International thermonuclear reactor. The road to the sun - the worldwide construction of a fusion reactor in France. Cold nuclear fusion

ITER - International Thermonuclear Reactor (ITER)

Energy consumption by mankind is growing every year, which pushes the energy sector to active development. So with the advent of nuclear power plants, the amount of energy generated around the world has increased significantly, which made it possible to safely use energy for all the needs of mankind. For example, 72.3% of the electricity generated in France comes from nuclear power plants, in Ukraine - 52.3%, in Sweden - 40.0%, in the UK - 20.4%, in Russia - 17.1%. However, technology does not stand still, and in order to cater to the further energy needs of the countries of the future, scientists are working on a number of innovative projects, one of which is ITER - International Thermonuclear Experimental Reactor (ITER, International Thermonuclear Experimental Reactor).

Although the profitability of this facility is still in question, according to the work of many researchers, the creation and subsequent development of controlled thermonuclear fusion technology can result in a powerful and safe source of energy. Consider some of the positive aspects of such an installation:

• The main fuel of a thermonuclear reactor is hydrogen, which means practically inexhaustible reserves of nuclear fuel.
• Hydrogen production can occur through the processing of sea water, which is available to most countries. This implies the impossibility of the emergence of a monopoly of fuel resources.
• The probability of an accidental explosion during the operation of a thermonuclear reactor is much less than during the operation of a nuclear reactor. According to researchers, even in the event of an accident, radiation emissions will not pose a danger to the population, which means there is no need for evacuation.
• Unlike nuclear reactors, fusion reactors produce radioactive waste that has a short half-life, meaning it decays faster. Also in thermonuclear reactors there are no products of combustion.
• The operation of a fusion reactor does not require materials that are also used for nuclear weapons. This makes it possible to exclude the possibility of covering up the production of nuclear weapons by processing materials for the needs of a nuclear reactor.

Fusion reactor - inside view

However, there are also a number of technical shortcomings that researchers constantly encounter.

For example, the current version of the fuel, presented in the form of a mixture of deuterium and tritium, requires the development of new technologies. For example, at the end of the first series of tests at the JET, the largest fusion reactor to date, the reactor became so radioactive that further development of a special robotic maintenance system was required to complete the experiment. Another disappointing factor in the operation of a thermonuclear reactor is its efficiency - 20%, while the efficiency of nuclear power plants is 33-34%, and thermal power plants - 40%.

Creation of the ITER project and launch of the reactor

The ITER project started in 1985 when Soviet Union proposed the joint creation of a tokamak - a toroidal chamber with magnetic coils, which is capable of holding the plasma with the help of magnets, thereby creating the conditions required for the fusion reaction to proceed. In 1992, a quadripartite agreement on the development of ITER was signed, the parties to which were the EU, USA, Russia and Japan. The Republic of Kazakhstan joined the project in 1994, Canada in 2001, South Korea and China in 2003, and India in 2005. In 2005, the site for the construction of the reactor was determined - the research center for nuclear energy Cadarache, France.

The construction of the reactor began with the preparation of a foundation pit. So the parameters of the pit were 130 x 90 x 17 meters. The entire complex with the tokamak will weigh 360,000 tons, of which 23,000 tons will be the tokamak itself.

Various elements of the ITER complex will be developed and delivered to the construction site from all over the world. So in 2016, part of the conductors for poloidal coils was developed in Russia, which then went to China, which will produce the coils themselves.

Obviously, such a large-scale work is not at all easy to organize, a number of countries have repeatedly failed to keep up with the set project schedule, as a result of which the launch of the reactor has been constantly postponed. So, according to last year's (2016) June message: "obtaining the first plasma is scheduled for December 2025."

The mechanism of operation of the ITER tokamak

The term "tokamak" comes from a Russian acronym which means "toroidal chamber with magnetic coils".

The heart of the tokamak is its torus-shaped vacuum chamber. Inside, under the influence of extreme temperature and pressure, gaseous hydrogen fuel becomes a plasma - a hot electrically charged gas. As is known, stellar matter is represented by plasma, and thermonuclear reactions in the core of the Sun occur precisely under conditions of elevated temperature and pressure. Similar conditions for the formation, retention, compression and heating of the plasma are created by means of massive magnetic coils, which are located around the vacuum vessel. The impact of magnets will limit the hot plasma from the walls of the vessel.

Before starting the process, air and impurities are removed from the vacuum chamber. Magnetic systems are then charged to help control the plasma, and gaseous fuel is injected. When a powerful electric current passes through the vessel, the gas is electrically split and becomes ionized (that is, the electrons leave the atoms) and forms a plasma.

As the plasma particles are activated and collide, they also begin to heat up. Auxiliary heating techniques help to bring the plasma to temperatures between 150 and 300 million °C. Particles "excited" to this extent can overcome their natural electromagnetic repulsion when colliding, and huge amounts of energy are released as a result of such collisions.

