Nuclear power plant - abstract. Nuclear power plant APP physics

A nuclear power plant is a complex of necessary systems, devices, equipment and structures intended for the production of electrical energy. The station uses uranium-235 as fuel. The presence of a nuclear reactor distinguishes nuclear power plants from other power plants.

At nuclear power plants there are three mutual transformations of energy forms

Nuclear power

goes into heat

Thermal energy

goes into mechanical

Mechanical energy

converted to electrical

1. Nuclear energy turns into thermal energy

The basis of the station is the reactor - a structurally allocated volume into which nuclear fuel is loaded and where a controlled chain reaction takes place. Uranium-235 is fissile by slow (thermal) neutrons. As a result, a huge amount of heat is released.

STEAM GENERATOR

2. Thermal energy turns into mechanical energy

Heat is removed from the reactor core by a coolant - a liquid or gaseous substance passing through its volume. This thermal energy is used to produce water vapor in a steam generator.

ELECTRIC GENERATOR

3. Mechanical energy is converted into electrical energy

The mechanical energy of the steam is directed to a turbogenerator, where it is converted into electrical energy and then passed through wires to consumers.

What does a nuclear power plant consist of?

A nuclear power plant is a complex of buildings housing technological equipment. The main building is the main building, where the reactor hall is located. It houses the reactor itself, a nuclear fuel holding pool, a reloading machine (for reloading fuel), all of which is monitored by operators from the control room (control room).

The main element of the reactor is the active zone (1). It is housed in a concrete shaft. Mandatory components of any reactor are a control and protection system that allows the selected mode of a controlled fission chain reaction to occur, as well as an emergency protection system to quickly stop the reaction in the event of an emergency. All this is mounted in the main building.

There is also a second building that houses the turbine hall (2): steam generators, the turbine itself. Next along the technological chain are capacitors and high-voltage power lines that go beyond the station site.

On the territory there is a building for reloading and storing spent nuclear fuel in special pools. In addition, the stations are equipped with elements of a recirculating cooling system - cooling towers (3) (a concrete tower tapering at the top), a cooling pond (a natural reservoir or an artificially created one) and spray pools.

What types of nuclear power plants are there?

Depending on the type of reactor, a nuclear power plant may have 1, 2 or 3 coolant circuits. In Russia, the most widespread are double-circuit nuclear power plants with reactors of the VVER type (water-cooled power reactor).

NPP WITH 1-CIRCUIT REACTORS

NPP WITH 1-CIRCUIT REACTORS

The single-circuit scheme is used at nuclear power plants with RBMK-1000 type reactors. The reactor operates in a block with two condensing turbines and two generators. In this case, the boiling reactor itself is a steam generator, which makes it possible to use a single-circuit circuit. The single-circuit circuit is relatively simple, but radioactivity in this case spreads to all elements of the unit, which complicates biological protection.

Currently, there are 4 nuclear power plants with single-circuit reactors operating in Russia

NPP WITH 2-CIRCUIT REACTORS

NPP WITH 2-CIRCUIT REACTORS

The double-circuit scheme is used at nuclear power plants with pressurized water reactors of the VVER type. Water is supplied under pressure into the reactor core and heated. The coolant energy is used in the steam generator to generate saturated steam. The second circuit is non-radioactive. The unit consists of one 1000 MW condensing turbine or two 500 MW turbines with associated generators.

Currently, there are 5 nuclear power plants with double-circuit reactors operating in Russia

NPP WITH 3-CIRCUIT REACTORS

NPP WITH 3-CIRCUIT REACTORS

The three-circuit scheme is used at nuclear power plants with fast neutron reactors with sodium coolant of the BN type. To prevent contact of radioactive sodium with water, a second circuit with non-radioactive sodium is constructed. Thus, the circuit turns out to be three-circuit.

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Nuclear power plants - (abstract)

Date added: March 2006

Nuclear power plants
INTRODUCTION

Past experience shows that at least 80 years pass before some main energy sources are replaced by others - wood is replaced by coal, coal is replaced by oil, oil is gas, chemical fuels are replaced by nuclear energy. The history of mastering atomic energy - from the first experimental experiments - dates back about 60 years, when in 1939. The fission reaction of uranium was discovered. In the 30s of our century, the famous scientist I.V. Kurchatov substantiated the need to develop scientific and practical work in the field of nuclear technology in the interests of the national economy of the country.

In 1946, the first nuclear reactor on the European-Asian continent was built and launched in Russia. A uranium mining industry is being created. The production of nuclear fuel - uranium-235 and plutonium-239 - was organized, and the production of radioactive isotopes was established. In 1954, the world's first nuclear power plant began operating in Obninsk, and 3 years later the world's first nuclear-powered ship, the icebreaker Lenin, entered the ocean. Since 1970, large-scale nuclear energy development programs have been implemented in many countries around the world. There are currently hundreds of nuclear reactors operating around the world.

FEATURES OF NUCLEAR ENERGY

Energy is the foundation. All the benefits of civilization, all material spheres of human activity - from washing clothes to exploring the Moon and Mars - require energy consumption. And the further, the more.

Today, atomic energy is widely used in many sectors of the economy. Powerful submarines and surface ships with nuclear power plants are being built. The peaceful atom is used to search for minerals. Radioactive isotopes have found widespread use in biology, agriculture, medicine, and space exploration.

There are 9 nuclear power plants (NPPs) in Russia, and almost all of them are located in the densely populated European part of the country. More than 4 million people live within the 30-kilometer zone of these nuclear power plants.

The positive significance of nuclear power plants in the energy balance is obvious. For its work, hydropower requires the creation of large reservoirs, under which large areas of fertile land along the banks of rivers are flooded. The water in them stagnates and loses its quality, which in turn aggravates the problems of water supply, fisheries and the leisure industry. Thermal power plants contribute to the greatest extent to the destruction of the biosphere and the natural environment of the Earth. They have already destroyed many tens of tons of organic fuel. To extract it, huge areas of land are taken from agriculture and other areas. In areas of open-pit coal mining, “lunar landscapes” are formed. And the increased ash content in fuel is the main reason for the release of tens of millions of tons into the air. All thermal power plants in the world emit up to 250 million tons of ash and about 60 million tons of sulfur dioxide into the atmosphere per year.

Nuclear power plants are the third “whale” in the modern world energy system. Nuclear power plant technology is undoubtedly a major achievement of scientific and technological progress. In case of trouble-free operation, nuclear power plants produce virtually no environmental pollution other than thermal pollution. True, as a result of the operation of nuclear power plants (and nuclear fuel cycle enterprises), radioactive waste is generated, which poses a potential danger. However, the volume of radioactive waste is very small, it is very compact, and it can be stored in conditions that guarantee that it will not leak out.

Nuclear power plants are more economical than conventional thermal stations, and, most importantly, if they are operated correctly, they are clean sources of energy.

At the same time, when developing nuclear energy in the interests of the economy, we must not forget about the safety and health of people, since mistakes can lead to catastrophic consequences.

In total, since the start of operation of nuclear power plants in 14 countries around the world, more than 150 incidents and accidents of varying degrees of complexity have occurred. The most typical of them: in 1957 - in Windscale (England), in 1959 - in Santa Susanna (USA), in 1961 - in Idaho Falls (USA), in 1979 - at the Tri nuclear power plant -Mile Island (USA), in 1986 - at the Chernobyl nuclear power plant (USSR).

NUCLEAR ENERGY RESOURCES

A natural and important question is the resources of the nuclear fuel itself. Are its reserves sufficient to ensure widespread development of nuclear energy? It is estimated that there are several million tons of uranium in mineable deposits around the globe. Generally speaking, this is not a small amount, but it must be taken into account that in the now widespread nuclear power plants with thermal neutron reactors, practically only a very small part of the uranium (about 1%) can be used to generate energy. Therefore, it turns out that when focusing only on thermal neutron reactors, nuclear energy in terms of resource ratio can not add much to conventional energy - only about 10%. There is no global solution to the looming problem of energy hunger. A completely different picture, different prospects appear in the case of the use of nuclear power plants with fast neutron reactors, which use almost all of the mined uranium. This means that the potential resources of nuclear energy with fast neutron reactors are approximately 10 times higher compared to traditional (fossil fuel) ones. Moreover, with the full use of uranium, its extraction becomes profitable even from deposits that are very poor in concentration, of which there are quite a few around the globe. And this ultimately means an almost unlimited (by modern standards) expansion of the potential raw material resources of nuclear energy.

So, the use of fast neutron reactors significantly expands the fuel base of nuclear energy. However, the question may arise: if fast neutron reactors are so good, if they are significantly superior to thermal neutron reactors in terms of uranium utilization efficiency, then why are the latter being built at all? Why not develop nuclear energy based on fast neutron reactors from the very beginning?

