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Physics
Atomic nuclei consist of two types of nucleons - protons and neutrons. They are held together by the so-called strong interaction. In this case, the binding energy of each nucleon with others depends on the total number of nucleons in the nucleus, as shown in the graph on the right. It can be seen from the graph that for light nuclei, with an increase in the number of nucleons, the binding energy increases, while for heavy nuclei it decreases. If nucleons are added to light nuclei or nucleons are removed from heavy atoms, then this difference in binding energy will stand out in the form kinetic energy particles released as a result of these actions. The kinetic energy (energy of motion) of particles is converted into thermal motion of atoms after the collision of particles with atoms. Thus, nuclear energy manifests itself in the form of heat.
A change in the composition of the nucleus is called nuclear transformation or nuclear reaction. A nuclear reaction with an increase in the number of nucleons in the nucleus is called a thermonuclear reaction or nuclear fusion. A nuclear reaction with a decrease in the number of nucleons in the nucleus is called nuclear decay or nuclear fission.
Nuclear fission
Nuclear fission can be spontaneous (spontaneous) and caused by external influences (induced).
Spontaneous division
Modern science believes that all chemical elements heavier than hydrogen were synthesized as a result of thermonuclear reactions inside stars. Depending on the number of protons and neutrons, the nucleus may be stable or show a tendency to spontaneous fission into several parts. After the end of the life of stars, stable atoms formed the world known to us, and unstable ones gradually decayed until the formation of stable ones. On Earth, only two such unstable ones have survived to this day in industrial quantities ( radioactive) chemical element - uranium and thorium. Other unstable elements are produced artificially in accelerators or reactors.
Chain reaction
Some heavy nuclei easily attach an external free neutron, become unstable and decay, emitting several new free neutrons. In turn, these released neutrons can fall into neighboring nuclei and also cause their decay with the release of next free neutrons. Such a process is called a chain reaction. In order for a chain reaction to occur, specific conditions must be created: a sufficiently large amount of a substance capable of a chain reaction must be concentrated in one place. The density and volume of this substance must be sufficient so that free neutrons do not have time to leave the substance, interacting with nuclei with a high probability. This probability is characterized neutron multiplication factor. When the volume, density and configuration of the substance allow the neutron multiplication factor to reach unity, then a self-sustaining chain reaction will begin, and the mass of the fissile substance will be called the critical mass. Naturally, each decay in this chain leads to the release of energy.
People have learned to chain reaction in special designs. Depending on the required rate of the chain reaction and its heat release, these designs are called nuclear weapons or nuclear reactors. In nuclear weapons, an avalanche-like uncontrolled chain reaction is carried out with the maximum achievable neutron multiplication factor in order to achieve maximum energy release before thermal destruction of the structure occurs. In nuclear reactors, they try to achieve a stable neutron flux and heat release so that the reactor performs its tasks and does not collapse from excessive heat loads. This process is called a controlled chain reaction.
controlled chain reaction
In nuclear reactors, conditions are created for controlled chain reaction. As is clear from the meaning of a chain reaction, its rate can be controlled by changing the neutron multiplication factor. To do this, you can change various design parameters: the density of the fissile material, the energy spectrum of neutrons, introduce neutron absorbing substances, add neutrons from external sources and so on.
However, the chain reaction is a very fast avalanche-like process, it is practically impossible to control it directly. Therefore, to control a chain reaction, delayed neutrons are of great importance - neutrons formed during the spontaneous decay of unstable isotopes formed as a result of the primary decays of fissile material. The time from primary decay to delayed neutrons varies from milliseconds to minutes, and the fraction of delayed neutrons in the neutron balance of the reactor reaches a few percent. Such time values already allow the process to be controlled by mechanical methods. The neutron multiplication factor, taking into account delayed neutrons, is called the effective neutron multiplication factor, and instead of the critical mass, the concept of reactivity of a nuclear reactor was introduced.
The dynamics of a controlled chain reaction is also affected by other fission products, some of which can effectively absorb neutrons (so-called neutron poisons). After the start of the chain reaction, they accumulate in the reactor, reducing the effective neutron multiplication factor and the reactivity of the reactor. After some time, the balance of accumulation and decay of such isotopes sets in, and the reactor enters a stable regime. If the reactor is shut down, then neutron poisons remain in the reactor for a long time, making it difficult to restart it. The characteristic lifetime of neutron poisons in the uranium decay chain is up to half a day. Neutron poisons prevent nuclear reactors from rapidly changing power.