The design of the tokamak consists of the following elements:

vacuum vessel

("donut") - a toroidal chamber made of stainless steel. Its large diameter is 19 m, small - 6 m, and height - 11 m. The volume of the chamber is 1,400 m 3, and its mass is more than 5,000 tons. water. In order to avoid water contamination, the inner wall of the chamber is protected from radioactive radiation by means of a blanket.

Blanket

("blanket") - consists of 440 fragments covering the inner surface of the chamber. The total area of ​​the banquet is 700m 2 . Each fragment is a kind of cassette, the body of which is made of copper, and the front wall is removable and made of beryllium. The parameters of the cassettes are 1x1.5 m, and the mass is no more than 4.6 tons. Such beryllium cassettes will slow down the high-energy neutrons produced during the reaction. During neutron moderation, heat will be released, which is removed by the cooling system. It should be noted that the beryllium dust generated as a result of the operation of the reactor can cause a serious disease called berylliosis, and also has a carcinogenic effect. For this reason, strict security measures are being developed in the complex.

Tokamak in section. Yellow - solenoid, orange - toroidal field (TF) and poloidal field (PF) magnets, blue - blanket, light blue - VV - vacuum vessel, purple - divertor

(“ashtray”) of a poloidal type is a device whose main task is to “cleanse” the plasma from dirt resulting from the heating and interaction of the chamber walls covered with a blanket with it. When such contaminants enter the plasma, they begin to radiate intensely, as a result of which additional radiation losses occur. It is located in the lower part of the tokomak and with the help of magnets directs the upper layers of the plasma (which are the most contaminated) into the cooling chamber. Here, the plasma cools and turns into a gas, after which it is pumped back out of the chamber. Beryllium dust, after entering the chamber, is practically unable to return back to the plasma. Thus, plasma contamination remains only on the surface and does not penetrate deep into.

Cryostat

- the largest component of the tokomak, which is a stainless steel shell with a volume of 16,000 m 2 (29.3 x 28.6 m) and a mass of 3,850 tons. Other elements of the system will be located inside the cryostat, and it itself will serve as a barrier between the tokamak and the external environment. On its inner walls there will be heat shields cooled by circulating nitrogen at a temperature of 80 K (-193.15 °C).

Magnetic system

- a complex of elements that serve to contain and control the plasma inside the vacuum vessel. It is a set of 48 elements:

• Toroidal field coils are located outside the vacuum chamber and inside the cryostat. Presented in the amount of 18 pieces, each of which is 15 x 9 m in size and weighs approximately 300 tons. Together, these coils generate a magnetic field of 11.8 T around the plasma torus and store energy of 41 GJ.
• Poloidal field coils - located on top of the toroidal field coils and inside the cryostat. These coils are responsible for the formation of a magnetic field that separates the plasma mass from the chamber walls and compresses the plasma for adiabatic heating. The number of such coils is 6. Two of the coils have a diameter of 24 m and a mass of 400 tons. The remaining four are somewhat smaller.
• The central solenoid is located in the inside of the toroidal chamber, or rather in the “donut hole”. The principle of its operation is similar to a transformer, and the main task is to excite the inductive current in the plasma.
• Correction coils are located inside the vacuum vessel, between the blanket and the chamber wall. Their task is to preserve the shape of the plasma, capable of locally "bulging" and even touching the walls of the vessel. Allows to reduce the level of interaction of the chamber walls with the plasma, and hence the level of its contamination, and also reduces the wear of the chamber itself.

Structure of the ITER complex

The above-described "in a nutshell" design of the tokamak is a complex innovative mechanism, assembled by the efforts of several countries. However, for its full-fledged operation, a whole complex of buildings located near the tokamak is required. Among them:

• Control, Data Access and Communication System - CODAC. It is located in a number of buildings of the ITER complex.
• Fuel storage and fuel system - serves to deliver fuel to the tokamak.
• Vacuum system - consists of more than four hundred vacuum pumps, whose task is to pump out the products of a thermonuclear reaction, as well as various contaminants from the vacuum chamber.
• Cryogenic system - represented by a nitrogen and helium circuit. The helium circuit will normalize the temperature in the tokamak, the work (and hence the temperature) of which does not proceed continuously, but in impulses. The nitrogen circuit will cool the thermal screens of the cryostat and the helium circuit itself. There will also be a water cooling system, which is aimed at lowering the temperature of the blanket walls.
• Power supply. The tokamak will require approximately 110 MW of power to operate continuously. For this, power lines per kilometer will be laid, which will be connected to the French industrial network. It is worth recalling that the ITER experimental facility does not provide for energy generation, but works only in scientific interests.

ITER financing

The international thermonuclear reactor ITER is a rather expensive undertaking, which was originally estimated at 12 billion dollars, where Russia, the USA, Korea, China and India account for 1/11 of the amount, Japan - 2/11, and the EU - 4/11 . Later this amount increased to 15 billion dollars. It is noteworthy that financing occurs through the supply of equipment required for the complex, which is developed in each of the countries. Thus, Russia supplies blankets, plasma heating devices and superconducting magnets.