First of all, it should be said that at the first stage of the development of nuclear energy, when the total power of nuclear power plants was small and U 235 was enough, the issue of reproduction was not so pressing. Therefore, the main advantage of fast neutron reactors - a high breeding efficiency - was not yet decisive.

At the same time, at first fast neutron reactors were not yet ready for implementation. The fact is that, despite their apparent relative simplicity (no moderator), they are technically more complex than thermal neutron reactors. To create them, it was necessary to solve a number of new serious problems, which, naturally, required appropriate time. These tasks are mainly related to the peculiarities of the use of nuclear fuel, which, like the ability to reproduce, manifest themselves differently in different types of reactors. However, unlike the latter, these features have a more favorable effect in thermal neutron reactors.

The first of these features is that nuclear fuel cannot be completely consumed in the reactor, as conventional chemical fuel is consumed. The latter, as a rule, is burned in the firebox to the end. The possibility of a chemical reaction occurring practically does not depend on the amount of the reacting substance. A nuclear chain reaction cannot occur if the amount of fuel in the reactor is less than a certain value, called critical mass. Uranium (plutonium) in an amount constituting a critical mass is not a fuel in the proper sense of the word. It temporarily turns into some inert substance like iron or other structural materials found in the reactor. Only that part of the fuel that is loaded into the reactor in excess of the critical mass can burn out. Thus, nuclear fuel in an amount equal to the critical mass serves as a kind of catalyst for the process, ensuring the possibility of the reaction occurring without participating in it.

Naturally, fuel in an amount constituting a critical mass is physically inseparable in the reactor from the burnt-out fuel. The fuel elements loaded into the reactor contain fuel from the outset for both critical mass and burnup. The value of the critical mass varies for different reactors and is generally relatively large. Thus, for a serial domestic power unit with a thermal neutron reactor VVER-440 (water-cooled power reactor with a capacity of 440 MW), the critical mass of U 235 is 700 kg. This corresponds to an amount of coal of about 2 million tons. In other words, in relation to a coal-fired power plant of the same capacity, this seems to mean the obligatory presence of such a fairly significant emergency reserve of coal. Not a single kg of this reserve is consumed or can be consumed, but the power plant cannot operate without it.

The presence of such a large amount of “frozen” fuel, although it has a negative impact on economic indicators, is not too burdensome for thermal neutron reactors due to the actual cost ratio. In the case of fast neutron reactors, this has to be taken into account more seriously.

Fast neutron reactors have a significantly higher critical mass than thermal neutron reactors (for a given reactor size). This is explained by the fact that fast neutrons, when interacting with the environment, turn out to be more “inert” than thermal ones. In particular, the probability of causing fission of a fuel atom (per units of path length) for them is significantly (hundreds of times) less than for thermal ones. To ensure that fast neutrons do not fly outside the reactor without interaction and are not lost, their “inertness” must be compensated by increasing the amount of fuel added with a corresponding increase in the critical mass.

To ensure that fast neutron reactors do not lose out compared to thermal neutron reactors, it is necessary to increase the power developed for a given reactor size. Then the amount of “frozen” fuel per unit of power will decrease accordingly. Achieving a high heat release density in a fast neutron reactor was the main engineering task. Note that power itself is not directly related to the amount of fuel in the reactor. If this quantity exceeds the critical mass, then, due to the created nonstationarity of the chain reaction, any required power can be developed in it. The whole point is to ensure sufficiently intensive heat removal from the reactor. We are talking specifically about increasing the heat release density, because an increase, for example, in the size of the reactor, which contributes to an increase in heat removal, inevitably entails an increase in the critical mass, i.e., does not solve the problem.

The situation is complicated by the fact that such a familiar and well-developed coolant as ordinary water is not suitable for heat removal from a fast neutron reactor due to its nuclear properties. It is known to slow down neutrons and therefore lower the reproduction rate. Gas coolants (helium and others) have acceptable nuclear parameters in this case. However, the requirements for intensive heat removal lead to the need to use gas at high pressures (approximately 150 atm, or Pa), which causes its own technical difficulties. Molten sodium, which has excellent thermophysical and nuclear physical properties, was chosen as a coolant for heat removal from fast neutron reactors. It made it possible to solve the problem of achieving a high heat release density.

It should be pointed out that at one time the choice of “exotic” sodium seemed a very bold decision. There was no not only industrial, but also laboratory experience of its use as a coolant. There was concern about the high chemical activity of sodium when interacting with water, as well as with atmospheric oxygen, which, as it seemed, could manifest itself very unfavorably in emergency situations.

It was necessary to carry out a large complex of scientific and technical research and development, the construction of stands and special experimental fast neutron reactors in order to verify the good technological and operational properties of the sodium coolant. As was shown, the required high degree of safety is ensured by the following measures: firstly, careful manufacturing and quality control of all equipment that comes into contact with sodium; secondly, the creation of additional safety casings in case of emergency sodium leakage; thirdly, the use of sensitive leak indicators, which make it possible to quickly register the onset of an accident and take measures to limit and eliminate it. In addition to the mandatory existence of a critical mass, there is another characteristic feature of the use of nuclear fuel associated with the physical conditions under which it is located in the reactor. Under the influence of intense nuclear radiation, high temperature and, in particular, as a result of the accumulation of fission products, a gradual deterioration of the physical and mathematical, as well as nuclear physical properties of the fuel composition (a mixture of fuel and raw materials) occurs. Fuel that forms a critical mass becomes unsuitable for further use. It has to be periodically removed from the reactor and replaced with a fresh one. The extracted fuel must be regenerated to restore its original properties. In general, this is a labor-intensive, time-consuming and expensive process.

For thermal neutron reactors, the fuel content in the fuel composition is relatively small - only a few percent. For fast neutron reactors the corresponding fuel concentration is much higher. This is partly due to the already noted need to generally increase the amount of fuel in a fast neutron reactor in order to create a critical mass in a given volume. The main thing is that the probability ratio of causing fission of a fuel atom or being captured in a raw material atom is different for different neutrons. For fast neutrons it is several times less than for thermal ones, and, therefore, the fuel content in the fuel composition of fast neutron reactors should be correspondingly greater. Otherwise, too many neutrons will be absorbed by the atoms of the raw material and a stationary fission chain reaction in the fuel will be impossible.

Moreover, with the same accumulation of fission products in a fast neutron reactor, a fraction of the stored fuel will burn out several times less than in thermal neutron reactors. This will correspondingly lead to the need to increase the regeneration of nuclear fuel in fast neutron reactors. Economically, this will result in a noticeable loss.

But in addition to improving the reactor itself, scientists are constantly faced with questions about improving the safety system at nuclear power plants, as well as studying possible ways to process radioactive waste and convert them into safe substances. We are talking about methods of converting strontium and cesium, which have a long half-life, into harmless elements by bombarding them with neutrons or chemical methods. This is theoretically possible, but at the moment it is not economically feasible with modern technology. Although it may be that in the near future real results of these studies will be obtained, as a result of which nuclear energy will become not only the cheapest form of energy, but also truly environmentally friendly.

Impact of nuclear power plants on the environment

Technogenic impacts on the environment during the construction and operation of nuclear power plants are diverse. It is usually said that there are physical, chemical, radiation and other factors of the technogenic impact of the operation of nuclear power plants on environmental objects.

The most significant factors

local mechanical impact on the relief - during construction, damage to individuals in technological systems - during operation, runoff of surface and groundwater containing chemical and radioactive components,

changes in the nature of land use and metabolic processes in the immediate vicinity of the nuclear power plant,

changes in microclimatic characteristics of adjacent areas. The emergence of powerful heat sources in the form of cooling towers and cooling ponds during the operation of nuclear power plants usually noticeably changes the microclimatic characteristics of the surrounding areas. The movement of water in the external heat removal system, discharges of process water containing various chemical components have a traumatic effect on populations, flora and fauna of ecosystems.

Of particular importance is the distribution of radioactive substances in the surrounding space. Among the complex issues of environmental protection, the safety problems of nuclear power plants (NPPs) replacing thermal power plants using organic fossil fuels are of great public importance. It is generally accepted that nuclear power plants during their normal operation are much - no less than 5-10 times "cleaner" in environmental terms than coal-fired thermal power plants (TPPs). However, during accidents, nuclear power plants can have a significant radiation impact on people and ecosystems. Therefore, ensuring the safety of the ecosphere and protecting the environment from the harmful effects of nuclear power plants is a major scientific and technological task of nuclear energy, ensuring its future. Let us note the importance of not only the radiation factors of the possible harmful effects of nuclear power plants on ecosystems, but also thermal and chemical pollution of the environment, mechanical effects on the inhabitants of cooling ponds, changes in the hydrological characteristics of areas adjacent to nuclear power plants, i.e. the whole complex of technogenic impacts affecting the environmental well-being of the environment.