Nuclear fusion
Neutron spectrum
The distribution of neutron energies in a neutron flux is usually called the neutron spectrum. The energy of a neutron determines the scheme of interaction between a neutron and a nucleus. It is customary to single out several ranges of neutron energies, of which the following are significant for nuclear technologies:
- Thermal neutrons. They are named so because they are in energy equilibrium with the thermal vibrations of atoms and do not transfer their energy to them during elastic interactions.
- resonant neutrons. They are named so because the cross section for the interaction of some isotopes with neutrons of these energies has pronounced irregularities.
- fast neutrons. Neutrons of these energies are usually produced as a result of nuclear reactions.
Prompt and delayed neutrons
A chain reaction is a very fast process. The lifetime of one generation of neutrons (that is, the average time from the appearance of a free neutron to its absorption by the next atom and the birth of the next free neutrons) is much less than a microsecond. Such neutrons are called prompt. In a chain reaction with a multiplication factor of 1.1, after 6 μs, the number of prompt neutrons and the released energy will increase by a factor of 1026. It is impossible to reliably manage such a fast process. Therefore, delayed neutrons are of great importance for a controlled chain reaction. Delayed neutrons arise from the spontaneous decay of fission fragments left after primary nuclear reactions.
Materials Science
isotopes
IN nature people usually encounter the properties of substances due to the structure of the electron shells of atoms. For example, it is the electron shells that are entirely responsible for Chemical properties atom. Therefore, before the nuclear era, science did not separate substances according to the mass of the nucleus, but only according to its electric charge. However, with the advent of nuclear technology, it became clear that all well-known simple chemical elements have many - sometimes dozens - varieties with different numbers of neutrons in the nucleus and, accordingly, completely different nuclear properties. These varieties became known as isotopes of chemical elements. Most naturally occurring chemical elements are mixtures of several different isotopes.
The vast majority of known isotopes are unstable and do not occur in nature. They are produced artificially for study or use in nuclear technologies. Separation mixtures isotopes of one chemical element, the artificial production of isotopes, the study of the properties of these isotopes - one of the main tasks of nuclear technology.
fissile materials
Some isotopes are unstable and decay. However, the decay does not occur immediately after the synthesis of the isotope, but after some time characteristic of this isotope, called the half-life. From the name it is obvious that this is the time during which half of the available nuclei of an unstable isotope decay.
In nature, unstable isotopes are almost never found, since even the longest-lived ones have completely decayed over the billions of years that have passed after the synthesis of the substances around us in the thermonuclear furnace of a long-extinct star. There are only three exceptions: these are two isotopes of uranium (uranium-235 and uranium-238) and one isotope of thorium - thorium-232. In addition to these, traces of other unstable isotopes can be found in nature, formed as a result of natural nuclear reactions: the decay of these three exceptions and the impact of cosmic rays on the upper atmosphere.
Unstable isotopes are the basis of virtually all nuclear technology.
Supporting the chain reaction
A group of unstable isotopes capable of maintaining a nuclear chain reaction, which is very important for nuclear technology, is singled out separately. To maintain a chain reaction, an isotope must absorb neutrons well, followed by decay, as a result of which several new free neutrons are formed. Mankind is incredibly lucky that among the unstable isotopes preserved in nature in industrial quantities, there was one that supports the chain reaction: uranium-235.
Construction materials
Story
Opening
At the beginning of the twentieth century, Rutherford made a huge contribution to the study of ionizing radiation and the structure of atoms. Ernest Walton and John Cockcroft were the first to split the nucleus of an atom.
Weapons nuclear programs
In the late 1930s, physicists realized the possibility of creating powerful weapons based on a nuclear chain reaction. This has led to a high state interest in nuclear technology. The first large-scale state atomic program appeared in Germany in 1939 (see German nuclear program). However, the war complicated the supply of the program, and after the defeat of Germany in 1945, the program was closed without significant results. In 1943, a large-scale program called the Manhattan Project began in the United States. In 1945, as part of this program, the world's first nuclear bomb was created and tested. Nuclear research in the USSR has been carried out since the 1920s. In 1940, the first Soviet theoretical design nuclear bomb is being worked out. Nuclear developments in the USSR have been secret since 1941. The first Soviet nuclear bomb was tested in 1949.
The main contribution to the energy release of the first nuclear weapons was made by the fission reaction. Nevertheless, the fusion reaction has been used as an additional source of neutrons to increase the amount of reacted fissile material. In 1952, in the USA and 1953 in the USSR, designs were tested in which most of the energy release was created by a fusion reaction. Such weapons were called thermonuclear. In a thermonuclear munition, the fission reaction serves to “ignite” a thermonuclear reaction without making a significant contribution to the overall energy of the weapon.
