International experimental thermonuclear reactor. Road to the Sun - worldwide construction of a fusion reactor in France
How did it all start? The “energy challenge” arose as a result of a combination of the following three factors:
1. Humanity now consumes a huge amount of energy.
Currently, the world's energy consumption is about 15.7 terawatts (TW). Dividing this value by the world population, we get approximately 2400 watts per person, which can be easily estimated and visualized. The energy consumed by every inhabitant of the Earth (including children) corresponds to the round-the-clock operation of 24 hundred-watt electric lamps. However, the consumption of this energy across the planet is very uneven, as it is very large in several countries and negligible in others. Consumption (in terms of one person) is equal to 10.3 kW in the USA (one of the record values), 6.3 kW in the Russian Federation, 5.1 kW in the UK, etc., but, on the other hand, it is equal only 0.21 kW in Bangladesh (only 2% of US energy consumption!).
2. World energy consumption is increasing dramatically.
According to the International Energy Agency (2006), global energy consumption is expected to increase by 50% by 2030. Developed countries could, of course, do just fine without additional energy, but this growth is necessary to lift the people of developing countries, where 1.5 billion people experience poverty, out of poverty. acute shortage electrical energy.
3. Currently, 80% of the world's energy comes from burning fossil fuels. natural fuels (oil, coal and gas), the use of which:
a) potentially poses a risk of catastrophic environmental changes;
b) must inevitably end someday.
From what has been said, it is clear that now we must prepare for the end of the era of using fossil fuels
Currently, nuclear power plants produce energy released during fission reactions on a large scale. atomic nuclei. The creation and development of such stations should be encouraged in every possible way, but it must be taken into account that the reserves of one of the most important materials for their operation (cheap uranium) can also be completely used up within the next 50 years. The possibilities of nuclear fission-based energy can (and should) be significantly expanded through the use of more efficient energy cycles, allowing the amount of energy produced to almost double. To develop energy in this direction, it is necessary to create thorium reactors (the so-called thorium breeder reactors or breeder reactors), in which the reaction produces more thorium than the original uranium, as a result of which total quantity the energy obtained for a given amount of substance increases 40 times. It also seems promising to create plutonium breeders using fast neutrons, which are much more efficient than uranium reactors and can produce 60 times more energy. It may be that to develop these areas it will be necessary to develop new, non-standard methods for obtaining uranium (for example, from sea water, which seems to be the most accessible).
Fusion power plants
The figure shows a schematic diagram (not to scale) of the device and operating principle of a thermonuclear power plant. In the central part there is a toroidal (donut-shaped) chamber with a volume of ~2000 m3, filled with tritium-deuterium (T–D) plasma heated to a temperature above 100 M°C. The neutrons produced during the fusion reaction (1) leave the “magnetic bottle” and enter the shell shown in the figure with a thickness of about 1 m.
Inside the shell, neutrons collide with lithium atoms, resulting in a reaction that produces tritium:
neutron + lithium → helium + tritium
In addition, competing reactions occur in the system (without the formation of tritium), as well as many reactions with the release of additional neutrons, which then also lead to the formation of tritium (in this case, the release of additional neutrons can be significantly enhanced, for example, by introducing beryllium atoms into the shell and lead). The general conclusion is that this facility could (at least theoretically) undergo a nuclear fusion reaction that would produce tritium. In this case, the amount of tritium produced should not only meet the needs of the installation itself, but also be even somewhat larger, which will make it possible to supply new installations with tritium. It is this operating concept that must be tested and implemented in the ITER reactor described below.
In addition, neutrons must heat the shell in so-called pilot installations (in which relatively “ordinary” construction materials) to approximately 400°C. In the future, it is planned to create improved installations with a shell heating temperature above 1000°C, which can be achieved through the use of the latest high-strength materials (such as silicon carbide composites). The heat generated in the shell, as in conventional stations, is taken by the primary cooling circuit with a coolant (containing, for example, water or helium) and transferred to the secondary circuit, where water steam is produced and supplied to the turbines.
1985 - The Soviet Union proposed the next generation Tokamak installation, using the experience of four leading countries in creating thermal nuclear reactors. The United States of America, together with Japan and the European Community, put forward a proposal for the implementation of the project.
Currently, in France, construction is underway on the international experimental thermonuclear reactor ITER (International Tokamak Experimental Reactor), described below, which will be the first tokamak capable of “igniting” plasma.
In the most advanced existing tokamak-type installations, temperatures of about 150 M°C have long been achieved, close to the values required for the operation of a thermonuclear station, however ITER reactor should be the first large-scale power plant designed for long-term operation. In the future, it will be necessary to significantly improve its operating parameters, which will require, first of all, increasing the pressure in the plasma, since the rate of nuclear fusion at a given temperature is proportional to the square of the pressure. Main scientific problem this is due to the fact that when the pressure in the plasma increases, very complex and dangerous instabilities arise, that is, unstable operating modes.
Why do we need this?
The main advantage of nuclear fusion is that it requires very little fuel as fuel. large number very common substances in nature. The nuclear fusion reaction in the described installations can lead to the release of a huge amount of energy, ten million times higher than the standard heat release during conventional chemical reactions(like burning fossil fuels). For comparison, we point out that the amount of coal required to power a thermal power plant with a capacity of 1 gigawatt (GW) is 10,000 tons per day (ten railway cars), and a fusion plant of the same power will consume only about 1 kilogram of the D+T mixture per day .
Deuterium is a stable isotope of hydrogen; In about one out of every 3,350 molecules of ordinary water, one of the hydrogen atoms is replaced by deuterium (a legacy from the Big Bang). This fact makes it easy to organize a fairly cheap production of the required amount of deuterium from water. It is more difficult to obtain tritium, which is unstable (half-life is about 12 years, as a result of which its content in nature is negligible), however, as shown above, tritium will appear directly inside the thermonuclear installation during operation, due to the reaction of neutrons with lithium.