Emissions and discharges of harmful substances during NPP operation
Transfer of radioactivity in the environment

The initial events, which, developing over time, can ultimately lead to harmful effects on humans and the environment, are emissions and discharges of radioactivity and toxic substances from nuclear power plants. These emissions are divided into gas and aerosol emissions, emitted into the atmosphere through a pipe, and liquid discharges, in which harmful impurities are present in the form of solutions or fine mixtures that enter water bodies. Intermediate situations are also possible, as in some accidents, when hot water is released into the atmosphere and splits into steam and water.

Emissions can be either constant, under the control of operating personnel, or emergency, in bursts. Involved in the diverse movements of the atmosphere, surface and underground flows, radioactive and toxic substances spread in the environment, enter plants, animals and humans. The figure shows the air, surface and underground routes of migration of harmful substances in the environment. Secondary pathways that are less significant for us, such as wind transfer of dust and fumes, as well as the final consumers of harmful substances, are not shown in the figure.

Impact of radioactive emissions on the human body

Let's consider the mechanism of the effect of radiation on the human body: the ways in which various radioactive substances affect the body, their distribution in the body, deposition, impact on various organs and systems of the body and the consequences of this impact. There is a term “radiation entry gate”, which refers to the ways in which radioactive substances and isotope radiation enter the body.

Different radioactive substances penetrate the human body in different ways. It depends on the chemical properties of the radioactive element.

Types of radioactive radiation

Alpha particles are helium atoms without electrons, i.e. two protons and two neutrons. These particles are relatively large and heavy, and therefore brake easily. Their range in the air is of the order of several centimeters. When they stop, they release a large amount of energy per unit area, and therefore can cause great destruction. Due to the limited range, the source must be placed inside the body to receive the dose. Isotopes that emit alpha particles are, for example, uranium (235U and 238U) and plutonium (239Pu).

Beta particles are negatively or positively charged electrons (positively charged electrons are called positrons). Their range in the air is about several meters. Thin clothing can stop the flow of radiation, and to receive a dose of radiation, the radiation source must be placed inside the body, the isotopes emitting beta particles are tritium (3H) and strontium (90Sr). Gamma radiation is a type of electromagnetic radiation exactly like visible light. However, the energy of gamma particles is much greater than the energy of photons. These particles are highly penetrating, and gamma radiation is the only one of the three types of radiation that can irradiate the body externally. Two isotopes that emit gamma radiation are cesium (137Cs) and cobalt (60Co).

Paths of radiation penetration into the human body

Radioactive isotopes can enter the body through food or water. They spread throughout the body through the digestive organs. Radioactive particles from the air can enter the lungs during breathing. But they irradiate not only the lungs, but also spread throughout the body. Isotopes located in the ground or on its surface, emitting gamma radiation, are capable of irradiating the body from the outside. These isotopes are also transported by precipitation.

Limiting the hazardous impacts of nuclear power plants on ecosystems

The nuclear power plant and other industrial enterprises in the region have a variety of impacts on the totality of natural ecosystems that make up the ecosphere region of the nuclear power plant. Under the influence of these permanent or emergency impacts of AS and other technogenic loads, ecosystems evolve over time, changes in dynamic equilibrium states accumulate and are consolidated. People are absolutely not indifferent to which direction these changes in ecosystems are directed, how reversible they are, what the margins of stability are before significant disturbances. The regulation of anthropogenic loads on ecosystems is intended to prevent all unfavorable changes in them, and, in the best case, direct these changes in a favorable direction. In order to intelligently regulate the relationship of AS with the environment, it is necessary, of course, to know the reactions of biocenoses to the disturbing influences of AS. An approach to regulating anthropogenic impacts can be based on the ecological-toxicogenic concept, i.e. the need to prevent the “poisoning” of ecosystems with harmful substances and degradation due to excessive loads. In other words, it is impossible not only to poison ecosystems, but also to deprive them of the opportunity to develop freely, loading them with noise, dust, waste, limiting their habitats and food resources.

In order to avoid damage to ecosystems, certain maximum inputs of harmful substances into the organisms of individuals and other limits of influences that could cause unacceptable consequences at the population level must be determined and normatively fixed. In other words, the ecological capacities of ecosystems must be known, the values ​​of which should not be exceeded due to technogenic impacts. The ecological capacity of ecosystems for various harmful substances should be determined by the intensity of the supply of these substances, at which a critical situation will arise in at least one of the components of the biocenosis, i.e., when the accumulation of these substances approaches a dangerous limit, a critical concentration will be reached. In the values ​​of the maximum concentrations of toxicogens, including radionuclides, of course, cross-effects must also be taken into account. However, this apparently is not enough. To effectively protect the environment, it is necessary to legislatively introduce the principle of limiting harmful man-made impacts, in particular emissions and discharges of hazardous substances. By analogy with the principles of human radiation protection mentioned above, it can be said that the principles of environmental protection are that

Unreasonable technogenic impacts, accumulation of harmful substances in biocenoses must be excluded, technogenic loads on ecosystem elements must not exceed dangerous limits,

the entry of harmful substances into ecosystem elements and anthropogenic loads should be as low as possible, taking into account economic and social factors.

AS have thermal, radiation, chemical and mechanical effects on the environment. To ensure the safety of the biosphere, necessary and sufficient protective equipment is needed. By necessary environmental protection we mean a system of measures aimed at compensating for possible excesses of permissible values ​​of environmental temperatures, mechanical and dose loads, and concentrations of toxicogenic substances in the ecosphere. Sufficiency of protection is achieved when the temperatures in the media, dose and mechanical loads of the media, and the concentrations of harmful substances in the media do not exceed the limiting, critical values.

So, sanitary standards of maximum permissible concentrations (MAC), permissible temperatures, dose and mechanical loads should be a criterion for the need to take measures to protect the environment. A system of detailed standards on the limits of external exposure, limits on the content of radioisotopes and toxic substances in ecosystem components, and mechanical loads could normatively establish the limit of the limiting, critical impacts on ecosystem elements for their protection from degradation. In other words, the ecological capacities for all ecosystems in the region under consideration must be known for all types of impacts.

Various technogenic impacts on the environment are characterized by their frequency of repetition and intensity. For example, emissions of harmful substances have a certain constant component, corresponding to normal operation, and a random component, depending on the probability of accidents, i.e., on the safety level of the facility in question. It is clear that the more severe and dangerous the accident, the lower the likelihood of its occurrence. We now know from the bitter experience of Chernobyl that pine forests have a radiosensitivity similar to that characteristic of humans, and mixed forests and shrubs are 5 times less. Measures to prevent hazardous impacts, prevent them during operation, create opportunities for their compensation and manage harmful impacts should be taken at the design stage of facilities. This involves the development and creation of environmental monitoring systems for regions, the development of methods for calculating the forecasting of environmental damage, recognized methods for assessing the ecological capacities of ecosystems, and methods for comparing different types of damage. These measures should create the basis for active environmental management.

Destruction of hazardous waste

Particular attention should be paid to such activities as the accumulation, storage, transportation and disposal of toxic and radioactive waste.

Radioactive waste is not only a product of nuclear power plants, but also waste from the use of radionuclides in medicine, industry, agriculture and science. Collection, storage, disposal and disposal of waste containing radioactive substances are regulated by the following documents: SPORO-85 Sanitary rules for the management of radioactive waste. Moscow: Ministry of Health of the USSR, 1986; Rules and regulations on radiation safety in nuclear energy. Volume 1. Moscow: Ministry of Health of the USSR (290 pages), 1989; OSB 72/87 Basic sanitary rules.

For the neutralization and disposal of radioactive waste, the Radon system was developed, consisting of sixteen radioactive waste disposal sites. Guided by the Decree of the Government of the Russian Federation No. 1149-g dated 5.11.91. ,The Ministry of Atomic Industry of the Russian Federation, in cooperation with several interested ministries and institutions, has developed a draft state program for radioactive waste management with the aim of creating regional automated radioactive waste accounting systems, modernizing existing waste storage facilities and designing new radioactive waste disposal sites. The selection of land plots for storage, burial or destruction of waste is carried out by local governments in agreement with the territorial bodies of the Ministry of Natural Resources and the State Sanitary and Epidemiological Supervision.

The type of container for storing waste depends on its hazard class: from sealed steel cylinders for storing highly hazardous waste to paper bags for storing less hazardous waste. For each type of industrial waste storage facility (i.e., tailings and sludge storage facilities, industrial wastewater storage facilities, settling ponds, evaporation storage facilities), requirements have been determined for protection from contamination of soil, groundwater and surface water, for reducing the concentration of harmful substances in the air and the content of hazardous substances in storage tanks is within or below the maximum permissible concentration. The construction of new industrial waste storage facilities is permitted only if evidence is presented that it is not possible to switch to the use of low-waste or non-waste technologies or to use waste for any other purposes. Radioactive waste is buried in special landfills. Such landfills should be located at a great distance from populated areas and large bodies of water. A very important factor in protecting against the spread of radiation is the container that contains hazardous waste. Its depressurization or increased permeability can contribute to the negative impact of hazardous waste on ecosystems.