Nuclear energy
The first nuclear reactors were either experimental or weapons-grade, that is, designed to produce weapons-grade plutonium from uranium. The heat generated by them was dumped into environment. Low operating capacities and small temperature differences made it difficult to efficiently use such low-grade heat for the operation of traditional heat engines. In 1951, this heat was first used for power generation: in the USA, a steam turbine with an electric generator was installed in the cooling circuit of an experimental reactor. In 1954, the first nuclear power plant was built in the USSR, originally designed for the purposes of the electric power industry.
Technologies
Nuclear weapon
There are many ways to harm a person using nuclear technology. But only nuclear weapon explosive action based on a chain reaction. The principle of operation of such a weapon is simple: you need to maximize the neutron multiplication factor in a chain reaction so that as many nuclei as possible react and release energy before the design of the weapon is destroyed by the generated heat. To do this, one must either increase the mass of the fissile material or increase its density. Moreover, this must be done as quickly as possible, otherwise the slow growth of energy release will melt and evaporate the structure without an explosion. Accordingly, two approaches to the construction of a nuclear explosive device were developed:
- A scheme with an increase in mass, the so-called cannon scheme. Two subcritical pieces of fissile material were installed in the barrel of an artillery gun. One piece was fixed at the end of the barrel, the other acted as a projectile. The shot brought the pieces together, a chain reaction began and an explosive energy release occurred. Achievable approach speeds in such a scheme were limited to a couple of km / s.
- Scheme with increasing density, the so-called implosive scheme. Based on the peculiarities of metallurgy of the artificial plutonium isotope. Plutonium is able to form stable allotropic modifications that differ in density. The shock wave, passing through the volume of the metal, is able to transfer plutonium from an unstable low-density modification to a high-density one. This feature made it possible to transfer plutonium from a low-density subcritical state to a supercritical state with a propagation velocity shock wave in metal. To create a shock wave, conventional chemical explosives were used, placing them around the plutonium assembly so that the explosion compresses the spherical assembly from all sides.
Both schemes were created and tested almost simultaneously, but the implosive scheme turned out to be more efficient and more compact.
neutron sources
Another limiter to the energy release is the rate of increase in the number of neutrons in a chain reaction. In a subcritical fissile material, spontaneous decay of atoms takes place. The neutrons of these decays become the first in an avalanche-like chain reaction. However, for the maximum energy release, it is advantageous to first remove all neutrons from the substance, then transfer it to the supercritical state, and only then introduce the ignition neutrons into the substance in the maximum number. To achieve this, a fissile material is chosen with minimal contamination by free neutrons from spontaneous decays, and at the moment of transfer to the supercritical state, neutrons are added from external pulsed neutron sources.
Sources of additional neutrons are built on different physical principles. Initially, explosive sources based on the mixing of two substances became widespread. A radioactive isotope, usually polonium-210, was mixed with an isotope of beryllium. Alpha radiation from polonium caused a nuclear reaction of beryllium with the release of neutrons. Subsequently, they were replaced by sources based on miniature accelerators, on the targets of which a nuclear fusion reaction was carried out with a neutron yield.
In addition to the ignition sources of neutrons, it turned out to be advantageous to introduce additional sources into the circuit, triggered by the chain reaction that had begun. Such sources were built on the basis of reactions for the synthesis of light elements. Ampoules with substances of the deuteride lithium-6 type were installed in a cavity in the center of the plutonium nuclear assembly. Fluxes of neutrons and gamma rays from the developing chain reaction heated the ampoule to temperatures of thermonuclear fusion, and the explosion plasma compressed the ampoule, helping the temperature with pressure. A fusion reaction would begin, supplying additional neutrons for the fission chain reaction.
thermonuclear weapons
The neutron sources based on the fusion reaction were themselves a significant source of heat. However, the dimensions of the cavity in the center of the plutonium assembly could not contain much material for synthesis, and if placed outside the plutonium fissile core, it would not be possible to obtain the conditions required for synthesis in terms of temperature and pressure. It was necessary to surround the substance for synthesis with an additional shell, which, perceiving the energy of a nuclear explosion, would provide shock compression. They made a large ampoule of uranium-235 and installed it next to the nuclear charge. Powerful streams of neutrons from a chain reaction will cause an avalanche of fissions of the uranium atoms of the ampoule. Despite the subcritical design of the uranium ampoule, the total effect of gamma rays and neutrons from the chain reaction of the ignition nuclear explosion and the intrinsic fissions of the ampoule's nuclei will make it possible to create conditions for fusion inside the ampoule. Now the dimensions of the ampoule with the substance for synthesis turned out to be practically unlimited, and the contribution of the energy release from nuclear fusion many times exceeded the energy release of the ignition nuclear explosion. Such weapons became known as thermonuclear.