Thus, the initial fuel for a fusion reactor is lithium and water. Lithium is a common metal widely used in household appliances(in batteries for mobile phones, etc.). The installation described above, even taking into account non-ideal efficiency, will be able to produce 200,000 kWh of electrical energy, which is equivalent to the energy contained in 70 tons of coal. The amount of lithium required for this is contained in one computer battery, and the amount of deuterium is in 45 liters of water. The above value corresponds to the current electricity consumption (calculated per person) in the EU countries over 30 years. The very fact that such an insignificant amount of lithium can ensure the generation of such an amount of electricity (without CO2 emissions and without the slightest air pollution) is a fairly serious argument for the fastest and most vigorous development of thermonuclear energy (despite all the difficulties and problems) and even without one hundred percent confidence in the success of such research.
Deuterium should last for millions of years, and reserves of easily mined lithium are sufficient to supply needs for hundreds of years. Even if lithium reserves in rocks run out, we can extract it from water, where it is found in sufficient quantities. high concentration(100 times higher than the concentration of uranium) so that its extraction is economically feasible.
An experimental thermonuclear reactor (International thermonuclear experimental reactor) is being built near the city of Cadarache in France. The main goal of the ITER project is to implement a controlled thermonuclear fusion reaction on an industrial scale.
Per unit weight of thermonuclear fuel, about 10 million times more energy is obtained than when burning the same amount of organic fuel, and about a hundred times more than when splitting uranium nuclei in the reactors of currently operating nuclear power plants. If the calculations of scientists and designers come true, this will give humanity an inexhaustible source of energy.
Therefore, a number of countries (Russia, India, China, Korea, Kazakhstan, USA, Canada, Japan, European Union countries) joined forces in creating the International Thermonuclear Research Reactor - a prototype of new power plants.
ITER is a facility that creates conditions for the synthesis of hydrogen and tritium atoms (an isotope of hydrogen), resulting in the formation of a new atom - a helium atom. This process is accompanied by a huge burst of energy: the temperature of the plasma in which the thermonuclear reaction occurs is about 150 million degrees Celsius (for comparison, the temperature of the Sun’s core is 40 million degrees). In this case, the isotopes burn out, leaving virtually no radioactive waste.
The scheme of participation in the international project provides for the supply of reactor components and financing of its construction. In exchange for this, each of the participating countries receives full access to all technologies for creating a thermonuclear reactor and to the results of all experimental work on this reactor, which will serve as the basis for the design of serial power thermonuclear reactors.
The reactor, based on the principle of thermonuclear fusion, has no radioactive radiation and is completely safe for the environment. It can be located almost anywhere in the world, and its fuel is plain water. Construction of ITER is expected to last about ten years, after which the reactor is expected to be in use for 20 years.
Russia's interests in the Council of the International Organization for the Construction of the ITER Thermonuclear Reactor in the coming years will be represented by Corresponding Member of the Russian Academy of Sciences Mikhail Kovalchuk - Director of the Kurchatov Institute, Institute of Crystallography of the Russian Academy of Sciences and Scientific Secretary of the Presidential Council on Science, Technology and Education. Kovalchuk will temporarily replace Academician Evgeniy Velikhov in this post, who was elected chairman for the next two years international council ITER and does not have the right to combine this position with the duties of an official representative of a participating country.
The total cost of construction is estimated at 5 billion euros, and the same amount will be required for trial operation of the reactor. The shares of India, China, Korea, Russia, the USA and Japan each account for approximately 10 percent of the total value, 45 percent comes from the countries of the European Union. However, the European states have not yet agreed on how exactly the costs will be distributed between them. Because of this, the start of construction was postponed to April 2010. Despite the latest delay, scientists and officials involved in ITER say they will be able to complete the project by 2018.
The estimated thermonuclear power of ITER is 500 megawatts. Individual magnet parts reach a weight of 200 to 450 tons. To cool ITER, 33 thousand cubic meters of water per day will be required.
In 1998, the United States stopped funding its participation in the project. After the Republicans came to power and rolling blackouts began in California, the Bush administration announced increased investment in energy. The United States did not intend to participate in the international project and was engaged in its own thermonuclear project. In early 2002, President Bush's technology adviser John Marburger III said that the United States had changed its mind and intended to return to the project.
The project in terms of the number of participants is comparable to another major international scientific project - the International space station. The cost of ITER, which previously reached 8 billion dollars, then amounted to less than 4 billion. As a result of the withdrawal of the United States from participation, it was decided to reduce the reactor power from 1.5 GW to 500 MW. Accordingly, the price of the project has also decreased.
In June 2002, the symposium “ITER Days in Moscow” was held in the Russian capital. It discussed the theoretical, practical and organizational problems of reviving the project, the success of which can change the fate of humanity and give it new look energy, comparable in efficiency and economy only to the energy of the Sun.
In July 2010, representatives of the countries participating in the ITER international thermonuclear reactor project approved its budget and construction schedule at an extraordinary meeting held in Cadarache, France. The meeting report is available here.
At the last extraordinary meeting, project participants approved the start date for the first experiments with plasma - 2019. Full experiments are planned for March 2027, although the project management asked technical specialists to try to optimize the process and begin experiments in 2026. The meeting participants also decided on the costs of constructing the reactor, but the amounts planned to be spent on creating the installation were not disclosed. According to information received by the editor of the ScienceNOW portal from an unnamed source, by the time experiments begin, the cost of the ITER project could reach 16 billion euros.
The meeting held in Cadarache also became the first official working day for the new project director, Japanese physicist Osamu Motojima. Before him, the project had been led since 2005 by the Japanese Kaname Ikeda, who wished to leave his post immediately after the budget and construction deadlines were approved.
The ITER fusion reactor is a joint project of the European Union, Switzerland, Japan, USA, Russia, South Korea, China and India. The idea of creating ITER has been under consideration since the 80s of the last century, however, due to financial and technical difficulties, the cost of the project is constantly growing, and the construction start date is constantly being postponed. In 2009, experts expected that work on creating the reactor would begin in 2010. Later, this date was moved, and first 2018 and then 2019 were named as the launch time of the reactor.
Thermonuclear fusion reactions are reactions of fusion of nuclei of light isotopes to form a heavier nucleus, which are accompanied by a huge release of energy. In theory, fusion reactors can produce a lot of energy at low cost, but at the moment scientists spend much more energy and money to start and maintain the fusion reaction.
Thermonuclear fusion is a cheap and environmentally friendly way to produce energy. Uncontrolled thermonuclear fusion has been occurring on the Sun for billions of years - helium is formed from the heavy hydrogen isotope deuterium. This releases a colossal amount of energy. However, people on Earth have not yet learned to control such reactions.