On standardization of environmental pollution levels

Russian legislation contains documents defining the duties and responsibilities of organizations for the safety and protection of the environment. Acts such as the Law on Environmental Protection, the Law on the Protection of Atmospheric Air, and the Rules for the Protection of Surface Water and Sewage Pollution play a certain role in preserving environmental values. However, in general, the effectiveness of environmental protection measures in the country, measures to prevent cases of high or even extremely high environmental pollution turns out to be very low. Natural ecosystems have a wide range of physical, chemical and biological mechanisms for neutralizing harmful and polluting substances. However, when the values ​​of critical intakes of such substances are exceeded, degradation phenomena may occur - weakened survival, decreased reproductive characteristics, decreased growth intensity, and motor activity of individuals. In the conditions of living nature, constant struggle for resources, such a loss of vitality of organisms threatens the loss of a weakened population, followed by a chain of losses of other interacting populations. Critical parameters of substances entering ecosystems are usually determined using the concept of ecological capacities. The ecological capacity of an ecosystem is the maximum capacity of the amount of pollutants entering the ecosystem per unit of time, which can be destroyed, transformed and removed from the ecosystem or deposited through various processes without significant disruption of the dynamic balance in the ecosystem. Typical processes that determine the intensity of “grinding” of harmful substances are the processes of transfer, microbiological oxidation and biosedimentation of pollutants. When determining the ecological capacity of ecosystems, both the individual carcinogenic and mutagenic effects of individual pollutants, as well as their enhancing effects due to their joint, combined action, must be taken into account.

What range of concentrations of harmful substances should be controlled? Let us give examples of maximum permissible concentrations of harmful substances, which will serve as guidelines in analyzing the possibilities of radiation monitoring of the environment. The main regulatory document on radiation safety, the Radiation Safety Standards (NRB-76/87), gives the values ​​of the maximum permissible concentrations of radioactive substances in water and air for professional workers and a limited part of the population. Data on some important, biologically active radionuclides are given in the table. Values ​​of permissible concentrations for radionuclides.

Nuclide, N
Half-life, T1/2 years
Yield from uranium fission, %
Allowable concentration, Ku/l
Permissible concentration
in the air
in the air
in air, Bq/m3
in water, Bq/kg
Tritium-3 (oxide)
12, 35
3*10-10
4*10-6
7, 6*103
3*104
Carbon-14
5730
1, 2*10-10
8, 2*10-7
2, 4*102
2, 2*103
Iron-55
2, 7
2, 9*10-11
7, 9*10-7
1, 8*102
3, 8*103
Cobalt-60
5, 27
3*10-13
3, 5*10-8
1, 4*101
3, 7*102
Krypton-85
10, 3
0, 293
3, 5*102
2, 2*103
Strontium-90
29, 12
5, 77
4*10-14
4*10-10
5, 7
4, 5*101
Iodine-129
1, 57*10+7
2, 7*10-14
1, 9*10-10
3, 7
1, 1*101
Iodine-131
8, 04 days
3, 1
1, 5*10-13
1*10-9
1, 8*101
5, 7*101
Cesium-135
2, 6*10+6
6, 4
1, 9*102
6, 3*102
Lead-210
22, 3
2*10-15
7, 7*10-11
1, 5*10-1
1, 8
Radium-226
1600
8, 5*10-16
5, 4*10-11
8, 6*10-3
4, 5
Uran-238
4, 47*10+9
2, 2*10-15
5, 9*10-10
2, 8*101
7, 3*10-1
Plutonium-239
2, 4*10+4
3*10-17
2, 2*10-9
9, 1*10-3
5

It can be seen that all environmental protection issues constitute a single scientific, organizational and technical complex, which should be called environmental safety. It should be emphasized that we are talking about the protection of ecosystems and people, as part of the ecosphere, from external man-made hazards, i.e. that ecosystems and people are the subject of protection. The definition of environmental safety can be the statement that environmental safety is the necessary and sufficient protection of ecosystems and humans from harmful technogenic influences

Environmental protection is usually distinguished as the protection of ecosystems from the impacts of nuclear power plants during their normal operation and safety as a system of protective measures in the event of accidents on them. As can be seen, with this definition of the concept of “security”, the range of possible impacts has been expanded, a framework has been introduced for necessary and sufficient security, which demarcates the areas of insignificant and significant, permissible and unacceptable impacts. Let us note that the basis of regulatory materials on radiation safety (RS) is the idea that the weakest link in the biosphere is man, who must be protected by all possible means. It is believed that if a person is properly protected from the harmful effects of nuclear radiation, then the environment will also be protected, since the radioresistance of ecosystem elements is usually significantly higher than that of humans. It is clear that this position is not absolutely indisputable, since biocenoses of ecosystems do not have the same capabilities that people have - to respond quickly and intelligently to radiation hazards. Therefore, for a person in current conditions, the main task is to do everything possible to restore the normal functioning of ecological systems and prevent violations of the ecological balance.

Latest publications
Secret mission of nuclear power plants. Announcement.

The North Caucasus Scientific Center for Higher Education and Rostov State University held the second scientific and practical conference “Problems of Nuclear Energy Development on the Don” on February 29–March 1. About 230 scientists from eleven cities of the Russian Federation took part in the conference, including from Moscow, St. Petersburg, Nizhny Novgorod, Novocherkassk, Volgodonsk, etc. The conference was attended by deputies of the Legislative Assembly of the Russian Federation, representatives of the regional Administration, the Ministry of Atomic Energy of the Russian Federation, the Rosenergoatom concern, the Rostov nuclear power plant, as well as environmental organizations and the region’s media. The conference took place in a business-like, constructive atmosphere. At the plenary meeting, the first deputy made an opening speech. Head of the Regional Administration I. A. Stanislavov. Presentations were made by Academician of the Russian Academy of Sciences V.I. Osipov, Director of Rostovenergo F.A. Kushnarev, Deputy. Director of the Rosenergoatom Concern A.K. Polushkin, Chairman of the South Russian Society “Human Health - 21st Century” V.I. Rusakov and others. More than 130 reports were presented in six sections in areas related to the construction and operation of a nuclear power plant.

At the final plenary meeting, the section leaders summed up the results, which in the very near future will be brought to the attention of the deputies of the Legislative Assembly and the public of the Don. All submitted materials will be published in a collection of reports.

Question: “To be or not to be Rostov Nuclear Power Plant? ” is especially acute now. Nuclear workers received the go-ahead for the RoNPP construction project. The public expert did not agree with the opinion of the state environmental assessment on the possibility of resuming construction.

Some residents of our region have the opinion that nuclear power plants “have no benefit but harm.” The Chernobyl syndrome makes it difficult to look at the state of affairs objectively. If we put aside emotions, we will find ourselves faced with very unpleasant facts. Already today, Rostov power engineers are talking about an impending energy crisis in the region. The equipment of fossil fuel power plants is not able to cope with increasing loads. In Western countries, which are now commonly referred to, 5-6 thousand kilowatt-hours are produced per capita per year. We currently have less than three. The prospect of being left with one thousand looms ahead. What does this mean? Just recently we were outraged by another sudden increase in electricity prices. And somehow the notorious “rolling” blackouts have already been forgotten. But all this is by no means a whim of energy specialists. This is our future life. Primorye is currently experiencing an energy crisis. People spent the winter in unheated apartments. Electricity is turned on once a day for a short time. Is it possible to imagine a normal life without electricity? What does it mean to leave a large industrial enterprise without electricity?

Alas, our life is firmly connected with sockets, wires, switches. Electricity generation is also PRODUCTION, requiring modern, strong capacities. Opponents of peaceful nuclear power propose to repurpose the RoNPP under construction to run on organic fuel. But the waste products of such plants are in no way inferior in terms of harmful effects on the environment, and in some indicators even exceed the impact of nuclear plants. In addition, the power of organic stations cannot be compared with the power of their atomic sisters.

There are proposals to transfer the Russian economy to harmless solar energy. This is of course good. But, alas, technological progress in the world has not advanced enough to seriously talk about the use of this type of energy. You can, of course, wait for the introduction of solar panels into the economy. Businesses are waiting, the entire economy will collapse, and you and I will have to burn fires to heat our homes and cook food.

Today, solar energy is more of a dream than a practical reality. In addition, nuclear power plants play an important role in the development of solar energy. It is at these stations that physical silicon is processed into amphora silicon. The latter is precisely the basis for the production of solar panels. In addition, at nuclear power plants, silicon single crystals are grown and then doped with radiation. The crystal is lowered into a nuclear reactor and, under the influence of radiation, turns into stable phosphorus. It is this phosphorus that is used to make night vision devices, various types of transistors, high-voltage devices and equipment.