Project perspective

At the moment, the ITER complex is being built and all the required components for the tokamak are being produced. After the planned launch of the tokamak in 2025, a series of experiments will begin, based on the results of which aspects that need improvement will be noted. After the successful commissioning of ITER, it is planned to build a power plant based on thermonuclear fusion called DEMO (DEMOnstration Power Plant). DEMo's mission is to demonstrate the so-called "commercial appeal" of fusion energy. If ITER is capable of generating only 500 MW of energy, then DEMO will allow continuous generation of 2 GW of energy.

However, it should be borne in mind that the ITER experimental facility will not generate energy, and its purpose is to obtain a purely scientific benefit. And as you know, this or that physical experiment can not only justify expectations, but also bring new knowledge and experience to mankind.

Today many countries take part in thermonuclear research. The leaders are the European Union, the USA, Russia and Japan, while the programs of China, Brazil, Canada and Korea are growing rapidly. Initially, fusion reactors in the US 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 a "big science". But the cost and complexity of the devices has increased to the point where international cooperation has become the only way forward.

Thermonuclear reactors in the world

Beginning in the 1970s, the commercial use of fusion energy was constantly pushed back by 40 years. However, much has happened in recent years, due to which this period can be reduced.

Several tokamaks have been built, including the European JET, the British MAST, and the experimental fusion reactor TFTR at Princeton, USA. The international ITER project is currently under construction in Cadarache, France. It will become the largest tokamak when it is operational in 2020. In 2030, CFETR will be built in China, which will surpass ITER. Meanwhile, the PRC is conducting research on the EAST experimental superconducting tokamak.

Fusion reactors of another type - stellators - are also popular with researchers. One of the largest, LHD, began work at the Japanese National Institute in 1998. It is used to find the best magnetic plasma confinement configuration. The German Max Planck Institute carried out research on the Wendelstein 7-AS reactor in Garching between 1988 and 2002, and currently on the Wendelstein 7-X, which has been under construction for more than 19 years. Another TJII stellarator is in operation in Madrid, Spain. In the US, the Princeton Laboratory (PPPL), where the first fusion reactor of this type was built in 1951, halted construction of the NCSX in 2008 due to cost overruns and lack of funding.

In addition, significant progress has been made in research into inertial thermonuclear fusion. 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 operation in October 2014. Fusion reactors use about 2 million joules of light energy delivered by lasers in a few billionths of a second to a target a few millimeters in size to start a nuclear fusion reaction. The main task of the NIF and LMJ is research to support national military nuclear programs.

ITER

In 1985, the Soviet Union proposed to build the next generation tokamak in cooperation 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 could absorb. Canada and Kazakhstan also participated, mediated by Euratom and Russia, respectively.

Six years later, the ITER board approved the first comprehensive reactor project based on established physics and technology, worth $6 billion. Then the US withdrew from the consortium, which forced them to halve costs and change the project. The result was ITER-FEAT, costing $3 billion but achieving 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 ITER in Cadarache in southern France. The EU and France contributed half of the €12.8bn, while Japan, China, South Korea, the US and Russia contributed 10% each. Japan provided high-tech components, hosted the €1 billion IFMIF facility for materials testing, and had the right to build the next test reactor. The total cost of ITER includes half the cost of 10 years of construction and half of the cost of 20 years of operation. India became the seventh member of ITER at the end of 2005.

Experiments should start in 2018 using hydrogen to avoid magnet activation. Using D-T plasma 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 on a continuous basis. Demo's concept 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 a joint European JET project in the UK. JET is the largest operating tokamak in the world today. A similar JT-60 reactor operates at Japan's National Fusion Fusion Institute, 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 thermonuclear fusion with a power of up to 16 MW for one second and 5 MW of stable power was carried out on a deuterium-tritium plasma. Many experiments have been carried out in order to study various heating schemes and other techniques.

Further improvements to the JET are to increase 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 as those planned to be used in ITER. During the first stage, completed by 2012, K-STAR had to prove the viability of the basic technologies and achieve plasma pulses with a duration of up to 20 s. At the second stage (2013-2017), it is being upgraded to study long pulses up to 300 s in the H mode and transition to the high-performance AT mode. The goal of the third phase (2018-2023) is to achieve high performance and efficiency in the continuous pulse mode. At the 4th stage (2023-2025), DEMO technologies will be tested. The device is not tritium capable and does not use D-T fuel.

K-DEMO

Developed in collaboration with the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) and South Korea's NFRI, K-DEMO is set 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 being 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 Chinese Institute of Physics in Hefei created a hydrogen plasma at a temperature of 50 million °C and held it for 102 seconds.

TFTR

In the American laboratory PPPL, the experimental fusion reactor TFTR operated from 1982 to 1997. In December 1993, TFTR became the first magnetic tokamak to carry out extensive experiments with deuterium-tritium plasma. The following year, the reactor produced a then-record 10.7 MW of controllable power, and in 1995 a temperature record of 510 million °C was reached. However, the facility did not achieve the goal of break-even 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 Fusion Institute in Toki, Gifu Prefecture was the largest stellarator in the world. The fusion reactor was launched in 1998 and has 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 was reached.