.Nuclear power plant
The heart of a nuclear power plant is a nuclear reactor - a device in which a controlled chain reaction of fission of heavy nuclei is carried out. The energy of nuclear reactions is released in the form of the kinetic energy of fission fragments and is converted into heat due to elastic collisions of these fragments with other atoms.
Fuel cycle
Only one natural isotope is known that is capable of a chain reaction - uranium-235. Its industrial reserves are small. Therefore, already today engineers are looking for ways to develop cheap artificial isotopes that support a chain reaction. The most promising plutonium is produced from the common isotope uranium-238 by neutron capture without fission. It is easy to produce it in the same power reactors as a by-product. Under certain conditions, a situation is possible when the production of artificial fissile material fully covers the needs of existing nuclear power plants. In this case, one speaks of a closed fuel cycle that does not require the supply of fissile material from a natural source.
Nuclear waste
Spent nuclear fuel (SNF) and construction materials reactors with induced radioactivity are powerful sources of dangerous ionizing radiation. Technologies for working with them are being intensively improved in the direction of minimizing the amount of disposed waste and reducing the period of their danger. SNF is also a source of valuable radioactive isotopes for industry and medicine. SNF reprocessing is a necessary stage in closing the fuel cycle.
Nuclear safety
Use in medicine
In medicine, various unstable elements are commonly used for research or therapy.
A.B. Koldobsky
Nuclear explosion - unique physical phenomenon, the only method mastered by mankind for the instantaneous release of colossal, truly cosmic amounts of energy in relation to the mass and volume of the device itself. It would be illogical to assume that such a phenomenon would go unnoticed by scientists and engineers.
The first scientific and technical publications on this problem appeared in the USA and the USSR in the mid-1950s. In 1957, the US Atomic Energy Commission adopted the Plowshare scientific and technical program for the peaceful use of nuclear explosive technologies (YaVT). The first peaceful nuclear explosion under this program - "Gnome", with a capacity of 3.4 kt, was carried out at the Nevada test site in 1961, and on January 15, 1965, an explosion to eject soil with a capacity of about 140 kt, carried out in the riverbed. Chagan on the territory of Semipalatinsk test site, opened the Soviet "Program N 7".
The last Soviet peaceful nuclear explosion "Rubin-1" was carried out in the Arkhangelsk region on September 6, 1988. During this time, 115 such explosions were carried out in the USSR (Russia - 81, Kazakhstan - 29, Uzbekistan and Ukraine - 2 each, Turkmenistan - 1 ). The average power of the devices used in this case was 14.3 kt, and without taking into account the two most powerful explosions (140 and 103 kt) - 12.5 kt.
Why, in fact, were peaceful nuclear explosions? For all the "exoticism" of this question, it has to be answered in essence, too stable in the views of both the broad masses of the population and many elite and intellectual circles remains the idea of them as almost amateur "amusements" of nuclear scientists - useless, but rather of everything, and very harmful to nature and society.
So, out of 115 peaceful nuclear explosions, 39 were carried out for the purpose of deep seismic sounding earth's crust to search for minerals, 25 - to intensify oil and gas fields, 22 - to create underground tanks for storing gas and condensate, 5 - to extinguish emergency gas fountains, 4 - to create artificial channels and reservoirs, 2 each - for crushing ore into quarry deposits, to create underground tanks - collectors for the removal of toxic waste chemical industries and for the construction of bulk dams, 1 - to prevent rock bursts and gas emissions in underground coal mines, 13 - to study the processes of self-burial of radioactive substances in the central zone of the explosion. The most significant customers were the USSR Mingeo (51 explosions), Mingazprom (26), Minnefteprom (13). Actually, by order of Minsredmash, 19 peaceful nuclear explosions were carried out.
Without discussing here the industrial and economic efficiency of explosions for various purposes (we will partially return to this below), we should draw an obvious conclusion based on what has been said: we are dealing with a technology that is certainly dangerous, but in many cases very effective, and sometimes, as we will see , which has no technical alternatives. That is why nuclear explosive technologies should be discussed precisely as such, but not at all as some attribute of Satan, as inalienable as a sulfur smell, a tail and a pitchfork.