The ITER reactor will use hydrogen isotopes as fuel. During a thermonuclear reaction, energy is released when light atoms combine into heavier ones. To achieve this, the gas must be heated to a temperature of over 100 million degrees - much higher than the temperature at the center of the Sun. Gas at this temperature turns into plasma. At the same time, atoms of hydrogen isotopes merge, turning into helium atoms with the release of a large number of neutrons. A power plant operating on this principle will use the energy of neutrons slowed down by a layer of dense material (lithium).
Why did the creation of thermonuclear installations take so long?
Why have such important and valuable installations, the benefits of which have been discussed for almost half a century, not yet been created? There are three main reasons (discussed below), the first of which can be called external or social, and the other two - internal, that is, determined by the laws and conditions of the development of thermonuclear energy itself.
1. For a long time, it was believed that the problem of the practical use of thermonuclear fusion energy did not require urgent decisions and actions, since back in the 80s of the last century, fossil fuel sources seemed inexhaustible, and environmental problems and climate change did not concern the public. In 1976, the Advisory Committee on thermonuclear energy in the US Department of Energy tried to estimate the time frame for R&D and the creation of a demonstration thermonuclear power plant with different research funding options. At the same time, it was discovered that the volume of annual funding for research in this direction is completely insufficient, and if the existing level of appropriations is maintained, the creation of thermonuclear installations will never be successful, since the allocated funds do not correspond even to the minimum, critical level.
2. A more serious obstacle to the development of research in this area is that a thermonuclear installation of the type under discussion cannot be created and demonstrated on a small scale. From the explanations presented below, it will become clear that thermonuclear fusion requires not only magnetic confinement of the plasma, but also sufficient heating of it. The ratio of expended and received energy increases at least in proportion to the square of the linear dimensions of the installation, as a result of which the scientific and technical capabilities and advantages of thermonuclear installations can be tested and demonstrated only at fairly large stations, such as the mentioned ITER reactor. Society was simply not ready to finance such large projects until there was sufficient confidence in success.
3. The development of thermonuclear energy was very complex, however (despite insufficient funding and difficulties in choosing centers for creating the JET and ITER installations) recent years There is clear progress, although a functioning station has not yet been created.
The modern world is facing a very serious energy challenge, which can more accurately be called an “uncertain energy crisis.” The problem is related to the fact that reserves of fossil fuels may run out in the second half of this century. Moreover, burning fossil fuels may result in the need to somehow sequester and “store” the carbon dioxide released into the atmosphere (the CCS program mentioned above) to prevent major changes in the planet’s climate.
Currently, almost all the energy consumed by humanity is created by burning fossil fuels, and the solution to the problem may be associated with the use of solar energy or nuclear energy (the creation of fast breeder reactors, etc.). Global problem, driven by the growing population of developing countries and their need to improve living standards and increase the amount of energy produced, cannot be solved only on the basis of the approaches considered, although, of course, any development attempts should be encouraged alternative methods energy production.
Strictly speaking, we have a small choice of behavioral strategies and the development of thermonuclear energy is extremely important, even despite the lack of a guarantee of success. The Financial Times newspaper (dated January 25, 2004) wrote about this:
“Even if the costs of the ITER project significantly exceed the original estimate, they are unlikely to reach the level of $1 billion per year. This level of expenditure should be considered a very modest price to pay for a very reasonable opportunity to create a new source of energy for all of humanity, especially given the fact that already in this century we will inevitably have to give up the habit of wasteful and reckless burning of fossil fuels.”
Let's hope that there will be no major and unexpected surprises on the path to the development of thermonuclear energy. In this case, in about 30 years we will be able to supply electric current from it to energy networks for the first time, and in just over 10 years the first commercial thermonuclear power plant will begin to operate. It is possible that in the second half of this century, nuclear fusion energy will begin to replace fossil fuels and gradually begin to play an increasingly important role. important role in providing energy to humanity on a global scale.
There is no absolute guarantee that the task of creating thermonuclear energy (as an effective and large-scale source of energy for all humanity) will be completed successfully, but the likelihood of success in this direction is quite high. Considering the enormous potential of thermonuclear stations, all costs for projects for their rapid (and even accelerated) development can be considered justified, especially since these investments look very modest against the backdrop of the monstrous global energy market ($4 trillion per year8). Meeting humanity's energy needs is a very serious problem. As fossil fuels become less and less available (and their use becomes undesirable), the situation is changing, and we simply cannot afford not to develop fusion energy.
To the question “When will thermonuclear energy appear?” Lev Artsimovich (a recognized pioneer and leader of research in this field) once responded that “it will be created when it becomes truly necessary for humanity”
ITER will be the first fusion reactor to produce more energy than it consumes. Scientists measure this characteristic using a simple coefficient they call "Q." If ITER achieves all its scientific goals, it will produce 10 times more energy than it consumes. The last device built, the Joint European Torus in England, is a smaller prototype fusion reactor that, in its final stages of scientific research, achieved a Q value of almost 1. This means that it produced exactly the same amount of energy as it consumed. ITER will go beyond this by demonstrating energy creation from fusion and achieving a Q value of 10. The idea is to generate 500 MW from an energy consumption of approximately 50 MW. Thus, one of the scientific goals of ITER is to prove that a Q value of 10 can be achieved.
Another scientific goal is that ITER will have a very long "burn" time - a pulse of extended duration up to one hour. ITER is a research experimental reactor that cannot produce energy continuously. When ITER starts operating, it will be on for one hour, after which it will need to be turned off. This is important because until now the standard devices we have created have been capable of having a burning time of several seconds or even tenths of a second - this is the maximum. The "Joint European Torus" reached its Q value of 1 with a burn time of approximately two seconds with a pulse length of 20 seconds. But a process that lasts a few seconds is not truly permanent. By analogy with starting a car engine: briefly turning on the engine and then turning it off is not yet real operation of the car. Only when you drive your car for half an hour will it reach a constant operating mode and demonstrate that such a car can actually be driven.
That is, from a technical and scientific point of view, ITER will provide a Q value of 10 and an increased burn time.