Wendelstein 7-X

After a year of testing that began at the end of 2015, the helium temperature briefly 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 its 192 laser beams, NIF is able to concentrate 60 times more energy than any previous laser system.

Cold nuclear fusion

In March 1989, two researchers, American Stanley Pons and Briton Martin Fleischman, announced that they had launched a simple tabletop cold fusion reactor operating at room temperature. The process consisted in the electrolysis of heavy water using palladium electrodes, on which deuterium nuclei were concentrated at a high density. The researchers claim that heat was produced that could only be explained in terms of nuclear processes, and there were fusion by-products including helium, tritium and neutrons. However, other experimenters failed to repeat this experience. 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 into the low-energy field with some empirical support but no generally accepted scientific explanation. Apparently, weak nuclear interactions are used to create and capture neutrons (and not a powerful force, as in or their synthesis). Experiments involve permeating hydrogen or deuterium through a catalytic bed and reacting with a metal. The 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.

ITER (ITER, International Thermonuclear Experimental Reactor, "International Experimental Thermonuclear Reactor") is a large-scale scientific and technical project aimed at building the first international experimental thermonuclear reactor.

Implemented by seven main partners (European Union, India, China, Republic of Korea, Russia, USA, Japan) in Cadarache (Provence-Alpes-Côte d'Azur region, France). ITER is based on the tokamak facility (named after the first letters: toroidal chamber with magnetic coils), which is considered the most promising device for controlled thermonuclear fusion. The first tokamak was built in the Soviet Union in 1954.

The aim of the project is to demonstrate that fusion energy can be used on an industrial scale. ITER is supposed to generate energy by fusion reaction with heavy hydrogen isotopes at a temperature of more than 100 million degrees.

It is assumed that 1 g of fuel (a mixture of deuterium and tritium), which will be used in the installation, will give the same amount of energy as 8 tons of oil. Estimated thermonuclear power of ITER is 500 MW.

Experts say that a reactor of this type is much safer than current nuclear power plants (NPPs), and sea water can provide fuel for it in almost unlimited quantities. Thus, the successful implementation of ITER will provide an inexhaustible source of clean energy.

Project history

The concept of the reactor was developed at the Institute of Atomic Energy. I.V. Kurchatov. In 1978, the USSR put forward the idea of ​​implementing a project at the International Atomic Energy Agency (IAEA). An agreement on the implementation of the project was reached in 1985 in Geneva during negotiations between the USSR and the USA.

The program was later approved by the IAEA. In 1987, the project received its current name, in 1988 the governing body, the ITER Council, was established. In 1988-1990. Soviet, American, Japanese and European scientists and engineers carried out a conceptual study of the project.

On July 21, 1992 in Washington, the EU, Russia, the USA and Japan signed an agreement on the development of the ITER technical project, which was completed in 2001. In 2002-2005. South Korea, China and India joined the project. The agreement on the construction of the first international experimental thermonuclear reactor was signed in Paris on November 21, 2006.

A year later, on November 7, 2007, an agreement was signed on the ITER construction site, according to which the reactor will be located in France, at the Cadarache nuclear center near Marseille. The control and data processing center will be located in Naka (Ibaraki Prefecture, Japan).

Site preparation in Cadarache began in January 2007, and full-scale construction began in 2013. The complex will be located on an area of ​​180 hectares. The reactor with a height of 60 m and a mass of 23 thousand tons will be located on a site 1 km long and 400 m wide. Work on its construction is coordinated by the International Organization ITER, established in October 2007.

The cost of the project is estimated at 15 billion euros, of which the EU (through Euratom) accounts for 45.4%, and six other participants (including the Russian Federation) contribute 9.1% each. Since 1994, Kazakhstan has also been participating in the project under the Russian quota.

The elements of the reactor will be delivered by ships to the Mediterranean coast of France and from there transported by special caravans to the Cadarache region. To this end, in 2013, sections of existing roads were significantly re-equipped, bridges were strengthened, new crossings and roads with especially strong surface were built. In the period from 2014 to 2019, at least three dozen super-heavy road trains should pass along the reinforced road.

Plasma diagnostic systems for ITER will be developed in Novosibirsk. An agreement on this was signed on January 27, 2014 by Osamu Motojima, Director of the International Organization ITER, and Anatoly Krasilnikov, Head of the ITER National Agency in the Russian Federation.

The development of the diagnostic complex under the new agreement is being carried out on the basis of the Physico-Technical Institute. A. F. Ioffe Russian Academy Sciences.

It is expected that the reactor will be put into operation in 2020, the first reactions for nuclear fusion will be carried out on it no earlier than 2027. In 2037, it is planned to complete the experimental part of the project and by 2040 switch to electricity generation. According to preliminary forecasts of experts, the industrial version of the reactor will be ready no earlier than 2060, and a series of reactors of this type can be created only by the end of the 21st century.

For a long time trudnopisaka asked to make a post about a fusion reactor under construction. Learn interesting details of the technology, find out why this project is taking so long to be implemented. Finally got the material. Let's get acquainted with the details of the project.