As for the danger... There are no reliable data on damage to the life and health of at least one person as a result of an explosion, and a causal relationship between age-related deterioration in health and the fact of an explosion has not been reliably recorded for a single worker or resident. To speak in these conditions about the "special danger" of nuclear explosive technologies, knowing about Bhopal (1500 dead at once), Seveso and Minamata, about the terrible numbers of deaths in coal mines, car accidents, etc. somehow awkward. At the same time, the author does not at all want to appear as an opponent of the chemical industry or motor transport, he would only like to draw the reader's attention to the simple, but, alas, sometimes escaping the attention of "protectors of nature" fact that there are no safe technologies, that technological risk is an inevitable price. for the achieved level of civilizational development and that the complete rejection of this risk is tantamount to the rejection of the technology itself, which will immediately return humanity to skins, caves and stone axes. If, however, the “special danger” of nuclear explosive technologies, in the view of some media, is due only to the fact that they are nuclear explosive, then the conversation is transferred to another plane that lies beyond the scope of this article - there is little competence and real concern for the well-being of the external environment, but usually a lot of biased politics.
In essence, a reasonable discussion of all technologies should be conducted (if we keep in mind only the technical, economic and environmental aspects of the case) in the target quadrangle "effect-damage-cost-alternative". In the case of YAT, however, this is not enough, since the “quadrilateral” turns, figuratively speaking, into a “cube”, if we keep in mind the extraordinary significance of the political and, above all, legal aspects of the problem.
This means that, of course, it is pointless to discuss nuclear weapons, abstracting from the fact of the existence of the Comprehensive Nuclear-Test-Ban Treaty, paragraph 1 of Art. 1 of which expressly prohibits a state party (including Russia) from producing any nuclear weapons, regardless of their purpose and purpose. With this in mind, the author would like to quite unequivocally define his position: he does not in any way call for a revision of the Treaty, let alone its violation. The point in the approach he proposes is that, having unbiasedly and reasonably analyzed the possibilities of nuclear warfare, to answer the question of the expediency of their use in certain cases; namely, when such use from an economic, environmental, social point of view is objectively the best solution to some important problem and therefore has the right to count on international understanding and consent (of course, even hints of the possibility of obtaining any military benefits). And if the answer to the formulated question is positive in essence, then make efforts for the irreproachable legal registration of such a conclusion within the framework provided for this by the said Treaty - which is discussed below.
Returning to the discussion of nuclear warfare as such, we note that from the very beginning of the implementation of the "Program No. 7" it was based on the principle that a prerequisite for the use of nuclear weapons is either the absence of a "traditional" technology, or the economic and/or environmental inexpediency of its use. Subsequently, these requirements became even more stringent:
"1. Under no circumstances should nuclear explosions be even considered, in which measurable quantities of radioactive products can get into areas of the external environment accessible to humans. These are all types of so-called explosions of external action, entailing visible changes on the earth's surface - the construction of reservoirs ("Chagan"), canals (the object "Taiga", Perm region), bulk dams ("Crystal", Sakha-Yakutia) , failed funnels ("Galit", Kazakhstan). It should be taken into account that in these cases there is almost always a technological alternative (a dam, a canal or a reservoir can also be built using traditional methods).
"2. Nuclear explosions should not be used, as a result of which radioactive products, although they do not enter directly into the human environment (explosions internal action, or camouflage), but will be in contact with products used by humans (formation of gas and condensate storage facilities, ore crushing, intensification of oil and gas fields). Although there is often no technological alternative to such explosions, there is usually a targeted alternative (instead of intensifying depleted deposits, efforts can be focused on the exploration and development of new ones). In addition, practice has revealed undesirable radiation consequences: contamination of industrial sites during drilling (“puncture”) of such cavities, loss of their working volume and squeezing radioactive brines to the surface during the operation of gas storage facilities created in rock salt layers, etc.).
“3. Any nuclear camouflage explosions should be “frozen”, unless they are the only - quick and effective - solution commensurate with the scale of the problem (for example, emergency gas fountains).