Nuclear energy is a whole layer of knowledge-intensive production that can significantly improve the economic situation in the region.

The idea that the West is abandoning the construction of nuclear power plants is incorrect. Japan alone has 51 nuclear power units in operation and two new ones are under construction. Nuclear energy safety technologies have advanced so much that they make it possible to build stations even in seismically hazardous areas. Nuclear workers around the world, including our country, work under the motto: “Safety comes before the economy.” Most industrial facilities pose a potential danger to life. The recent tragedy in Central Europe, when the Danube River was poisoned with cyanide, has been compared in scale to the Chernobyl disaster. It was all the fault of the people who violated safety regulations. Yes, nuclear energy requires special treatment and special control. But this is not a reason to completely abandon it. It is dangerous to launch satellites into space, any of them can fall to Earth, it is dangerous to drive a car - thousands of people die in car accidents every year, it is dangerous to use gas, it is dangerous to fly on airplanes, it is harmful and dangerous to use computers. As the classic said: “Everything pleasant is either illegal, immoral, or leads to obesity.” But we launch satellites, drive cars, and cannot imagine our lives without natural gas and electricity. We are accustomed to a civilization that is currently impossible without the use of atomic energy. And this must be taken into account. “Newspaper Don”, No. 10(65), 07.03.2000

Elena Mokrikova
An emergency occurred at a nuclear power plant in Japan

In Japan, an emergency situation has once again developed at one of the nuclear power plants. This time, a water leak was recorded from the cooling system of a nuclear power plant located in the central part of the country, RBC reports. However, Japanese authorities stated that there is no threat of radioactive contamination of the environment. The cause of the leak has not yet been determined.

After the accident at the nuclear power plant in the city of Tokamura last year, the country's government recently decided to reduce the number of newly built nuclear reactors, reports the German agency Deutsche Presse Agentur. 22 people were exposed to radiation as a result of an accident at a South Korean nuclear power plant. 22 people were exposed to radiation as a result of an accident at a nuclear power plant in South Korea. As reported today, heavy water leaked during repairs to a cooling pump on Monday, Reuters reported, citing Yonhap news. According to Yonhap news agency, the accident at a nuclear power plant in the northern province of Kyongsang occurred on Monday at approximately 19.00.

According to Reuters, the leak was stopped. At this point, about 45 liters of heavy water had spilled into the external environment.

Let us recall that last Tuesday a similar accident occurred in Japan, where 55 people, mainly factory workers, were exposed to radioactive radiation. However, the South Korean authorities did not expect anything like this. The city answered “no”: 4,156 Volgodonsk residents spoke out against the nuclear power plant RoNPP: newspaper campaign “Let’s ask the city”

During the working week - from Monday to Friday - the newspapers "Evening Volgodonsk" and "Volgodonskaya Nedelya" held a joint campaign "Let's ask the city."

3,333 people took part in the “Evening Volgodonsk” survey. Most of them called by phone, some brought filled out coupons (send by mail - no envelopes or stamps). Others simply made and brought lists. The votes were distributed as follows: 55 people spoke in favor of the existence of RoNPP, 3278 were against.

899 Volgodonsk residents expressed their opinion to the Volgodonsk Week, 21 of whom voted for the nuclear power plant, 878 against it.

The survey showed that not all of our fellow citizens, due to economic difficulties, have lost their active life position and, as they say, have given up on everything. Many not only spoke out themselves, but also took the time to interview neighbors, relatives, and co-workers.

An extensive list of opponents of the nuclear power plant - 109 names - was transferred to the editorial office of VV on the last day of the action. Moreover, it was not possible to establish “authorship” - the collectors clearly worked not for fame, but for an idea. Another list, which had both pro and con opinions, also ended up without an “author.”

Another thing is lists from organizations. 29 employees of the Volgodonsk anti-tuberculosis dispensary spoke out against the construction of RoNPP. They were supported by 17 students of grade 11 "a" of school N10, led by their class teacher, and 54 HPV-16 workers.

Many people not only expressed their opinions, but also gave arguments for and against. Those who believe that the city needs a nuclear power plant see it, first of all, as a source of new jobs. Those who speak out against it believe that the most important thing is the environmental safety of the station, and in the absence of such safety, all other arguments are secondary.

“We survived Stalin’s genocide, then Hitler’s. A nuclear power plant on our land is nothing more than the same genocide, only more modern,” says Lidia Konstantinovna Ryabkina. Our rulers are restoring churches with one hand, and with the other they are killing us, their people, including through the construction of nuclear power plants in densely populated areas"

Among the survey participants there were also those who know about the possible consequences of living next to a “peaceful” atom not only from newspaper publications. Maria Alekseevna Yarema, who came to Volgodonsk from Ukraine, could not hold back her tears when talking about her relatives who remained there.

“After Chernobyl, all the relatives are very sick. The cemetery is growing by leaps and bounds. Mostly young people and children are dying. Nobody needs them there.” “Who will need us if, God forbid, something happens at the Rostov nuclear power plant?” asked the townspeople. Few people believe the assurances of nuclear scientists that nothing serious can happen. And, as you know, God protects those who are protected. Will it save us?

When it comes to covering RoNPP problems, opponents often accuse our newspaper of being biased and biased. But we just reflect public opinion on this issue. It, of course, cannot suit everyone. Nuclear workers, for example, or the city council, which said “yes” to the station a year ago. But it exists - and there is no escape from it.

Of course, a newspaper poll is not a referendum. But isn’t it cause for thought that of all those who took part in the survey, those who spoke in favor of the construction of RoNPP accounted for less than two percent of the total? Or did the NPP supporters not call us because they know the newspaper’s position and are not confident in its objectivity? But there is one caveat. To avoid mutual accusations of bias, we, by agreement with the RoAES information center, temporarily “exchanged” our telephone attendants (the information center, a few days after the start of the newspaper campaign, decided, in contrast, to hold its own). That is, their employee was on the editorial phone, ours was in the information center. A RoNPP employee got the opportunity to write down the opinions of townspeople with her own hands (in 20 minutes she had to do this eight times, all of them were against). Our duty officer spent an hour and a half in the information center in vain - during this time they did not call even once. And in the lists of those who called earlier, three names were lonely: two were “against”, one was “for”.

Anyone, including representatives of the authorities - both local and regional - can verify the authenticity of the statements of Volgodonsk residents personally. It is enough to contact any of the indicated addresses (all of them are in the editorial office). And here’s what is again unclear: on what basis does the myth grow again and again that the mood in the city has changed, that the majority of the population literally dreams of the speedy launch of a nuclear power plant? And this myth is persistently presented as reality and this is exactly how it is presented by individual city leaders to the Legislative Assembly and the regional administration.

“Let's ask the city,” said Don Governor Vladimir Chub. We asked. The city responded. Will this be followed by any conclusions from the Don authorities?

There is only one, perhaps not very simple and not the cheapest, but absolutely reliable way to find out the true state of affairs - a regional survey. And if our authorities are really interested in our opinion, then there is simply no other way to find out. But this is if they are interested. And if they don’t care about our opinion, then it’s time to stop being a hypocrite and say once and for all: the nuclear power plant will be launched, no matter what you think about it, even if you are in the majority three times over. Just don’t pretend that the city’s opinion coincides with the opinion of its elected leaders. RoNPP is their choice. There is nothing to add to this.

Conclusion
Ultimately, the following conclusions can be drawn:
Factors “Pro” of nuclear power plants:

Nuclear energy is by far the best form of energy production. Economical, high power, environmentally friendly when used correctly. Nuclear power plants, compared to traditional thermal power plants, have an advantage in fuel costs, which is especially evident in those regions where there are difficulties in providing fuel and energy resources, as well as a steady upward trend in the cost of fossil fuel production.

Nuclear power plants are also not prone to polluting the natural environment with ash, flue gases with CO2, NOx, SOx, and waste water containing petroleum products. Factors “against” nuclear power plants:

The terrible consequences of accidents at nuclear power plants.

Local mechanical impact on the terrain - during construction. Damage to individuals in technological systems - during operation. Runoff of surface and groundwater containing chemical and radioactive components.

Changes in the nature of land use and metabolic processes in the immediate vicinity of the nuclear power plant.

Changes in microclimatic characteristics of adjacent areas.

Nuclear power plant (NPP) is a complex of technical structures designed to generate electrical energy by using the energy released during a controlled nuclear reaction.

Uranium is used as a common fuel for nuclear power plants. The fission reaction is carried out in the main unit of a nuclear power plant - a nuclear reactor.