How it all started. The “energy challenge” arose as a result of a combination of the following three factors:

1. Humanity now consumes a huge amount of energy.

The world's current energy consumption is about 15.7 terawatts (TW). Dividing this value by the population of the planet, we get about 2400 watts per person, which can be easily estimated and imagined. 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 around the planet is very uneven, as it is very high in several countries and negligible in others. Consumption (in terms of one person) is 10.3 kW in the USA (one of the record values), 6.3 kW in Russian Federation, 5.1 kW in the UK, etc., but on the other hand, it is only 0.21 kW in Bangladesh (only 2% of the US consumption!).

According to the forecast of the International Energy Agency (2006), world energy consumption should increase by 50% by 2030. Developed countries, of course, could do just fine without additional energy, but this growth is necessary to lift the population of developing countries, where 1.5 billion people are suffering from an acute shortage of electrical energy, out of poverty.

3. Currently, 80% of the world's energy is generated by burning fossil fuels(oil, coal and gas), the use of which:
a) potentially carries the risk of catastrophic environmental changes;
b) must inevitably end someday.

From what has been said, it is clear that already now we must prepare for the end of the era of the use of fossil fuels.

At present, nuclear power plants receive on a large scale the energy released during the fission reactions of atomic nuclei. The creation and development of such stations should be encouraged in every possible way, but it should be taken into account that the reserves of one of the most important material for their operation (cheap uranium) can also be completely used up over 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, which can almost double the amount of energy produced. For the development of energy in this direction, it is necessary to create reactors on thorium (the so-called thorium breeder reactors or breeder reactors), in which more thorium is produced during the reaction than the original uranium, as a result of which the total amount of energy received for a given amount of substance increases by 40 times . It also seems promising to create fast-neutron plutonium breeders, which are much more efficient than uranium reactors and make it possible to obtain 60 times more energy. Perhaps, for the development of 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 the principle of operation 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 fall into 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 with the formation of 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) be a nuclear fusion reaction that would produce tritium. In this case, the amount of tritium formed should not only meet the needs of the installation itself, but even be somewhat larger, which will make it possible to provide new installations with tritium. It is this operating concept that must be tested and implemented in the ITER reactor described below.

In addition, the neutrons must heat the shell in the so-called pilot plants (which will use relatively "ordinary" structural materials) to a temperature of 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 released 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 vapor is produced and supplied to the turbines.

1985 - The Soviet Union proposed the next generation Tokamak plant, using the experience of the four leading countries in the creation of thermonuclear reactors. The United States of America, together with Japan and the European Community, put forward a proposal for the implementation of the project.

France is currently building the International Tokamak Experimental Reactor (ITER), described below, which will be the first tokamak capable of "igniting" plasma.

The most advanced tokamak-type facilities in existence have long reached temperatures of the order of 150 M°C, close to those required for the operation of a fusion plant, but the 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 the parameters of its operation, which will require, first of all, an increase in the pressure in the plasma, since the rate of nuclear fusion at a given temperature is proportional to the square of the pressure. The main scientific problem in this case is related to the fact that when the pressure in the plasma increases, very complex and dangerous instabilities arise, that is, unstable modes of operation.

Why do we need it?

The main advantage of nuclear fusion is that it requires only a very small amount of naturally occurring substances as fuel. The nuclear fusion reaction in the described installations can lead to the release of huge amounts of energy, ten million times higher than the standard heat release in conventional chemical reactions(such as burning fossil fuels). For comparison, we point out that the amount of coal required to operate 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 capacity will consume only about 1 kilogram of a D + T mixture per day. .

Deuterium is a stable isotope of hydrogen; in about one out of every 3350 molecules of ordinary water, one of the hydrogen atoms is replaced by deuterium (a legacy inherited from 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 arise directly inside the fusion plant during operation, due to the reaction of neutrons with lithium.

Thus, the initial fuel for a thermonuclear reactor is lithium and water. Lithium is a common metal widely used in household appliances (mobile phone batteries, etc.). The plant described above, even with imperfect 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 required amount of lithium is contained in one computer battery, and the amount of deuterium is contained in 45 liters of water. The above value corresponds to the current consumption of electricity (in terms of one person) in the EU countries for 30 years. The very fact that such an insignificant amount of lithium can provide the generation of such an amount of electricity (without CO2 emissions and without the slightest pollution of the atmosphere) is a sufficiently serious argument for the rapid and vigorous development of thermonuclear energy (despite all the difficulties and problems) and even without one hundred percent certainty in the success of such research.

Deuterium should last for millions of years, and easily mined lithium reserves are quite sufficient to meet the needs for hundreds of years. Even if we run out of lithium in rocks, we can extract it from the water, where it is found in a high enough concentration (100 times that of uranium) to make it economically viable to mine.

An experimental thermonuclear reactor (International thermonuclear experimental reactor) is being built near the city of Cadarache in France. The main task of the ITER project is the implementation of a controlled thermonuclear fusion reaction on an industrial scale.