The first quenching was performed at the Urta-Bulak gas field in Uzbekistan, where a gas reservoir with a pressure of over 300 atm was opened at a depth of 2450 m. On December 11, 1963, gas was released, an emergency fountain appeared with an average daily flow rate of 12 million m3 - this would be enough to supply a city like St. Petersburg. In addition to economic losses, the environmental damage was truly colossal - the gas contained a significant amount of highly toxic hydrogen sulfide, the long-term impact of which on wildlife could lead to unpredictable consequences, and the resulting fire added carbon oxides to this. The author, himself a participant in later works of this kind, will never forget the stinking hydrogen sulfide breath of an emergency gas fountain.
The attempts to cope with this disaster by traditional methods, which lasted for almost three years, were unsuccessful, during this time about 15.5 billion m3 of gas were lost. Atomic scientists got down to business. Under the leadership of the then Minister of the IMS, E.P. Slavsky, an original technique was developed to eliminate the release, based on drilling an inclined well from the Earth's surface to the trunk of an emergency well and detonating a special nuclear charge (with a capacity of 30 kt) at a depth of over 1500 m and at a distance of about 40 m from the trunk. The idea was that a huge - tens of thousands of atmospheres - pressure in the compression zone would cut the trunk of the emergency well, like with scissors.
After the explosion (September 30, 1966), the gas output from the emergency well stopped after 25 seconds (!). There was no release of radioactive products to the surface, just as there were no complications in the further exploitation of the deposit.
Four more emergency gas fountains were tamed in a similar way (in Uzbekistan, Turkmenistan, Ukraine and Russia). In this case, devices with a power of 4 to 47 kt were used, blown up at depths from 1510 to 2480 m. Neither early post-detonation nor late release of radioactive products to the earth's surface was observed. It should be noted that at two fields the use of traditional methods the elimination of the fountain was generally impossible, because. in the absence of a pronounced mouth of an emergency well, intensive pressure distribution of gas took place along the upper permeable geological horizons with the formation of gas gryphons over a large area (within a radius of up to a kilometer from the mouth).
Generation 3 reactors are called "advanced reactors". Three such reactors are already operating in Japan, large quantity is under development or construction. About twenty different types of reactors of this generation are under development. Most of them are "evolutionary" models, developed on the basis of second generation reactors, with changes made on the basis of innovative approaches. According to the World Nuclear Association, generation 3 is characterized by the following points: The standardized design of each type of reactor allows for faster licensing procedures, lower capital costs and construction time. Simplified and more robust design, making them easier to handle and less susceptible to operational failures. High availability and longer service life of approximately sixty years. Reducing the possibility of accidents with core meltdown Minimal impact on the environment. Deep burnup of fuel to reduce its consumption and the amount of production waste.
For more than 70 years, the nuclear industry has been working for the Motherland. And today the moment has come to realize that nuclear technologies are not only weapons and not only electricity, but new opportunities for solving a number of problems that concern humans.
Of course, the nuclear industry of our country was successfully built by a generation of victors - victors in the Great Patriotic War of 1941-1945. And now Rosatom reliably supports Russia's nuclear shield.
It is known that Igor Vasilyevich Kurchatov, at the first stage of the implementation of the domestic atomic project, while working on weapons developments, began to think about the widespread use of atomic energy for peaceful purposes. On the ground, underground, on the water, underwater, in the air and in space - nuclear and radiation technologies are now working everywhere. Today, specialists of the domestic nuclear industry continue to work and benefit the country, think about how to implement their new developments in modern conditions import substitution.
And it is important to talk about this - the peaceful direction of the work of domestic nuclear scientists, about which little is known.
Over the past decades, our physicists, our industry and our physicians have accumulated the necessary potential in order to make a breakthrough in the field of effective use nuclear technologies in the most important spheres of human life.
Technologies and developments created by our nuclear scientists are widely used in various fields and areas. This is medicine Agriculture, food industry. For example, to increase the yield, there is a special pre-sowing treatment of seeds, to increase the shelf life of wheat, grain processing technologies are used. All this is created by our specialists and based on domestic developments.
Or, for example, from abroad, from southern countries allspice and other spices are imported to us, products that are often susceptible to various infections. Nuclear technology makes it possible to destroy all such bacteria and food diseases. But unfortunately we don't use them.
Radiation therapy is considered one of the most effective in the treatment of cancer. But our scientists are constantly moving forward and the latest technologies have already been developed to increase the cure rate of patients. True, it is worth noting that, despite the availability of advanced technologies, such centers operate only in a few cities of the country.
It would seem that there is the potential of scientists, there are developments, but today the process of introducing unique nuclear technologies is still going quite slowly.
Previously, we were among those catching up, focusing primarily on Western countries bought isotopes and equipment from them. Over the past decade, the situation has changed dramatically. We already have sufficient capacity to implement these developments in life.