The reactor is mounted in a steel casing designed for high pressure - up to 1.6 x 107 Pa, or 160 atmospheres.
The main parts of VVER-1000 are:

1. The active zone, where nuclear fuel is located, a chain reaction of nuclear fission occurs and energy is released.
2. Neutron reflector surrounding the core.
3. Coolant.
4. Protection control system (CPS).
5. Radiation protection.

Heat in the reactor is released due to a chain reaction of fission of nuclear fuel under the influence of thermal neutrons. In this case, nuclear fission products are formed, among which there are both solids and gases - xenon, krypton. Fission products have very high radioactivity, so fuel (uranium dioxide pellets) is placed in sealed zirconium tubes - fuel rods (fuel elements). These tubes are combined in several pieces side by side into a single fuel assembly. To control and protect a nuclear reactor, control rods are used that can be moved along the entire height of the core. The rods are made of substances that strongly absorb neutrons - for example, boron or cadmium. When the rods are inserted deeply, a chain reaction becomes impossible, since neutrons are strongly absorbed and removed from the reaction zone. The rods are moved remotely from the control panel. With a slight movement of the rods, the chain process will either develop or fade. In this way the power of the reactor is regulated.

The station layout is double-circuit. The first, radioactive, circuit consists of one VVER 1000 reactor and four circulation cooling loops. The second circuit, non-radioactive, includes a steam generator and water supply unit and one turbine unit with a capacity of 1030 MW. The primary coolant is high-purity non-boiling water under a pressure of 16 MPa with the addition of a solution of boric acid, a strong neutron absorber, which is used to regulate the power of the reactor.

1. The main circulation pumps pump water through the reactor core, where it is heated to a temperature of 320 degrees due to the heat generated during the nuclear reaction.
2. The heated coolant gives up its heat to the secondary circuit water (working fluid), evaporating it in the steam generator.
3. The cooled coolant re-enters the reactor.
4. The steam generator produces saturated steam at a pressure of 6.4 MPa, which is supplied to the steam turbine.
5. The turbine drives the rotor of the electric generator.
6. The exhaust steam is condensed in the condenser and again supplied to the steam generator by the condensate pump. To maintain constant pressure in the circuit, a steam volume compensator is installed.
7. The heat of steam condensation is removed from the condenser by circulating water, which is supplied by the feed pump from the cooler pond.
8. Both the first and second circuits of the reactor are sealed. This ensures the safety of the reactor for personnel and the public.

If it is not possible to use a large amount of water for steam condensation, instead of using a reservoir, the water can be cooled in special cooling towers (cooling towers).

The safety and environmental friendliness of the reactor's operation are ensured by strict adherence to regulations (operating rules) and a large amount of control equipment. All of it is designed for thoughtful and efficient reactor control.
Emergency protection of a nuclear reactor is a set of devices designed to quickly stop a nuclear chain reaction in the reactor core.

Active emergency protection is automatically triggered when one of the parameters of a nuclear reactor reaches a value that could lead to an accident. Such parameters may include: temperature, pressure and coolant flow, level and speed of power increase.

The executive elements of emergency protection are, in most cases, rods with a substance that absorbs neutrons well (boron or cadmium). Sometimes, to shut down the reactor, a liquid absorber is injected into the coolant loop.

In addition to active protection, many modern designs also include elements of passive protection. For example, modern versions of VVER reactors include an “Emergency Core Cooling System” (ECCS) - special tanks with boric acid located above the reactor. In the event of a maximum design basis accident (rupture of the first cooling circuit of the reactor), the contents of these tanks end up inside the reactor core by gravity and the nuclear chain reaction is extinguished by a large amount of boron-containing substance, which absorbs neutrons well.

According to the “Nuclear Safety Rules for Reactor Facilities of Nuclear Power Plants”, at least one of the provided reactor shutdown systems must perform the function of emergency protection (EP). Emergency protection must have at least two independent groups of working elements. At the AZ signal, the AZ working parts must be activated from any working or intermediate positions.
The AZ equipment must consist of at least two independent sets.

Each set of AZ equipment must be designed in such a way that protection is provided in the range of changes in neutron flux density from 7% to 120% of the nominal:
1. By neutron flux density - no less than three independent channels;
2. According to the rate of increase in neutron flux density - no less than three independent channels.

Each set of emergency protection equipment must be designed in such a way that, over the entire range of changes in technological parameters established in the design of the reactor plant (RP), emergency protection is provided by at least three independent channels for each technological parameter for which protection is necessary.

Control commands of each set for AZ actuators must be transmitted through at least two channels. When one channel in one of the sets of AZ equipment is taken out of operation without taking this set out of operation, an alarm signal should be automatically generated for this channel.

Emergency protection must be triggered at least in the following cases:
1. Upon reaching the AZ setting for neutron flux density.
2. Upon reaching the AZ setting for the rate of increase in neutron flux density.
3. If the voltage disappears in any set of emergency protection equipment and the CPS power supply buses that have not been taken out of operation.
4. In case of failure of any two of the three protection channels for the neutron flux density or for the rate of increase of the neutron flux in any set of AZ equipment that has not been taken out of service.
5. When the AZ settings are reached by the technological parameters for which protection must be carried out.
6. When triggering the AZ from a key from a block control point (BCP) or a reserve control point (RCP).

The material was prepared by the online editors of www.rian.ru based on information from RIA Novosti and open sources

Nuclear power plants

General provisions. Nuclear power plants (NPPs) are essentially thermal power plants that harness the thermal energy of nuclear reactions.

The possibility of using nuclear fuel, mainly uranium 235 U, as a heat source is associated with the implementation of a chain reaction of fission of matter and the release of a huge amount of energy. A self-sustaining and controlled fission chain reaction of uranium nuclei is ensured in a nuclear reactor. Due to the efficiency of fission of uranium nuclei 235 U when bombarded with slow thermal neutrons, reactors using slow thermal neutrons still predominate. The uranium isotope 235 U is usually used as nuclear fuel; its content in natural uranium is 0.714%; The bulk of uranium is the isotope 238 U (99.28%). Nuclear fuel is usually used in solid form. It is enclosed in a protective shell. This kind of fuel elements are called fuel rods; they are installed in the working channels of the reactor core. The thermal energy released during the fission reaction is removed from the reactor core using coolant, which is pumped under pressure through each working channel or through the entire core. The most common coolant is water, which is thoroughly purified.

Water-cooled reactors can operate in water or steam mode. In the second case, steam is produced directly in the reactor core.

When uranium or plutonium nuclei fission, fast neutrons are produced, the energy of which is high. In natural or slightly enriched uranium, where the content of 235 U is low, a chain reaction with fast neutrons does not develop. Therefore, fast neutrons are slowed down to thermal (slow) neutrons. Substances that contain elements with low atomic mass and low absorption capacity for neutrons can be used as moderators. The main moderators are water, heavy water, and graphite.

Currently, thermal neutron reactors are the most developed. Such reactors are structurally simpler and easier to control compared to fast neutron reactors. However, a promising direction is the use of fast neutron reactors with expanded reproduction of nuclear fuel - plutonium; in this way most of the 238 U can be used.

The following main types of nuclear reactors are used at nuclear power plants in Russia:

RBMK(high power reactor, channel) – thermal neutron reactor, water-graphite;

VVER(water-cooled power reactor) – thermal neutron reactor, vessel type;

BN– fast neutron reactor with liquid metal sodium coolant.

The unit capacity of nuclear power units reached 1500 MW. Currently, it is believed that the unit power of a power unit NPP limited not so much by technical considerations as by safety conditions in case of reactor accidents.

Currently active NPP according to technological requirements, they operate mainly in the base part of the power system load schedule with a duration of use of the installed capacity of 6500 ... 7000 h/year

Nuclear power plant diagrams. Technology system NPP depends on the type of reactor, type of coolant and moderator, as well as on a number of other factors. The circuit can be single-circuit, double-circuit and three-circuit. Figure 1 shows as an example (1 – reactor; 2 – steam generator; 3 – turbine; 4 – transformer; 5 – generator; 6 – turbine condenser; 7 – condensate (feed) pump; 8 – main circulation pump.)

double-circuit circuit NPP for power plant with reactor type VVER. It can be seen that this diagram is close to the diagram KES, however, instead of a fossil fuel steam generator, a nuclear plant is used here.

Nuclear power plants are just like KES, are built according to the block principle in both the thermomechanical and electrical parts.

Nuclear fuel has a very high calorific value (1 kg of 235 U replaces 2,900 tons of coal), therefore NPP It is especially effective in areas poor in fuel resources, for example in the European part of Russia.

It is advantageous to equip nuclear power plants with high-power power units. Then in terms of their technical and economic indicators they are not inferior KES, and in some cases even surpass them. Currently, reactors with an electrical power of 440 and 1000 MW have been developed. VVER, as well as 1000 and 1500 MW types RBMK. In this case, the power unit is formed as follows: the reactor is combined with two turbine units (reactor VVER-440 and two 220 MW turbine units; reactor VVER-1000 and two 500 MW turbine units; reactor RBMK-1500 and two 750 MW turbine units) or with a turbine unit of the same power (a 1000 MW reactor and a 1000 MW unit power turbine unit).