Per unit weight of thermonuclear fuel, about 10 million times more energy is obtained than by burning the same amount of organic fuel, and about a hundred times more than by fissioning uranium nuclei in the reactors of currently operating nuclear power plants. If the calculations of scientists and designers are justified, this will give humanity an inexhaustible source of energy.

Therefore, a number of countries (Russia, India, China, Korea, Kazakhstan, USA, Canada, Japan, EU countries) joined their efforts in creating the International Thermonuclear Research Reactor - a prototype of new power plants.

ITER is an installation that creates conditions for the synthesis of hydrogen atoms and tritium (an isotope of hydrogen), resulting in the formation of new atom is a helium atom. This process is accompanied by a huge surge of energy: the temperature of the plasma in which the thermonuclear reaction takes place is about 150 million degrees Celsius (for comparison, the temperature of the core of the Sun is 40 million degrees). In this case, the isotopes burn out, leaving practically 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 environment. It can be located almost anywhere in the world, and ordinary water serves as fuel for it. Construction of ITER should take about ten years, after which the reactor is supposed to be used for 20 years.

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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, the Institute of Crystallography of the Russian Academy of Sciences and Scientific Secretary of the Presidential Council for Science, Technology and Education. Kovalchuk will temporarily replace Academician Yevgeny Velikhov in this post, who has been elected Chairman of the International Council of ITER for the next two years 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 the trial operation of the reactor. The shares of India, China, Korea, Russia, the US and Japan each account for approximately 10 percent of the total value, with 45 percent accounted for by the countries of the European Union. However, while the European states have not agreed how exactly the costs will be distributed among them. Because of this, the start of construction was postponed to April 2010. Despite another delay, scientists and officials involved in the creation of ITER say they will be able to complete the project by 2018.

The estimated thermonuclear power of ITER is 500 megawatts. Individual parts of the magnets reach a weight of 200 to 450 tons. To cool ITER, 33,000 cubic meters of water per day will be required.

In 1998, the US stopped funding its participation in the project. After the Republicans came to power in the country, and rolling blackouts began in California, the Bush administration announced an increase in energy investments. 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 announced that the US had changed its mind and intended to return to the project.

In terms of the number of participants, the project 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, it was decided to reduce the reactor power from 1.5 GW to 500 MW. Accordingly, the price of the project “lost weight”.

In June 2002, the symposium "ITER Days in Moscow" was held in the Russian capital. It discussed the theoretical, practical and organizational problems of the revival of the project, the success of which can change the fate of mankind and give it a new type of energy, in terms of efficiency and economy comparable only to solar energy.

In July 2010, representatives of the countries participating in the project of the international thermonuclear reactor ITER approved its budget and construction time at an extraordinary meeting held in Cadarache, France. .

At the last extraordinary meeting, the project participants approved the date for the start of the first experiments with plasma - 2019. Full trials are planned for March 2027, although project management has asked technical staff to try to optimize the process and start trials in 2026. The participants of the meeting also decided on the costs for the construction of the reactor, however, the amounts planned to be spent on the creation of the facility were not disclosed. According to information received by the editor of the ScienceNOW portal from an unnamed source, by the time the experiments begin, the cost of the ITER project may be 16 billion euros.

The meeting in Cadarache was also the first official working day for the project's new director, Japanese physicist Osamu Motojima. Before him, the project was led by the Japanese Kaname Ikeda since 2005, who wished to leave the post immediately after the approval of the budget and construction time.

The ITER fusion reactor is a joint project of the European Union, Switzerland, Japan, the USA, Russia, South Korea, China and India. The idea of ​​creating ITER has been considered since the 80s of the last century, however, due to financial and technical difficulties, the cost of the project is constantly growing, and the start date of construction is constantly being postponed. In 2009, experts expected that work on the creation of the reactor would begin in 2010. Later, this date was moved, and first 2018 and then 2019 were called as the launch time of the reactor.

Fusion reactions are fusion reactions of nuclei of light isotopes with the formation of 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 currently scientists are spending a lot more energy and money to start and maintain a fusion reaction.

Fusion is a cheap and environmentally friendly way to produce energy. For billions of years, uncontrolled thermonuclear fusion has been taking place on the Sun - helium is formed from the heavy isotope of hydrogen deuterium. This releases an enormous amount of energy. However, people on Earth have not yet learned to control such reactions.

Hydrogen isotopes will be used as fuel in the ITER reactor. During a thermonuclear reaction, energy is released when light atoms combine to form 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, hydrogen isotope atoms 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 moderated by a layer of dense matter (lithium).

Why did the creation of thermonuclear installations take so long?

Why is it that such important and valuable installations, the advantages of which have been discussed for almost half a century, have not yet been created? There are three main reasons (discussed below), the first of which can be called external or public, and the other two - internal, that is, due to the laws and conditions for the development of thermonuclear energy itself.