But if there are achievements on paper, what prevents us from putting them into practice today?
Here, perhaps, one can point to a complex bureaucratic mechanism for the implementation of such decisions. After all, in fact, now we are ready to provide a completely new qualitative format for the use of nuclear technologies in many areas. But, unfortunately, it happens very slowly.
It is safe to say that legislators, developers, representatives of regional and federal authorities are ready to work in this direction at their level. But in practice it turns out that there is no consensus, no common solution and programs for the introduction and implementation of nuclear technologies.
As an example, we can cite the city of Obninsk, the first science city, where a modern proton therapy center has recently started operating. The second one is in Moscow. But what about all of Russia? Here it is important to call on the regional authorities to actively join the dialogue between the developers and the federal center.
Again, we can state that the industry is developing, technologies are in demand, but so far there is not enough consolidation of efforts to implement these developments.
Our main task now is to bring together representatives of all levels of government, scientists, developers for a unified and productive dialogue. Obviously, there is a need to create modern nuclear technology centers in various industries, open a broad discussion and learn how to organize interdepartmental interaction for the benefit of our citizens.
Gennady Sklyar, member of the committee State Duma on energy.
Basic nuclear technologies Nuclear technologies are technologies based on the occurrence of nuclear reactions, as well as technologies aimed at changing the properties and processing of materials containing radioactive elements or elements on which nuclear reactions take place. energy technologies: -Technologies of nuclear reactors on thermal neutrons -Technologies of nuclear reactors on fast neutrons -Technologies of high- and ultrahigh-temperature nuclear reactors
Nuclear chemical technologies: - Technologies of nuclear raw materials and nuclear fuel - Technologies of materials of nuclear engineering Nuclear technologies of isotopic enrichment and production of monoisotopic and high-purity substances: - Gas diffusion technologies - Centrifuge technologies - Laser technologies Nuclear medical technologies
Growth in population and global energy consumption in the world, acute energy shortages that will only increase as depletion natural resources and outstripping growth of needs in it; tougher competition for limited and unevenly distributed fossil fuel resources; exacerbation of the complex environmental issues and increasing environmental restrictions; growing dependence on the unstable situation in the regions of the oil exporting countries and the progressive rise in prices for hydrocarbons; Forecasts in the field of future scenarios:
The growing difference in the level of energy consumption of the richest and poorest countries, the difference in the levels of energy consumption of different countries, creating the potential for social conflict; fierce competition between technology suppliers for nuclear power plants; the need to expand the areas of application of nuclear technologies and the large-scale energy-technological use of nuclear reactors for industrial areas of activity; the need for structural reforms and reforms in the harsh conditions of a market economy, etc. The provisions that are unshakable for making forecasts in the field of future scenarios:
Shares of countries in the world emission of CO 2 USA - 24.6% China - 13% Russia - 6.4% Japan - 5% India - 4% Germany - 3.8%. NPP with electric power 1 GW saves 7 million tons of CO 2 emissions per year compared to coal-fired CHP, 3.2 million tons of CO 2 emissions compared to gas-fired CHP.
Nuclear Evolution There are about 440 commercial nuclear reactors operating in the world. Most of them are in Europe and USA, Japan, Russia, South Korea, Canada, India, Ukraine and China. According to the IAEA, at least 60 more reactors will be put into operation within 15 years. Despite the variety of types and sizes, there are only four main categories of reactors: Generation 1 - reactors of this generation were developed in the 1950s and 1960s, and are modified and enlarged nuclear reactors for military purposes, designed for the movement of submarines or for the production plutonium. Generation 2 - this classification includes the vast majority of reactors in commercial operation. Generation 3 - reactors of this category are currently being commissioned in some countries, mainly in Japan. Generation 4 - this includes reactors that are under development and that are planned to be introduced in years.
