1985 As one of the symbolic actions to end the Cold War, former Soviet leader Gorbachev and US President Ronald Reagan proposed at the Geneva Summit that the United States, the Soviet Union, Europe and Japan jointly launch the International Thermonuclear Experimental Reactor (ITER) program. The goal of ITER program is to build a Tokamak nuclear fusion experimental reactor with self-sustaining combustion (i.e. ignition), so as to deeply explore the physical and engineering problems of future fusion demonstration reactors and commercial fusion reactors.
Initially, the program was only determined to be attended by the United States, Russia, Europe and Japan, independent of the United Nations Atomic Energy Commission (IAEA), and the total part was located in the United States, Japan and Europe. Due to the immature scientific and technological conditions at that time, the preliminary design of ITER proposed by Sifang scientific and technological personnel in 1996 was very unreasonable and required tens of billions of dollars of investment. 1998, for political reasons and domestic disputes, the United States announced its withdrawal from ITER in the name of strengthening basic research. Europe, Japan and Russia continued to cooperate, and on the basis of nuclear fusion research and other new high-tech developments in the 1990s, the design of experimental reactors was greatly revised. In 200 1 year, the joint working group of Europe, Japan and Russia completed the new engineering design (EDA) of ITER device and the development of its main components. The estimated construction cost is USD 5 billion (1998 price), the construction period is 8 to 10 years, and the operation period is 20 years. Since then, the three parties have organized an independent review, and they all think that the design is reasonable and basically acceptable.
In 2002, Europe, Japan and Russia began to negotiate the international agreement of ITER plan and establish corresponding international organizations based on EDA, and welcomed China and the United States to participate in ITER plan. China officially announced its participation in the negotiations on June 5+10/October 38, 2003. Later, at the end of June, 5438+ 10, the United States was specially announced by President George H.W. Bush to rejoin the ITER program, and South Korea was accepted to participate in the ITER program negotiations in 2005. The above-mentioned six parties signed an agreement in June 2005, unanimously agreeing to build ITER in Cadarache, the French nuclear technology research center, thus ending the fierce site selection war. India joined the ITER negotiations in 2006. Finally, on May 25th, 2006, the governments of seven member countries initialled the international agreement for the construction of ITER. At present, international organizations are being formed, and the candidates for director-general and deputy director-general have been determined. Other countries are also considering joining ITER.
Of the total investment of US$ 5 billion (1998) in ITER construction, the European Union contributed 46%, and the United States, Japan, Russia, China, South Korea and India each contributed about 9%. According to the agreement, more than 70% of ITER parts contributed by China are converted by China, 10% is converted by qualified personnel of China Police Department, and less than 20% of foreign exchange needs to be paid to international organizations.
As a fusion energy experimental reactor, ITER will confine the high-temperature plasma composed of hundreds of millions of degrees of deuterium and tritium in a magnetic cage with a volume of 837 cubic meters, generating a fusion power of 500,000 kilowatts for 500 seconds. 500,000 kilowatts of thermal power is equivalent to the level of a small thermal power station. This will be the first time that mankind has obtained a large number of continuous high-temperature plasma of nuclear fusion reaction on the earth, producing controllable fusion energy close to the scale of power station.
The research work carried out on ITER will reveal the characteristics of this high-temperature plasma with deuterium-tritium nuclear fusion reaction, explore its confinement, heating and energy loss mechanism, the behavior of plasma boundary and the best control conditions, thus laying a solid scientific foundation for building commercial nuclear fusion reactors in the future. The research on the changes and possible problems of ITER whole project and its components in the long-term continuous process of 500,000 kW fusion power will not only verify the engineering feasibility of controllable thermonuclear fusion energy, but also provide essential information for how to design and build fusion reactors in the future.
The construction, operation and experimental research of ITER is an inevitable step for human beings to develop fusion energy, which may directly determine the design and construction of a real fusion demonstration power station (demo) and further promote the faster realization of commercial multi-substations.
ITER device is a superconducting tokamak device which can produce large-scale nuclear fusion reaction. The center of the device is a high-temperature deuterium-tritium plasma ring, in which there is a plasma current of 15 mA, and the power of nuclear fusion reaction reaches 500,000 kilowatts, releasing as many as 1020 high-energy neutrons per second. The plasma ring is in the annular sheath of the shielding cladding, which will absorb 500 thousand kilowatts of thermal power and all neutrons produced by nuclear fusion reaction.
Outside the cladding is a huge annular vacuum chamber. There is a deflector connected to the vacuum chamber at the lower side, which can discharge the waste gas after nuclear reaction. The vacuum chamber passes through 16 large superconducting toroidal field coils (i.e. longitudinal field coils).
The annular superconducting magnet will generate a strong annular magnetic field of 5.3 Tesla, which is one of the key components of the device and is worth more than1200 million US dollars.
Passing through the center of the ring is a huge superconducting coil barrel (central solenoid), and six large annular superconducting coils, namely polar field coils, are distributed outside the annular field coils. The central solenoid and the poloidal field coil are used to generate plasma current and control the plasma structure.
The above system is completely enclosed in a large Dewar bottle, which is located on the base to form the experimental reactor body.
Four 10 MW high-current particle accelerators, 10 MW steady millimeter wave system, 20 MW RF wave system and dozens of advanced plasma diagnosis and measurement systems are distributed in vitro.
The whole system also includes: large power supply system, large tritium device, large water supply system (including deionized water), large high vacuum system, large liquid nitrogen and liquid helium cryogenic system, etc.
All possible adjustments and maintenance in ITER are done by remote control robots or robots.
ITER device not only embodies the latest achievements of international fusion energy research, but also integrates some top technologies in various fields in the world, such as large superconducting magnet technology, medium-energy high-current accelerator technology, continuous high-power millimeter wave technology and complex remote control technology.
20 13 (Beijing time) On September 25th, Lawrence Livermore National Laboratory reported that the national ignition facility (NIF), the world's largest laser and known as the "artificial sun", is getting closer and closer to its goal, which indicates that a sustainable nuclear fusion reactor is gradually becoming a reality from a dream. However, there is still a major obstacle to be overcome before the facilities reach a high degree of stability.