The thermonuclear fusion program is truly international and broad in nature. People are already counting on the success of ITER and are thinking about the next step - creating a prototype of an industrial thermonuclear reactor called DEMO. To build it, ITER needs to work. We must achieve our scientific goals because this will mean that the ideas we put forward are entirely feasible. However, I agree that you should always think about what's next. In addition, as ITER operates for 25-30 years, our knowledge will gradually deepen and expand, and we will be able to more accurately outline our next step.
Indeed, there is no debate about whether ITER should be a tokamak. Some scientists pose the question quite differently: should ITER exist? Specialists in different countries ah, developing their own, not so large-scale thermonuclear projects, claim that such a large reactor is not needed at all.
However, their opinion should hardly be considered authoritative. Physicists who have been working with toroidal traps for several decades were involved in the creation of ITER. The design of the experimental thermonuclear reactor in Karadash was based on all the knowledge gained during experiments on dozens of predecessor tokamaks. And these results indicate that the reactor must be a tokamak, and a large one at that.
JET At the moment, the most successful tokamak can be considered JET, built by the EU in the British town of Abingdon. This is the largest tokamak-type reactor created to date, the large radius of the plasma torus is 2.96 meters. The power of the thermonuclear reaction has already reached more than 20 megawatts with a retention time of up to 10 seconds. The reactor returns about 40% of the energy put into the plasma.
It is the physics of plasma that determines the energy balance,” Igor Semenov told Infox.ru. What is energy balance, MIPT associate professor described at simple example: “We all saw the fire burning. In fact, it is not wood that burns there, but gas. The energy chain there is like this: the gas burns, the wood heats, the wood evaporates, the gas burns again. Therefore, if we throw water on a fire, we will abruptly take energy from the system for the phase transition of liquid water into a vapor state. The balance will become negative and the fire will go out. There is another way - we can simply take the firebrands and spread them in space. The fire will also go out. It’s the same in the thermonuclear reactor we are building. The dimensions are chosen to create an appropriate positive energy balance for this reactor. Sufficient to build a real nuclear power plant in the future, solving at this experimental stage all the problems that currently remain unresolved.”
The dimensions of the reactor were changed once. This happened at the turn of the 20th-21st century, when the United States withdrew from the project, and the remaining members realized that the ITER budget (by that time it was estimated at 10 billion US dollars) was too large. Physicists and engineers were required to reduce the cost of installation. And this could only be done due to size. The “redesign” of ITER was led by the French physicist Robert Aymar, who previously worked on the French Tore Supra tokamak in Karadash. The outer radius of the plasma torus has been reduced from 8.2 to 6.3 meters. However, the risks associated with the reduction in size were partly compensated for by several additional superconducting magnets, which made it possible to implement the plasma confinement mode, which was open and studied at that time.
Fusion power plant.
Currently, scientists are working on the creation of a thermonuclear power plant, the advantage of which is to provide humanity with electricity for an unlimited time. A thermonuclear power plant operates on the basis of thermonuclear fusion - the reaction of synthesis of heavy hydrogen isotopes with the formation of helium and the release of energy. The thermonuclear fusion reaction does not produce gaseous or liquid radioactive waste and does not produce plutonium, which is used for production nuclear weapons. If we also take into account that the fuel for thermonuclear stations will be the heavy hydrogen isotope deuterium, which is obtained from simple water - half a liter of water contains fusion energy equivalent to that obtained by burning a barrel of gasoline - then the advantages of power plants based on thermonuclear reactions become obvious .
During a thermonuclear reaction, energy is released when light atoms combine and transform into heavier ones. To achieve this, it is necessary to heat the gas to a temperature of over 100 million degrees - much higher than the temperature at the center of the Sun.
Gas at this temperature turns into plasma. At the same time, atoms of hydrogen isotopes merge, turning into helium atoms and neutrons and releasing a large amount of energy. A commercial power plant operating on this principle would use the energy of neutrons moderated by a layer of dense material (lithium).
Compared to a nuclear power plant, a fusion reactor will leave behind much less radioactive waste.
International thermonuclear reactor ITER
Participants in the international consortium to create the world's first thermonuclear reactor, ITER, signed an agreement in Brussels that launches the practical implementation of the project.
Representatives of the European Union, the United States, Japan, China, South Korea and Russia intend to begin construction of the experimental reactor in 2007 and complete it within eight years. If everything goes according to plan, then by 2040 a demonstration power plant operating on the new principle could be built.
I would like to believe that the era of environmentally hazardous hydroelectric and nuclear power plants will soon end, and the time will come for a new power plant - a thermonuclear one, the project of which is already being implemented. But, despite the fact that the ITER (International Thermonuclear Reactor) project is almost ready; despite the fact that already in the first operating experimental thermonuclear reactors a power exceeding 10 MW was obtained - the level of the first nuclear power plants, the first thermonuclear power plant will not work earlier than in twenty years, because its cost is very high. The cost of the work is estimated at 10 billion euros - this is the most expensive international power plant project. Half of the costs of constructing the reactor are covered by the European Union. Other consortium participants will allocate 10% of the estimate.
Now the plan for the construction of the reactor, which will become the most expensive joint scientific project since, must be ratified by parliamentarians of the consortium member countries.
The reactor will be built in the southern French province of Provence, in the vicinity of the city of Cadarache, where the French nuclear research center is located.
Today, many countries are taking part in thermonuclear research. The leaders are the European Union, the United States, Russia and Japan, while programs in China, Brazil, Canada and Korea are rapidly expanding. Initially, fusion reactors in the USA and USSR were associated with the development of nuclear weapons and remained classified until the Atoms for Peace conference, which took place in Geneva in 1958. After the creation of the Soviet tokamak, nuclear fusion research became “big science” in the 1970s. But the cost and complexity of the devices increased to the point where international cooperation became the only way forward.
Thermonuclear reactors in the world
Since the 1970s, the beginning commercial use synthesis energy was constantly pushed back by 40 years. However, a lot has happened in recent years that may allow this period to be shortened.
Several tokamaks have been built, including the European JET, the British MAST and the TFTR experimental fusion reactor at Princeton, USA. International project ITER is currently under construction in Cadarache, France. It will be the largest tokamak when it starts operating in 2020. In 2030, China will build CFETR, which will surpass ITER. Meanwhile, China is conducting research on the experimental superconducting tokamak EAST.