Nuclear power plants with fast neutron reactors, which can be used to generate heat and electricity, as well as for the reproduction of nuclear fuel, are promising. Reactor type BN has an active zone (Figure 2, a),

Scheme of the reactor core

where a nuclear reaction occurs with the release of a flux of fast neutrons. These neutrons affect elements of 238 U, which is not usually used in nuclear reactions, and convert it into plutonium 239 Pu, which can later be used on NPP as nuclear fuel. The heat from the nuclear reaction is removed by liquid sodium and used to generate electricity.

Scheme NPP with reactor type BN(Figure 2, b-) Technology system - ( 1 – reactor; 2 – primary circuit heat exchanger; 3 – heat exchanger (drum) of the secondary circuit; 4 – steam turbine; 5 – step-up transformer; 6 – generator; 7 – capacitor; 8,9,10 – pumps)

three-circuit, two of them use liquid sodium (in the reactor circuit and the intermediate circuit). Liquid sodium reacts violently with water and steam. Therefore, in order to avoid contact of radioactive sodium of the primary circuit with water or water vapor in case of accidents, a second (intermediate) circuit is performed in which the coolant is non-radioactive sodium. The working fluid of the third circuit is water and water vapor.

Currently, a number of power units of the type are in operation BN, of which the largest BN-600.

Nuclear power plants have no flue gas emissions and no waste in the form of ash and slag. However, the specific heat release into the cooling water is NPP more than TES, due to higher specific steam consumption and, consequently, higher specific cooling water consumption. Therefore, on most new NPP It is planned to install cooling towers in which heat from the cooling water is removed to the atmosphere.

Feature NPP is the need for disposal of radioactive waste. This is done in special burial grounds, which exclude the possibility of radiation exposure to people.

To avoid exposure to possible radioactive emissions NPP on people in case of accidents, take special measures to increase the reliability of equipment (duplication of the safety system, etc.), and create a sanitary protection zone around the station.

The use of nuclear energy makes it possible to expand energy resources, thereby contributing to the conservation of fossil fuel resources, to reduce the cost of electrical energy, which is especially important for areas close to fuel sources, to reduce air pollution, to relieve transport involved in the transportation of fuel, to help supply electricity and heat to industries, using new technologies (for example, those involved in desalination of sea water and expansion of fresh water resources).

As for contamination, when using NPP the problem of lack of oxygen in the environment, which is typical for a thermal power plant due to its use for burning organic fuel, disappears. There is no emission of ash with flue gases. In connection with the problem of combating air pollution, it is important to note the feasibility of introducing nuclear power CHP, because CHP usually located near heat consumers, industrial hubs and large populated areas, where cleanliness of the environment is especially necessary.

When working NPP, do not consume fossil fuels (coal, oil, gas), and do not emit oxides of sulfur, nitrogen, or carbon dioxide into the atmosphere. This helps reduce the greenhouse effect leading to global climate change.

In many countries, nuclear power plants already generate more than half of the electricity (in France - about 75%, in Belgium - about 65%), in Russia only 15%.

Lessons from the Chernobyl accident NPP(in April 1986) demanded to significantly (many times) improve security NPP and forced to abandon construction NPP in densely populated and seismically active areas. Nevertheless, taking into account the environmental situation, nuclear energy should be considered promising.

In Russia on NPP About 120 billion kWh of electrical energy per year was consistently produced.

According to Rosenergoatom, further development of nuclear energy will be observed both in terms of power NPP, and in terms of the amount of electrical energy generated per NPP Russia.

Nuclear power plants General provisions. Nuclear power plants (NPPs) are essentially thermal power plants that harness the thermal energy of nuclear reactions.

Possibility of using nuclear fuel, mainly uranium 235U, in

Nuclear power plant Nuclear power plant (NPP)

- a set of technical structures designed to generate electrical energy by using the energy released during a controlled nuclear reaction.

In the second half of the 40s, even before the completion of work on the creation of the first atomic bomb (its test, as is known, took place on August 29, 1949), Soviet scientists began developing the first projects for the peaceful use of atomic energy, the general direction of which immediately became electric power industry.

In 1948, at the suggestion of I.V. Kurchatov and in accordance with the instructions of the party and government, the first work began on the practical use of atomic energy to generate electricity

The world's first nuclear power plant with a capacity of 5 MW was launched on June 27, 1954 in the USSR, in the city of Obninsk, located in the Kaluga region. In 1958, the 1st stage of the Siberian Nuclear Power Plant with a capacity of 100 MW was put into operation (total design capacity 600 MW). In the same year, the construction of the Beloyarsk industrial nuclear power plant began, and on April 26, 1964, the 1st stage generator supplied current to consumers. In September 1964, the 1st unit of the Novovoronezh NPP with a capacity of 210 MW was launched. The second unit with a capacity of 350 MW was launched in December 1969. In 1973, the Leningrad Nuclear Power Plant was launched.

Outside the USSR, the first industrial nuclear power plant with a capacity of 46 MW was put into operation in 1956 in Calder Hall (Great Britain). A year later, a nuclear power plant with a capacity of 60 MW came into operation in Shippingport (USA).

The world leaders in the production of nuclear electricity are: USA (788.6 billion kWh/year), France (426.8 billion kWh/year), Japan (273.8 billion kWh/year), Germany (158 .4 billion kWh/year) and Russia (154.7 billion kWh/year).

At the beginning of 2004, there were 441 nuclear power reactors operating in the world, and the Russian JSC TVEL supplies fuel for 75 of them.

The largest nuclear power plant in Europe is the Zaporozhye Nuclear Power Plant near the city of Energodar (Zaporozhye region, Ukraine), the construction of which began in 1980 and as of mid-2008 there are 6 nuclear reactors operating with a total capacity of 6 GigaWatt.

The largest nuclear power plant in the world, Kashiwazaki-Kariwa in terms of installed capacity (as of 2008), is located in the Japanese city of Kashiwazaki, Niigata Prefecture - there are five boiling water reactors (BWR) and two advanced boiling water reactors (ABWR) in operation, with a total capacity of 8,212 GigaWatts.

Classification

By reactor type

Nuclear power plants are classified according to the reactors installed on them:

Thermal neutron reactors, which use special moderators to increase the probability of neutron absorption by the nuclei of fuel atoms

Light water reactors

Heavy water reactors

Fast reactors

Subcritical reactors using external neutron sources

Fusion reactors

By type of energy released

Nuclear power plants can be divided into:

Nuclear power plants (NPPs) designed to generate only electricity

Nuclear combined heat and power plants (CHPs), generating both electricity and thermal energy

However, all nuclear power plants in Russia have heating plants designed to heat network water.

Operating principle

The figure shows a diagram of the operation of a nuclear power plant with a double-circuit pressurized water power reactor. The energy released in the reactor core is transferred to the primary coolant. Next, the coolant enters the heat exchanger (steam generator), where it heats the secondary circuit water to a boil. The resulting steam enters turbines that rotate electric generators. At the exit of the turbines, the steam enters the condenser, where it is cooled by a large amount of water coming from the reservoir.

The pressure compensator is a rather complex and cumbersome structure that serves to equalize pressure fluctuations in the circuit during reactor operation that arise due to thermal expansion of the coolant. The pressure in the 1st circuit can reach up to 160 atmospheres (VVER-1000).

In addition to water, molten sodium or gas can also be used as a coolant in various reactors. The use of sodium makes it possible to simplify the design of the reactor core shell (unlike the water circuit, the pressure in the sodium circuit does not exceed atmospheric pressure), and to get rid of the pressure compensator, but it creates its own difficulties associated with the increased chemical activity of this metal.

The total number of circuits may vary for different reactors, the diagram in the figure is shown for reactors of the VVER type (Water-Water Energy Reactor). Reactors of the RBMK type (High Power Channel Type Reactor) use one water circuit, and BN reactors (Fast Neutron Reactor) use two sodium and one water circuits.

If it is not possible to use a large amount of water for steam condensation, instead of using a reservoir, the water can be cooled in special cooling towers, which due to their size are usually the most visible part of a nuclear power plant.

Advantages and disadvantages

Advantages of nuclear power plants:

No harmful emissions;

Emissions of radioactive substances are several times less than coal electricity. stations of similar power (ash from coal thermal power plants contains a percentage of uranium and thorium sufficient for their profitable extraction);

Small volume of fuel used and the possibility of its reuse after processing;

High power: 1000-1600 MW per power unit;

Low cost of energy, especially thermal energy.