Nuclear evolution Generation 3 reactors are called "advanced reactors". Three of these reactors are already in operation in Japan, with more under development or construction. About twenty different types of reactors of this generation are under development. Most of them are "evolutionary" models, developed on the basis of second generation reactors, with changes made on the basis of innovative approaches. According to the World Nuclear Association, generation 3 is characterized by the following points: The standardized design of each type of reactor allows for faster licensing procedures, lower capital costs and construction time. Simplified and more robust design, making them easier to handle and less susceptible to operational failures. High availability and longer service life of approximately sixty years. Reducing the possibility of accidents with core meltdown Minimal impact on the environment. Deep burnup of fuel to reduce its consumption and the amount of production waste. Generation 3
nuclear reactors Third Generation European Pressurized Water Reactor (EPR) The EPR is a model developed from the French N4 and the German KONVOI, second generation designs commissioned in France and Germany. Modular Bead Bed Reactor (PBMR) The PBMR is a High Temperature Gas Cooled Reactor (HTGR). Pressurized Water Reactor The following types of large reactor designs are available: APWR (designed by Mitsubishi and Westinghouse), APWR+ (Japanese Mitsubishi), EPR (French Framatome ANP), AP-1000 (US Westinghouse), KSNP+ and APR- 1400 (Korean companies) and CNP-1000 (China National Nuclear Corporation). In Russia, Atomenergoproekt and Gidropress have developed an improved VVER-1200.
Reactor Concepts Selected for Generation 4 GFR - Gas Cooled Fast Reactor LFR Lead Cooled Fast Reactor MSR - Molten Salt Reactor: Uranium fuel is melted in sodium fluoride salt circulating through the graphite channels of the core. The heat generated in the molten salt is removed to the secondary circuit Sodium-Cooled Fast Reactor VHTR – Ultra High Temperature Reactor: Reactor power 600 MW, helium-cooled core, graphite moderator. It is considered as the most promising and promising system aimed at generating hydrogen. Power generation at VHTR should become highly efficient.
Scientific research- the basis of the activity and development of the nuclear industry All practical activities of nuclear energy are based on the results of fundamental and applied research on the properties of matter Basic Research: fundamental properties and structure of matter, new sources of energy at the level of fundamental interactions Research and control of the properties of materials - Radiation materials science, creation of structural corrosion-resistant, heat-resistant, radiation-resistant steels, alloys and composite materials
Scientific research is the basis of activity and development of the nuclear industry Design, design, technologies. Creation of instruments, equipment, means of automation, diagnostics, control (general, secondary and precision engineering, instrumentation) Modeling of processes. Development mathematical models, calculation methods and algorithms. Development of parallel computing methods for neutron-physical, thermodynamic, mechanical, chemical and other computational studies using supercomputers
Nuclear power in the medium term Global nuclear power is expected to double by 2030 The expected increase in nuclear power can be achieved through further development of technologies for thermal neutron reactors and open nuclear fuel cycle The main problems of modern nuclear power are associated with the accumulation of SNF (this is not radioactive waste!) world of sensitive NFC and nuclear materials technologies
Tasks for creating a technological base for a large-scale nuclear power plant Development and implementation of fast breeder reactors in nuclear power plants Complete closure of the nuclear fuel cycle in nuclear power plants for all fissile materials Organization of a network of international nuclear fuel and energy centers to provide a range of services in the field of nuclear fuel cycle Development and implementation of reactors in nuclear power plants for industrial heat supply, hydrogen production, water desalination, etc.
PRODUCTION AND APPLICATION OF HYDROGEN When methane is oxidized on a nickel catalyst, the following main reactions are possible: CH 4 + H 2 O CO + ZH 2 - 206 kJ CH 4 + CO 2 2CO + 2H 2 - 248 kJ CH 4 + 0.5O 2 CO + 2H kJ CO + H 2 O CO 2 + N kJ High-temperature conversion is carried out in the absence of catalysts at temperatures °C and pressures up to 3035 kgf/cm 2, or 33.5 MN/m 2 ; in this case, almost complete oxidation of methane and other hydrocarbons with oxygen to CO and H 2 occurs. CO and H 2 are easily separated.
PRODUCTION AND APPLICATION OF HYDROGEN Recovery of iron from ore: 3CO + Fe 2 O 3 2Fe + 3CO 2 Hydrogen is able to reduce many metals from their oxides (such as iron (Fe), nickel (Ni), lead (Pb), tungsten (W) , copper (Cu), etc.). So, when heated to a temperature of ° C and above, iron (Fe) is reduced by hydrogen from any of its oxides, for example: Fe 2 O 3 + 3H 2 \u003d 2Fe + 3H 2 O
Conclusion Despite all its problems, Russia remains a great "nuclear" power, both in terms of military power and in terms of potential. economic development(nuclear technologies in the Russian economy). The nuclear shield is the guarantor of Russia's independent economic policy and stability throughout the world. The choice of the nuclear industry as the locomotive of the economy will first make it possible to bring mechanical engineering, instrumentation, automation and electronics, etc. to a decent level, during which there will be a natural transition from quantity to quality.