Another type of fusion reactor, stellators, is also popular among researchers. One of the largest, LHD, began work in Japan National Institute in 1998. It is used to find the best magnetic configuration for plasma confinement. The German Max Planck Institute conducted research at the Wendelstein 7-AS reactor in Garching between 1988 and 2002, and currently at the Wendelstein 7-X reactor, whose construction took more than 19 years. Another TJII stellarator is in operation in Madrid, Spain. In the US, Princeton Laboratory (PPPL), which built the first fusion reactor of this type in 1951, stopped construction of NCSX in 2008 due to cost overruns and lack of funding.
In addition, significant advances have been made in inertial fusion research. Construction of the $7 billion National Ignition Facility (NIF) at Livermore National Laboratory (LLNL), funded by the National Nuclear Security Administration, was completed in March 2009. The French Laser Mégajoule (LMJ) began operations in October 2014. Fusion reactors use lasers delivering about 2 million joules of light energy within a few billionths of a second to a target a few millimeters in size to trigger a nuclear fusion reaction. The primary mission of NIF and LMJ is research in support of national military nuclear programs.
ITER
In 1985, the Soviet Union proposed to build a next-generation tokamak jointly 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 for the International Thermonuclear Experimental Reactor ITER, which also means "path" or "journey" in Latin, were created to prove that fusion could produce more energy than it absorbed. Canada and Kazakhstan also took part, mediated by Euratom and Russia respectively.
Six years later, the ITER board approved the first comprehensive reactor design based on established physics and technology, costing $6 billion. Then the United States withdrew from the consortium, which forced them to halve costs and change the project. The result is ITER-FEAT, which costs $3 billion but achieves self-sustaining response and positive power balance.
In 2003, the United States rejoined the consortium, and China announced its desire to participate. As a result, in mid-2005 the partners agreed to build ITER in Cadarache in the south of France. The EU and France contributed half of the €12.8 billion, while Japan, China, South Korea, USA and Russia - 10% each. Japan provided high-tech components, maintained a €1 billion IFMIF facility designed to test materials, and had the right to build the next test reactor. The total cost of ITER includes half the costs for 10 years of construction and half for 20 years of operation. India became the seventh member of ITER at the end of 2005.
Experiments are due to begin in 2018 using hydrogen to avoid activating the magnets. Usage D-T plasma not expected before 2026
ITER's goal 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 on an ongoing basis. The Demo's conceptual design will be completed by 2017, with construction to begin in 2024. The launch will take place in 2033.
JET
In 1978 the EU (Euratom, Sweden and Switzerland) started the joint European project JET in the UK. JET is today the largest operating tokamak in the world. A similar JT-60 reactor operates at Japan's National Fusion Institute, but only JET can use deuterium-tritium fuel.
The reactor was launched in 1983, and became the first experiment, which resulted in controlled thermonuclear fusion with a power of up to 16 MW for one second and 5 MW of stable power on deuterium-tritium plasma in November 1991. Many experiments have been carried out to study various heating schemes and other techniques.
Further improvements to the JET involve increasing its power. The MAST compact reactor is being developed together with JET and is part of the ITER project.
K-STAR
K-STAR is a Korean superconducting tokamak from the National Fusion Research Institute (NFRI) in Daejeon, which produced its first plasma in mid-2008. ITER, which is the result of international cooperation. The 1.8 m radius Tokamak is the first reactor to use Nb3Sn superconducting magnets, the same ones planned for ITER. During the first phase, completed by 2012, K-STAR had to prove the viability of the underlying technologies and achieve plasma pulses lasting up to 20 seconds. At the second stage (2013-2017), it is being modernized to study long pulses up to 300 s in H mode and transition to a high-performance AT mode. The goal of the third phase (2018-2023) is to achieve high productivity and efficiency in the long-pulse mode. At stage 4 (2023-2025), DEMO technologies will be tested. The device is not capable of working with tritium and does not use D-T fuel.
K-DEMO
Developed in collaboration with the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) and South Korea's NFRI, K-DEMO is intended to be the next step in commercial reactor development after ITER, and will be the first power plant capable of generating power into the electrical grid, namely 1 million kW within a few weeks. It will have a diameter of 6.65 m and will have a reproduction zone 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
China's Experimental Advanced Superconducting Tokamak (EAST) at the Institute of Physics of China in Hefei created hydrogen plasma at a temperature of 50 million °C and maintained it for 102 s.
TFTR
At the American laboratory PPPL, the experimental fusion reactor TFTR operated from 1982 to 1997. In December 1993, TFTR became the first magnetic tokamak to conduct extensive deuterium-tritium plasma experiments. IN next year the reactor produced a then-record 10.7 MW of controllable power, and in 1995 a temperature record of 510 million °C was achieved. However, the facility did not achieve the break-even goal of fusion energy, but successfully met the hardware design goals, making a significant contribution to the development of ITER.
LHD
The LHD at Japan's National Fusion Institute in Toki, Gifu Prefecture was the largest stellarator in the world. The fusion reactor was launched in 1998 and demonstrated plasma confinement properties 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 that began at the end of 2015, helium temperatures reached short time reached 1 million °C. In 2016, a hydrogen plasma fusion reactor using 2 MW of power reached a temperature of 80 million °C within a quarter of a second. W7-X is the largest stellarator in the world and is planned to operate continuously for 30 minutes. The cost of the reactor was 1 billion €.
NIF
The National Ignition Facility (NIF) at Livermore National Laboratory (LLNL) was completed in March 2009. Using your 192 laser beams,NIF is capable of concentrating 60 times more energy than any previous laser system.
Cold fusion
In March 1989, two researchers, American Stanley Pons and British Martin Fleischman, announced that they had launched a simple tabletop cold fusion reactor operating at room temperature. The process involved the electrolysis of heavy water using palladium electrodes on which deuterium nuclei were concentrated to a high density. The researchers claim that heat was produced that could only be explained in terms of nuclear processes, and there were by-products fusion, including helium, tritium and neutrons. However, other experimenters were unable 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 of "cold fusion", research has continued in the low-energy field with some empirical support, but no generally accepted scientific explanation. Apparently, weak nuclear interactions (rather than powerful force, as in or their synthesis). Experiments involve hydrogen or deuterium passing through a catalytic layer and reacting with a metal. Researchers report an observed release of energy. The main practical example is the interaction of hydrogen with nickel powder, releasing heat in an amount greater than any chemical reaction can produce.