1. For a long time, it was believed that the problem of the practical use of fusion energy does 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 Fusion Energy at the US Department of Energy attempted to estimate the timing of R&D and the construction of a demonstration fusion power plant under different research funding options. At the same time, it turned out that the volume of annual funding for research in this direction is completely insufficient, and while maintaining the existing level of appropriations, the creation of thermonuclear installations will never be successful, since the allocated funds do not even correspond to the minimum, critical level.

2. A more serious obstacle to the development of research in this area is that a thermonuclear facility 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 the magnetic confinement of the plasma, but also its sufficient heating. The ratio of energy expended and received 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 ITER reactor mentioned above. The society was simply not ready to finance such large projects until there was sufficient confidence in success.

3. The development of thermonuclear energy has been very complex, however (despite insufficient funding and difficulties in choosing centers for the creation of JET and ITER facilities), there has been clear progress in recent years, although an operating 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 the reserves of fossil fuels may run out in the second half of this century. Moreover, the burning of fossil fuels may lead to the need to somehow capture and "store" the carbon dioxide released into the atmosphere (the CCS program mentioned above) in order to prevent serious changes in the planet's climate.

At present, almost all the energy consumed by mankind is created by burning fossil fuels, and the solution to the problem may be associated with the use of solar energy or nuclear energy (creation of fast breeder reactors, etc.). The global problem caused 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 attempts to develop alternative methods of energy generation should be encouraged.

As a matter of fact, we have a small choice of behavioral strategies and the development of thermonuclear energy is extremely important, even though there is no guarantee of success. The Financial Times (dated January 25, 2004) wrote about this:

Let's hope that there will be no major and unexpected surprises in the way of the development of thermonuclear energy. In this case, in about 30 years, we will be able to supply electric current from it to the energy networks for the first time, and in a little more than 10 years, the first commercial thermonuclear power plant will begin to operate. It is possible that in the second half of our century, nuclear fusion energy will begin to replace fossil fuels and gradually begin to play an increasingly important role in providing humanity with energy on a global scale.

There is no absolute guarantee that the task of creating thermonuclear energy (as an efficient and large-scale source of energy for all mankind) will be completed successfully, but the probability of success in this direction is quite high. Considering the huge potential of thermonuclear power plants, all the costs for projects of their rapid (and even accelerated) development can be considered justified, especially since these investments look very modest against the backdrop of a monstrous world energy market (4 trillion dollars a year8). Meeting the needs of mankind in energy is a very serious problem. As fossil fuels become less and less available (in addition, their use becomes undesirable), the situation is changing, and we simply cannot afford not to develop fusion power.

To the question "When will thermonuclear energy appear?" Lev Artsimovich (a recognized pioneer and leader of research in this area) once replied that "it will be created when it becomes really necessary for mankind"

ITER will be the first fusion reactor to generate more energy than it consumes. Scientists measure this characteristic with a simple factor they call "Q". If ITER makes it possible to achieve all the set scientific goals, then 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 is being finalized scientific research reached a Q value of almost 1. This means that it produced exactly the same amount of energy as it consumed. ITER will surpass this by demonstrating the creation of energy from fusion and achieving a Q value of 10. The idea is to generate 500 MW with an energy consumption of about 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 increased 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 been creating have been able to have 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 burning 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: turning on the engine for a short time and then turning it off is not the real operation of the car. Only when you drive your car for half an hour, it will enter a permanent mode of operation and demonstrate that such a car can really be driven.

That is, from a technical and scientific point of view, ITER will provide a Q value of 10 and an increased burning time.

The thermonuclear fusion program has a truly international, broad character. People are already counting on the success of ITER and are thinking about the next step - creating a prototype industrial thermonuclear reactor called DEMO. To build it, it is necessary that ITER work. We must achieve our scientific goals, because this will mean that the ideas we put forward are quite feasible. However, I agree that you should always think about what will happen next. In addition, during the operation of ITER 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 dispute about whether ITER should be exactly a tokamak. Some scholars put the question quite differently: should there be ITER? Experts in different countries, developing their own, not so large-scale thermonuclear projects, argue that such a large reactor is not needed at all.

However, their opinion is hardly worth considering authoritative. Physicists who have been working with toroidal traps for several decades have been involved in the creation of ITER. The design of the experimental thermonuclear reactor in Karadash was based on all the knowledge gained in the course of experiments on dozens of precursor tokamaks. And these results indicate that the reactor must have 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 of the tokamak-type reactors created to date, the large radius of the plasma torus is 2.96 meters. The power of the thermonuclear reaction already reaches more than 20 megawatts with a retention time of up to 10 seconds. The reactor returns about 40% of the energy invested in the plasma.

It is plasma physics that determines the energy balance,” Igor Semenov told Infox.ru. Associate professor at Moscow Institute of Physics and Technology described what an energy balance is with a simple example: “We all saw how a fire burns. In fact, there is not firewood burning, but gas. The energy chain there is as follows: gas burns, firewood heats up, firewood evaporates, gas burns again. Therefore, if we throw water into the fire, then we will sharply take energy from the system for the phase transition liquid water into a vapor state. The balance will become negative, the fire will go out. There is another way - we can simply take and spread the firebrands in space. The fire will also go out. The same is true for the fusion reactor we are building. The dimensions are chosen so as to create an appropriate positive energy balance for this reactor. Sufficient to build a real TNPP in the future, solving at this experimental stage all the problems that currently remain unresolved.”

