate more energy than absorb. Canada and Kazakhstan also participated through the mediation of Euratom and Russia, respectively.
After 6 years, the ITER Council approved the first comprehensive reactor project based on well-established physics and technology worth $ 6 billion. Then the United States withdrew from the consortium, which forced them to halve costs and change the project. The result was an ITER-FEAT worth $ 3 billion, but allowing for a self-sustaining response and a positive power balance.
In 2003, the United States rejoined the consortium, and China announced its desire to participate in it. As a result, in mid-2005, the partners agreed to build an ITER in Cadarache in southern France. The EU and France contributed half of 12.8 billion euros, while Japan, China, South Korea, the USA and Russia each contributed 10%. Japan provided high-tech components, contained an IFMIF unit worth € 1 billion for material testing, and was eligible for the construction of the next test reactor. The total cost of ITER includes half the cost of 10-year construction and half - for 20 years of operation. India became the seventh member of ITER at the end of 2005.
Experiments should begin in 2018 using hydrogen to avoid magnet activation. The use of plasma DT is not expected before 2026.
The goal of ITER is to generate 500 MW (at least for 400 s) using less than 50 MW of input power without generating electricity.
Demo's two gigawatt demonstration power plant will produce large-scale electricity production on an ongoing basis. The conceptual design of Demo will be completed by 2017, and its construction will begin in 2024. Start-up will take place in 2033.
Jet
In 1978, the EU (Euratom, Sweden and Switzerland) launched a joint European JET project in the UK. JET today is the largest working tokamak in the world. A similar JT-60 reactor operates at the Japanese National Institute of Thermonuclear Fusion, but only JET can use deuterium-tritium fuel.
The reactor was launched in 1983, and became the first experiment, as a result of which in November 1991 controlled fusion was performed with a power of up to 16 MW for one second and 5 MW of stable power in deuterium-tritium plasma. Many experiments have been carried out in order to study various heating schemes and other techniques.
Further enhancements to JET include increasing its power. The MAST compact reactor is being developed with JET and is part of the ITER project.
K-STAR
K-STAR is the Korean superconducting tokamak of the National Institute of Thermonuclear Research (NFRI) in Daejeon, which produced its first plasma in mid-2008. This is an ITER pilot project resulting from international collaboration. A tokamak with a radius of 1.8 m is the first reactor using Nb3Sn superconducting magnets, the same ones that are planned to be used in ITER. During the first stage, which ended by 2012, K-STAR was supposed to prove the viability of basic technologies and achieve plasma pulses lasting up to 20 s. At the second stage (2013–2017), it is modernized to study long pulses up to 300 s in mode H and to switch to a high-performance AT mode. The goal of the third phase (2018–2023) is to achieve high performance and efficiency in the mode of long pulses. At stage 4 (2023–2025), DEMO technologies will be tested. The device is unable to work with tritium and does not use DT fuel.
K-demo
Developed in collaboration with the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) and the NFRI South Korean Institute, K-DEMO should be the next step in creating commercial reactors after ITER, and will be the first power plant to generate power in an electrical network, namely 1 million kW for several weeks. Its diameter will be 6.65 m and it will have a reproduction area module created as part of the DEMO project. The Korean Ministry of Education, Science and Technology plans to invest about a trillion Korean won ($ 941 million) in it.
East
The Chinese experimental advanced superconducting tokamak (EAST) at the Institute of Physics of China in Hefei created a hydrogen plasma with a temperature of 50 million ° C and held it for 102 s.
TFTR
In the American PPPL laboratory, the TFTR experimental fusion reactor ran from 1982 to 1997. In December 1993, TFTR became the first magnetic tokamak to conduct extensive experiments with plasma from deuterium-tritium. The following year, the reactor produced record-breaking 10.7 MW of controllable power at that time, and in 1995 a record of temperature of ionized gas of 510 million ° C was reached. However, the facility did not achieve the breakeven goal of fusion energy, but successfully completed the hardware design goals, making a significant contribution to the development of ITER.
Lhd
LHD at the Japanese National Institute of Thermonuclear Fusion in Toki, Gifu Prefecture, was the largest stellarator in the world. The thermonuclear reactor was launched in 1998, and it demonstrated plasma confinement qualities comparable to other large facilities. An ion temperature of 13.5 keV (about 160 million ° C) and an energy of 1.44 MJ were achieved.
Wendelstein 7-x
After a year of testing, which began at the end of 2015, the temperature of helium for a short time reached 1 million ° C. In 2016, a fusion reactor with a hydrogen plasma, using 2 MW of power, reached a temperature of 80 million ° C in a quarter of a second. W7-X is the largest stellarator in the world and it is planned to operate continuously for 30 minutes. The cost of the reactor amounted to 1 billion €.
Nif
The National Ignition Facility (NIF) at the Livermore National Laboratory (LLNL) was completed in March 2009. Using its 192 laser beams, NIF is able to concentrate 60 times more energy than any previous laser system.
Cold fusion
In March 1989, two researchers, American Stanley Pons and Briton Martin Fleishman, said they launched a simple, room-temperature, cold, desktop fusion reactor. The process consisted in the electrolysis of heavy water using palladium electrodes on which deuterium nuclei were concentrated with high density. Researchers claim that heat was produced that could only be explained in terms of nuclear processes, and there were by-products of fusion, including helium, tritium, and neutrons. However, other experimenters failed to repeat this experiment. Most of the scientific community does not believe that cold fusion reactors are real.
Low energy nuclear reactions
Initiated by claims to “cold fusion,” research continued in the field of low-energy nuclear reactions, with some empirical support, but not a generally accepted scientific explanation. Apparently, weak nuclear interactions are used to create and capture neutrons (rather than a powerful force, as in nuclear fission or fusion). Experiments include the penetration of hydrogen or deuterium through a catalytic bed and reaction with a metal. Researchers report an observed release of energy. The main practical example is the interaction of hydrogen with nickel powder with the release of heat, the amount of which is greater than any chemical reaction can give.