Without exaggeration, the international experimental thermonuclear reactor ITER can be called the most significant research project of our time. In terms of the scale of construction, it will easily outshine the Large Hadron Collider, and if successful, it will mark a much bigger step for all of humanity than a flight to the Moon. Indeed, potentially controlled thermonuclear fusion is an almost inexhaustible source of unprecedentedly cheap and clean energy.
This summer there were several good reasons to brush up on the technical details of the ITER project. Firstly, a grandiose undertaking, the official start of which is considered to be the meeting between Mikhail Gorbachev and Ronald Reagan back in 1985, is taking on material embodiment before our eyes. Designing a new generation reactor with the participation of Russia, the USA, Japan, China, India, South Korea and the European Union took more than 20 years. Today, ITER is no longer kilograms of technical documentation, but 42 hectares (1 km by 420 m) of a perfectly flat surface of one of the world's largest man-made platforms, located in the French city of Cadarache, 60 km north of Marseille. As well as the foundation of the future 360,000-ton reactor, consisting of 150,000 cubic meters of concrete, 16,000 tons of reinforcement and 493 columns with rubber-metal anti-seismic coating. And, of course, thousands of sophisticated scientific instruments and research facilities scattered across universities around the world.
March 2007. First photo of the future ITER platform from the air.
Production of key reactor components is well underway. In the spring, France reported the production of 70 frames for D-shaped toroidal field coils, and in June, winding of the first coils of superconducting cables, received from Russia from the Institute of Cable Industry in Podolsk, began.
The second good reason to remember ITER right now is political. The new generation reactor is a test not only for scientists, but also for diplomats. This is such an expensive and technically complex project that no country in the world can undertake it alone. From the ability of states to agree among themselves both scientifically and financial sector depends on whether the matter can be completed.
March 2009. 42 hectares of leveled site are awaiting the start of construction of a scientific complex.
The ITER Council was scheduled for June 18 in St. Petersburg, but the US State Department, as part of sanctions, banned American scientists from visiting Russia. Taking into account the fact that the very idea of a tokamak (a toroidal chamber with magnetic coils, which is the basis of ITER) belongs to the Soviet physicist Oleg Lavrentiev, the project participants treated this decision as a curiosity and simply moved the meeting to Cadarache on the same date. These events once again reminded the whole world that Russia (along with South Korea) is most responsible for fulfilling its obligations to the ITER project.
February 2011. More than 500 holes were drilled in the seismic isolation shaft, all underground cavities were filled with concrete.
Scientists burn
The phrase “fusion reactor” makes many people wary. The associative chain is clear: a thermonuclear bomb is more terrible than just a nuclear one, which means that a thermonuclear reactor is more dangerous than Chernobyl.
In fact, nuclear fusion, on which the operating principle of the tokamak is based, is much safer and more efficient than nuclear fission used in modern nuclear power plants. Fusion is used by nature itself: the Sun is nothing more than a natural thermonuclear reactor.
The ASDEX tokamak, built in 1991 at Germany's Max Planck Institute, is used to test various reactor front wall materials, particularly tungsten and beryllium. The plasma volume in ASDEX is 13 m 3, almost 65 times less than in ITER.
The reaction involves nuclei of deuterium and tritium - isotopes of hydrogen. The deuterium nucleus consists of a proton and a neutron, and the tritium nucleus consists of a proton and two neutrons. Under normal conditions, equally charged nuclei repel each other, but at very high temperatures they can collide.
Upon collision, the strong interaction comes into play, which is responsible for combining protons and neutrons into nuclei. The nucleus of a new chemical element—helium—emerges. In this case, one free neutron is formed and a large amount of energy is released. The strong interaction energy in the helium nucleus is less than in the nuclei of the parent elements. Due to this, the resulting nucleus even loses mass (according to the theory of relativity, energy and mass are equivalent). Recalling the famous equation E = mc 2, where c is the speed of light, one can imagine the colossal energy potential nuclear fusion contains.
August 2011. The pouring of a monolithic reinforced concrete seismic isolating slab began.
To overcome the force of mutual repulsion, the original nuclei must move very quickly, so the key role in nuclear fusion temperature plays. At the center of the Sun, the process occurs at a temperature of 15 million degrees Celsius, but it is facilitated by the colossal density of matter due to the action of gravity. The colossal mass of the star makes it an effective thermonuclear reactor.
It is not possible to create such a density on Earth. All we can do is increase the temperature. For hydrogen isotopes to release the energy of their nuclei to earthlings, a temperature of 150 million degrees is required, that is, ten times higher than on the Sun.
No solid material in the Universe can come into direct contact with such a temperature. So just building a stove to cook helium won’t work. The same toroidal chamber with magnetic coils, or tokamak, helps solve the problem. The idea of creating a tokamak dawned on the bright minds of scientists from different countries in the early 1950s, while the primacy is clearly attributed to the Soviet physicist Oleg Lavrentyev and his eminent colleagues Andrei Sakharov and Igor Tamm.
A vacuum chamber in the shape of a torus (hollow donut) is surrounded by superconducting electromagnets, which create a toroidal magnetic field in it. It is this field that holds the plasma, hot up to ten times the sun, at a certain distance from the walls of the chamber. Together with the central electromagnet (inductor), the tokamak is a transformer. By changing the current in the inductor, they generate a current flow in the plasma - the movement of particles necessary for synthesis.
February 2012. 493 1.7-meter columns with seismic isolating pads made of rubber-metal sandwich were installed.
The Tokamak can rightfully be considered a model of technological elegance. Electric current, flowing in the plasma, creates a poloidal magnetic field that encircles the plasma cord and maintains its shape. Plasma exists under strictly defined conditions, and at the slightest change, the reaction immediately stops. Unlike a nuclear power plant reactor, a tokamak cannot “go wild” and increase the temperature uncontrollably.
In the unlikely event of destruction of the tokamak, there is no radioactive contamination. Unlike a nuclear power plant, a fusion reactor does not produce radioactive waste, and the only product of the fusion reaction, helium, is not greenhouse gas and useful in the household. Finally, the tokamak uses fuel very sparingly: during synthesis, only a few hundred grams of substance are contained in the vacuum chamber, and the estimated annual supply of fuel for an industrial power plant is only 250 kg.