The dimensions of the reactor once changed. 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 (at that time it was estimated at 10 billion US dollars) was too large. Physicists and engineers were required to reduce the cost of the installation. And this could be done only at the expense of size. The “redesign” of ITER was led by the French physicist Robert Aymar, who had previously worked on the French tokamak Tore Supra in Karadash. The outer radius of the plasma torus has been reduced from 8.2 meters to 6.3 meters. However, the risks associated with downsizing were partly offset by a few additional superconducting magnets, which made it possible to implement the then-discovered and explored plasma confinement regime.

source
http://ehorussia.com
http://oko-planet.su

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 a tremendous speed. The leading countries of the world have long thought about creating a new source of energy, environmentally friendly, safe from the point of view of operation, with colossal fuel reserves.

fusion reactor

Today there is a lot of talk about the use of so-called alternative forms of energy - renewable sources in the form of photovoltaics, wind power and hydropower. Obviously, due to their properties, these directions can only act as auxiliary sources of energy supply.

As a long-term perspective of mankind, only energy based on nuclear reactions can be considered.

On the one hand, an increasing number of 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 performance. 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 fusion (fusion) of light elements occur with the release of colossal energy.

Best of all, domestic specialists coped with the task of developing a facility for implementing nuclear fusion reactions in terrestrial conditions. 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 mankind - the International Experimental Thermonuclear Reactor (ITER, ITER), which is being built in Cadarache (France).

History of fusion

The first thermonuclear research began in countries working on their nuclear defense program. This is not surprising, because at the dawn of the atomic era main goal the emergence of deuterium plasma reactors was a study physical processes in hot plasma, the 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 was not without a funny 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 by a letter from a soldier Soviet army. In 1950, Sergeant Oleg Lavrentiev, who served on Sakhalin, sent to the Central Committee of the All-Union communist party a letter in which he proposed using lithium-6 deuteride in a hydrogen bomb instead of liquefied deuterium and tritium, and also creating a system with electrostatic hot plasma confinement for controlled thermonuclear fusion. The letter got to the response of the then young scientist Andrei Sakharov, who wrote in his response that he "considers it necessary to discuss Comrade Lavrentiev's project in detail."

Already by October 1950 Andrei Sakharov and his colleague Igor Tamm made the first estimates of the magnetic fusion reactor (MTR). The first toroidal facility 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, according to the combination of the initial syllables in the phrase "TOROIDAL CAMERA MAGNETIC COIL". In its classic form, a tokamak is a donut-shaped toroidal chamber placed in a toroidal magnetic field. From 1955 to 1966 8 such installations were built at the Kurchatov Institute, on which a lot of various studies were carried out. If until 1969, 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, and Egypt. In total, about 300 tokamaks have been built in the world so far, 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 United States - waged a tacit competition, who would be the first to be able to curb the plasma and actually start producing energy "from water".

The most important plus of a thermonuclear reactor is the reduction of radiation biological hazard by about a thousand times in comparison with all modern nuclear power reactors.

A thermonuclear reactor does not emit CO2 and does not generate "heavy" radioactive waste. This reactor can be placed anywhere, anywhere.

Half a century long step

In 1985, Academician Yevgeny Velikhov, on behalf of the USSR, suggested that scientists from Europe, the USA and Japan jointly create a thermonuclear reactor, and already in 1986 an agreement was reached in Geneva on the design of the facility, which later received the name ITER. In 1992, the partners signed a quadripartite agreement on the development of an engineering project for the reactor. The first phase 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 scheme repeats 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 at a power of thermonuclear reactions of 400–500 MW, at the second stage the mode of continuous operation of the reactor, as well as the tritium breeding system, will be tested.

The ITER reactor is not in vain called the energy future of mankind. Firstly, this is the world's largest scientific project, because almost the whole world is building it in France: the EU + Switzerland, China, India, Japan, South Korea, Russia and the USA are participating. The facility construction agreement was signed in 2006. European countries contribute about 50% of the project financing, Russia accounts for about 10% of the total, which will be invested in the form of high-tech equipment. But the most important contribution of Russia is the tokamak technology itself, which formed the basis of the ITER reactor.

Secondly, it 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 quite practical results, and by the end of the century the world expects the appearance of the first prototype of a commercial fusion power plant.

Scientists suggest that the first plasma at the international experimental thermonuclear reactor will be obtained in December 2025.

Why did literally the entire world scientific community begin to build such a reactor? The fact is that many of the 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 terms of science and technology, cannot have hundreds of technologies of the highest world level at once in all areas of technology used in such a high-tech and breakthrough project as a thermonuclear reactor. But ITER is hundreds of such 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 an agreement on who and what will supply the site, and that this should not be just 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 on your own.

Andrei Retinger, international journalist