Disadvantages of nuclear power plants:

Irradiated fuel is dangerous and requires complex and expensive reprocessing and storage measures;

Variable power operation is not desirable for thermal neutron reactors;

The consequences of a possible incident are extremely severe, although its probability is quite low;

Large capital investments, both specific, per 1 MW of installed capacity for units with a capacity of less than 700-800 MW, and general, necessary for the construction of the station, its infrastructure, as well as in the event of possible liquidation.

Nuclear Power Plant Safety

The safety supervision of Russian nuclear power plants is carried out by Rostechnadzor.

Nuclear safety is regulated by the following documents:

General provisions for ensuring the safety of nuclear power plants. OPB-88/97 (PNAE G-01-011-97)

Rules for nuclear safety of reactor installations of nuclear power plants. PBYa RU AS-89 (PNAE G - 1 - 024 - 90)

Radiation safety is regulated by the following documents:

Sanitary rules for nuclear power plants. SP AS-99

Basic rules for ensuring radiation safety. OSPORB-02

Prospects

Despite these disadvantages, nuclear energy seems to be the most promising. Alternative methods of obtaining energy from the energy of tides, wind, sun, geothermal sources, etc. are currently characterized by a low level of energy produced and its low concentration. In addition, these types of energy production carry their own risks for the environment and tourism (“dirty” production of photovoltaic cells, the danger of wind farms for birds, and changes in wave dynamics.

Academician Anatoly Alexandrov: “Nuclear energy on a large scale will be the greatest benefit for humanity and will solve a number of pressing problems.”

Currently, international projects of new generation nuclear reactors are being developed, for example GT-MGR, which will improve safety and increase the efficiency of nuclear power plants.

Russia has begun construction of the world's first floating nuclear power plant, which will solve the problem of energy shortages in the country's remote coastal areas.[source?]

The USA and Japan are developing mini-nuclear power plants with a capacity of about 10-20 MW for the purpose of heat and electricity supply to individual industries, residential complexes, and in the future - individual houses. As the plant capacity decreases, the expected scale of production increases. Small-sized reactors (see, for example, Hyperion NPP) are created using safe technologies that greatly reduce the possibility of nuclear leakage.

Hydrogen production

The US government has adopted the Atomic Hydrogen Initiative. Work is underway (together with South Korea) to create a new generation of nuclear reactors capable of producing large quantities of hydrogen. INEEL (Idaho National Engineering Environmental Laboratory) predicts that one unit of the next generation nuclear power plant will produce hydrogen equivalent to 750,000 liters of gasoline daily.

Research into the feasibility of producing hydrogen at existing nuclear power plants is being funded.

Fusion energy

An even more interesting, although relatively distant, prospect is the use of nuclear fusion energy. Thermonuclear reactors, according to calculations, will consume less fuel per unit of energy, and both this fuel itself (deuterium, lithium, helium-3) and the products of their synthesis are non-radioactive and, therefore, environmentally safe.

Currently, with the participation of Russia, the construction of the international experimental thermonuclear reactor ITER is underway in the south of France.

Construction of nuclear power plants

Site selection

One of the main requirements when assessing the possibility of constructing a nuclear power plant is to ensure the safety of its operation for the surrounding population, which is regulated by radiation safety standards. One of the measures to protect the environment - the territory and the population from harmful effects during the operation of a nuclear power plant is the organization of a sanitary protection zone around it. When choosing a site for constructing a nuclear power plant, the possibility of creating a sanitary protection zone, defined by a circle, the center of which is the ventilation pipe of the nuclear power plant, should be taken into account. The population is prohibited from living in the sanitary protection zone. Particular attention should be paid to the study of wind conditions in the area of ​​nuclear power plant construction in order to locate the nuclear power plant downwind of populated areas. Based on the possibility of emergency leakage of active liquids, preference is given to sites with deep groundwater.

When choosing a site for the construction of a nuclear power plant, technical water supply is of great importance. The nuclear power plant is a major water user. The water consumption of nuclear power plants is negligible, but the water use is high, that is, the water is mainly returned to the water supply source. NPPs, as well as all industrial structures under construction, are subject to environmental protection requirements. When choosing a site for the construction of a nuclear power plant, one must be guided by the following requirements:

the lands allocated for the construction of nuclear power plants are unsuitable or of little use for agricultural production;

the construction site is located near reservoirs and rivers, in coastal areas not inundated by flood waters;

the soils of the site allow the construction of buildings and structures without additional expensive measures;

the groundwater level is below the depth of building basements and underground utilities and no additional costs are required for water reduction during the construction of a nuclear power plant;

the site has a relatively flat surface with a slope that provides surface drainage, while excavation work is kept to a minimum.

NPP construction sites, as a rule, are not allowed to be located:

in areas of active karst;

in areas of severe (massive) landslides and mudflows;

in areas of possible snow avalanches;

in swampy and waterlogged areas with a constant influx of pressure groundwater,

in areas of large failures as a result of mining;

in areas exposed to catastrophic phenomena such as tsunamis, etc.

in areas where mineral deposits occur;

To determine the feasibility of constructing nuclear power plants in the targeted areas and compare options based on geological, topographic and hydrometeorological conditions, at the site selection stage, specific surveys are carried out for each power plant location option under consideration.

Engineering-geological surveys are carried out in two stages. At the first stage, materials are collected from previously conducted surveys in the area under consideration and the degree of knowledge of the proposed construction site is determined. At the second stage, if necessary, special engineering-geological surveys are carried out with drilling wells and soil sampling, as well as reconnaissance geological survey of the site. Based on the results of desk processing of the collected data and additional surveys, an engineering-geological characteristic of the construction area should be obtained, defining:

relief and geomorphology of the territory;

stratigraphy, thickness and lithological composition of bedrock and Quaternary sediments distributed in the area to a depth of 50-100 m;

quantity, nature, location and distribution conditions of individual aquifers within the total depth;

the nature and intensity of physical and geological processes and phenomena.

When conducting engineering-geological surveys at the site selection stage, information is collected on the availability of local building materials - developed quarries and deposits of stone, sand, gravel and other building materials. During the same period, the possibilities of using groundwater for process and domestic drinking water supply are determined. When designing nuclear power plants, as well as other large industrial complexes, situational construction plans, master plan diagrams and master plans for the industrial site of the nuclear power plant are carried out.

Space-planning solutions for buildings

The goal of designing nuclear power plants is to create the most rational design. Basic requirements that NPP buildings must meet:

convenience for performing the main technological process for which they are intended (functional feasibility of the building);

reliability when exposed to the environment, strength and durability (technical feasibility of the building);

efficiency, but not at the expense of durability (economic feasibility).

aesthetics (architectural and artistic feasibility);

The layout of the nuclear power plant is created by a team of designers of different specialties.

Building structures of buildings and structures

A nuclear power plant includes buildings and structures for various purposes and, accordingly, of various designs. This is a multi-story and multi-span building of the main building with massive reinforced concrete structures enclosing the radioactive circuit; free-standing buildings of auxiliary systems, for example, chemical water treatment, diesel generator, nitrogen station, usually made in prefabricated reinforced concrete standard structures; underground channels and tunnels, pass-through and non-pass-through for placement of cable flows and communication pipelines between systems; aboveground overpasses connecting the main building and auxiliary buildings and structures, as well as administrative and sanitary buildings. The most complex and important building of a nuclear power plant is the main building, which is a system of structures formed in the general case by frame building structures and reactor compartment arrays.

Features of engineering equipment

A feature of nuclear power plants, like any building of nuclear installations, is the presence of ionizing radiation during operation. This main differentiating factor must be taken into account during design. The main source of radiation at nuclear power plants is a nuclear reactor, in which the fission reaction of fuel nuclei occurs. This reaction is accompanied by all known types of radiation.

Nuclear fuel cycle. Nuclear energy is a complex industry that includes many industrial processes that together form the fuel cycle. There are different types of fuel cycles, depending on the type of reactor and how the final stage of the cycle occurs.

Typically the fuel cycle consists of the following processes. Uranium ore is mined in the mines. The ore is crushed to separate uranium dioxide, and the radioactive waste goes into a dump. The resulting uranium oxide (yellow cake) is converted into uranium hexafluoride, a gaseous compound. To increase the concentration of uranium-235, uranium hexafluoride is enriched at isotope separation plants. The enriched uranium is then converted back into solid uranium dioxide, from which fuel pellets are made. Fuel elements (fuel elements) are collected from the pellets, which are combined into assemblies for insertion into the core of a nuclear reactor of a nuclear power plant. The spent fuel removed from the reactor has a high level of radiation and, after cooling on the territory of the power plant, is sent to a special storage facility. Provision is also made for the removal of low-level radiation waste accumulated during operation and maintenance of the plant. At the end of its service life, the reactor itself must be decommissioned (with decontamination and disposal of reactor components). Each stage of the fuel cycle is regulated to ensure the safety of people and the protection of the environment.

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