April 2014. Construction of the cryostat building was completed, the walls of the 1.5-meter thick tokamak foundation were poured.
Why do we need ITER?
Tokamaks of the classical design described above were built in the USA and Europe, Russia and Kazakhstan, Japan and China. With their help, it was possible to prove the fundamental possibility of creating high-temperature plasma. However, building an industrial reactor capable of delivering more energy than it consumes is a task of a fundamentally different scale.
In a classic tokamak, the current flow in the plasma is created by changing the current in the inductor, and this process cannot be endless. Thus, the lifetime of the plasma is limited, and the reactor can only operate in pulsed mode. Ignition of plasma requires colossal energy - it’s no joke to heat anything to a temperature of 150,000,000 °C. This means that it is necessary to achieve a plasma lifetime that will produce energy that pays for ignition.
The fusion reactor is an elegant technical concept with minimal negative side effects. The flow of current in the plasma spontaneously forms a poloidal magnetic field that maintains the shape of the plasma filament, and the resulting high-energy neutrons combine with lithium to produce precious tritium.
For example, in 2009, during an experiment on the Chinese tokamak EAST (part of the ITER project), it was possible to maintain plasma at a temperature of 10 7 K for 400 seconds and 10 8 K for 60 seconds.
To hold the plasma longer, additional heaters of several types are needed. All of them will be tested at ITER. The first method - injection of neutral deuterium atoms - assumes that the atoms will enter the plasma pre-accelerated to a kinetic energy of 1 MeV using an additional accelerator.
This process is initially contradictory: only charged particles can be accelerated (they are affected by an electromagnetic field), and only neutral ones can be introduced into the plasma (otherwise they will affect the flow of current inside the plasma cord). Therefore, an electron is first removed from deuterium atoms, and positively charged ions enter the accelerator. The particles then enter the neutralizer, where they are reduced to neutral atoms by interacting with the ionized gas and introduced into the plasma. The ITER megavoltage injector is currently being developed in Padua, Italy.
The second heating method has something in common with heating food in the microwave. It involves effects on plasma electromagnetic radiation with a frequency corresponding to the speed of particle movement (cyclotron frequency). For positive ions this frequency is 40−50 MHz, and for electrons it is 170 GHz. To create powerful radiation of such a high frequency, a device called a gyrotron is used. Nine of the 24 ITER gyrotrons are manufactured at the Gycom facility in Nizhny Novgorod.
The classical concept of a tokamak assumes that the shape of the plasma column is supported by a poloidal magnetic field, which is formed by itself when current flows in the plasma. This approach is not applicable for long-term plasma confinement. The ITER tokamak has special poloidal field coils, the purpose of which is to keep the hot plasma away from the walls of the reactor. These coils are among the most massive and complex structural elements.
In order to be able to actively control the shape of the plasma, promptly eliminating vibrations at the edges of the cord, the developers provided small, low-power electromagnetic circuits located directly in the vacuum chamber, under the casing.
Fuel infrastructure for thermonuclear fusion is a separate interesting topic. Deuterium is found in almost any water, and its reserves can be considered unlimited. But the world's reserves of tritium amount to tens of kilograms. 1 kg of tritium costs about $30 million. For the first launches of ITER, 3 kg of tritium will be needed. By comparison, about 2 kg of tritium per year is needed to maintain the nuclear capabilities of the United States Army.
However, in the future, the reactor will provide itself with tritium. The main fusion reaction produces high-energy neutrons that are capable of converting lithium nuclei into tritium. The development and testing of the first reactor wall containing lithium is one of ITER's most important goals. The first tests will use beryllium-copper cladding, the purpose of which is to protect the reactor mechanisms from heat. According to calculations, even if we transfer the entire energy sector of the planet to tokamaks, the world's lithium reserves will be enough for a thousand years of operation.
Preparing the 104-kilometer ITER Path cost France 110 million euros and four years of work. The road from the port of Fos-sur-Mer to Cadarache was widened and strengthened so that the heaviest and largest parts of the tokamak could be transported to the site. In the photo: a transporter with a test load weighing 800 tons.
From the world via tokamak
Precision control of a fusion reactor requires precise diagnostic tools. One of the key tasks of ITER is to select the most suitable of the five dozen instruments that are currently being tested, and to begin the development of new ones.
At least nine diagnostic devices will be developed in Russia. Three are at the Moscow Kurchatov Institute, including a neutron beam analyzer. The accelerator sends a focused stream of neutrons through the plasma, which undergoes spectral changes and is captured by the receiving system. Spectrometry with a frequency of 250 measurements per second shows the temperature and density of the plasma, force electric field and particle rotation speed are parameters necessary to control the reactor for long-term plasma confinement.
Three instruments are being prepared by the Ioffe Research Institute, including a neutral particle analyzer that captures atoms from the tokamak and helps monitor the concentration of deuterium and tritium in the reactor. The remaining devices will be made at Trinity, where diamond detectors for the ITER vertical neutron chamber are currently being manufactured. All of the above institutes use their own tokamaks for testing. And in the thermal chamber of the Efremov NIIEFA, fragments of the first wall and the diverter target of the future ITER reactor are being tested.
Unfortunately, the fact that many of the components of a future mega-reactor already exist in the metal does not necessarily mean that the reactor will be built. Over the past decade, the estimated cost of the project has grown from 5 to 16 billion euros, and the planned first launch has been postponed from 2010 to 2020. The fate of ITER depends entirely on the realities of our present, primarily economic and political. Meanwhile, every scientist involved in the project sincerely believes that its success can change our future beyond recognition.
Humanity is gradually approaching the border of irreversible depletion of the Earth's hydrocarbon resources. We have been extracting oil, gas and coal from the bowels of the planet for almost two centuries, and it is already clear that their reserves are being depleted at tremendous speed. The leading countries of the world have long been thinking about creating a new source of energy, environmentally friendly, safe from the point of view of operation, with enormous fuel reserves.
Fusion reactor
Today there is a lot of talk about the use of so-called alternative types of energy - renewable sources in the form of photovoltaics, wind energy and hydropower. It is obvious that, due to their properties, these directions can only act as auxiliary sources of energy supply.
As a long-term prospect for humanity, only energy based on nuclear reactions.
On the one hand, more and more states are showing interest in building nuclear reactors on their territory. But still, a pressing problem for nuclear energy is the processing and disposal of radioactive waste, and this affects economic and environmental indicators. Back in the middle of the 20th century, the world's leading physicists, in search of new types of energy, turned to the source of life on Earth - the Sun, in the depths of which, at a temperature of about 20 million degrees, reactions of synthesis (fusion) of light elements take place with the release of colossal energy.
Domestic specialists handled the task of developing a facility for implementing nuclear fusion reactions under terrestrial conditions best of all. The knowledge and experience in the field of controlled thermonuclear fusion (CTF), obtained in Russia, formed the basis of the project, which is, without exaggeration, the energy hope of humanity - the International Experimental Thermonuclear Reactor (ITER), which is being built in Cadarache (France).
History of thermonuclear fusion
The first thermonuclear research began in countries working on their atomic defense programs. This is not surprising, because at the dawn of the atomic era, the main purpose of the appearance of deuterium plasma reactors was research physical processes in hot plasma, knowledge of which was necessary, among other things, for the creation of thermonuclear weapons. According to declassified data, the USSR and the USA began almost simultaneously in the 1950s. work on UTS. But, at the same time, there is historical evidence that back in 1932, the old revolutionary and close friend of the leader of the world proletariat Nikolai Bukharin, who at that time held the post of chairman of the Supreme Economic Council committee and followed the development of Soviet science, proposed to launch a project in the country to study controlled thermonuclear reactions.
The history of the Soviet thermonuclear project is not without a fun fact. The future famous academician and creator of the hydrogen bomb, Andrei Dmitrievich Sakharov, was inspired by the idea of magnetic thermal insulation of high-temperature plasma from a letter from a Soviet army soldier. In 1950, Sergeant Oleg Lavrentyev, who served on Sakhalin, sent a letter to the Central Committee of the All-Union Communist Party in which he proposed using lithium-6 deuteride instead of liquefied deuterium and tritium in a hydrogen bomb, and also creating a system with electrostatic confinement of hot plasma to carry out controlled thermonuclear fusion . The letter was reviewed by the then young scientist Andrei Sakharov, who wrote in his review that he “considers it necessary to have a detailed discussion of Comrade Lavrentiev’s project.”
Already by October 1950, Andrei Sakharov and his colleague Igor Tamm made the first estimates of a magnetic thermonuclear reactor (MTR). The first toroidal installation with a strong longitudinal magnetic field, based on the ideas of I. Tamm and A. Sakharov, was built in 1955 in LIPAN. It was called TMP - a torus with a magnetic field. Subsequent installations were already called TOKAMAK, after the combination of the initial syllables in the phrase “TORIDAL CHAMBER MAGNETIC COIL”. In his classic version A tokamak is a donut-shaped toroidal chamber placed in a toroidal magnetic field. From 1955 to 1966 At the Kurchatov Institute, 8 such installations were built, on which a lot of different studies were carried out. If before 1969, a tokamak was built outside the USSR only in Australia, then in subsequent years they were built in 29 countries, including the USA, Japan, European countries, India, China, Canada, Libya, Egypt. In total, about 300 tokamaks have been built in the world to date, including 31 in the USSR and Russia, 30 in the USA, 32 in Europe and 27 in Japan. In fact, three countries - the USSR, Great Britain and the USA - were engaged in an unspoken competition to see who would be the first to harness plasma and actually begin producing energy “from water.”
The most important advantage of a thermonuclear reactor is the reduction in radiation biological hazard by approximately a thousand times in comparison with all modern nuclear power reactors.
A thermonuclear reactor does not emit CO2 and does not produce “heavy” radioactive waste. This reactor can be placed anywhere, anywhere.
A step of half a century
In 1985, academician Evgeniy Velikhov, on behalf of the USSR, proposed that scientists from Europe, the USA and Japan work together to create a thermonuclear reactor, and already in 1986 in Geneva an agreement was reached on the design of the installation, which later received the name ITER. In 1992, the partners signed a quadripartite agreement to develop an engineering design for the reactor. The first stage of construction is scheduled to be completed by 2020, when it is planned to receive the first plasma. In 2011, real construction began at the ITER site.
The ITER design follows the classic Russian tokamak, developed back in the 1960s. It is planned that at the first stage the reactor will operate in a pulsed mode with a power of thermonuclear reactions of 400–500 MW, at the second stage the continuous operation of the reactor, as well as the tritium reproduction system, will be tested.
It is not for nothing that the ITER reactor is called the energy future of humanity. Firstly, it is the world's largest science project, because on the territory of France it is being built by almost the entire world: the EU + Switzerland, China, India, Japan, South Korea, Russia and the USA are participating. The agreement on the construction of the installation was signed in 2006. European countries contribute about 50% of the project's financing, Russia accounts for approximately 10% of the total amount, which will be invested in the form of high-tech equipment. But Russia’s most important contribution is the tokamak technology itself, which formed the basis of the ITER reactor.
Secondly, this will be the first large-scale attempt to use the thermonuclear reaction that occurs in the Sun to generate electricity. Thirdly, this scientific work should bring very practical results, and by the end of the century the world expects the appearance of the first prototype of a commercial thermonuclear power plant.
Scientists assume that the first plasma at the international experimental thermonuclear reactor will be produced in December 2025.
Why did literally the entire world scientific community begin to build such a reactor? The fact is that many technologies that are planned to be used in the construction of ITER do not belong to all countries at once. One state, even the most highly developed in scientific and technical terms, cannot immediately have a hundred technologies of the highest world level in all fields of technology used in such a high-tech and breakthrough project as a thermonuclear reactor. But ITER consists of hundreds of similar technologies.
Russia surpasses the global level in many thermonuclear fusion technologies. But, for example, Japanese nuclear scientists also have unique competencies in this area, which are quite applicable in ITER.
Therefore, at the very beginning of the project, the partner countries came to agreements about who and what would supply to the site, and that this should not just be cooperation in engineering, but an opportunity for each of the partners to receive new technologies from other participants, so that in the future develop them yourself.
Andrey Retinger, international journalist
