NPP reactor power. History and types of nuclear power plants. Disadvantages and advantages of nuclear power plants

How many of you have seen a nuclear power plant even from afar? Taking into account the fact that there are only ten operating nuclear power plants in Russia and they are protected, be healthy, I think the answer in most cases is negative. However, in LiveJournal, people, as you know, are experienced. Okay, but how many then saw the nuclear power plant from the inside? Well, for example, did you feel the vessel of a nuclear reactor with your own hand? Nobody. I guessed?

Well, today all subscribers of this photoblog have the opportunity to see all these high tech as close as possible. I understand that live it is much more interesting at times, but let's start small. In the future, perhaps, I will be able to take a few people with me, but for now we are studying the materiel!

02 . So, we are forty-five kilometers away from the construction site of the 4th stage of the Novovoronezh NPP. Not far from the operating nuclear power plant (the first power unit was launched back in the sixties of the last century), two modern power units with a total capacity of 2400 MW are being built. The construction is carried out according to the new AES-2006 project, which provides for the use of VVER-1200 reactors. But about the reactors themselves a little later.

03 . It is the fact that the construction is not yet completed that gives us a rare chance to see everything with our own eyes. Even the reactor hall, which in the future will be hermetically sealed and opened for maintenance only once a year.

04 . As you can see in the previous photo, the dome of the outer containment of the seventh power unit is still at the stage of concreting, but the reactor building of power unit No. 6 already looks more interesting (see photo below). In total, the concreting of this dome required more than 2,000 cubic meters of concrete. The diameter of the dome at the base is 44 m, the thickness is 1.2 m. Pay attention to the green pipes and the voluminous metal cylinder (weight - 180 tons, diameter - about 25 m, height - 13 m) - these are elements of the passive heat removal system (PHS). ). They are being installed at the Russian NPP for the first time. In the event of a complete blackout of all NPP systems (as happened at Fukushima), the PHRS is capable of providing long-term heat removal from the reactor core.

05 . Undoubtedly, the most large-scale element of nuclear power plants are tower cooling towers. In addition, it is one of the most efficient devices for cooling water in circulating water supply systems. The high tower creates the very draft of air that is necessary for the effective cooling of the circulating water. Thanks to the high tower, one part of the vapor is returned to the cycle, while the other is carried away by the wind.

06 . The height of the shell of the tower cooling tower of power unit No. 6 is 171 meters. It's about 60 floors. Now this building is the highest among similar ones ever built in Russia. Its predecessors did not exceed 150 m in height (at Kalinin NPP). It took more than 10 thousand cubic meters of concrete to build the structure.

07 . At the base of the cooling tower (diameter is 134 m) is the so-called pool bowl. Its upper part is "paved" with irrigation blocks. The fill is the main structural element of this type of cooling tower, designed to break up the flow of water flowing through it and provide it with a long time and maximum contact area with the cooling air. In essence, these are lattice modules made of modern polymeric materials.

08 . Naturally, I wanted to take an epic shot of the top, but the already mounted sprinkler prevented me from doing this. Therefore, we move to the cooling tower of power unit No. 7. Alas, it was frosty at night and we broke off with the elevator ride to the very top. He froze.

09 . Okay, maybe someday I'll have a chance to ride on such a top, but for now, a frame of an irrigation system being mounted.

10 . I thought about it ... Or maybe we were simply not allowed to go upstairs for security reasons?

11 . The entire territory of the construction site is full of warning, prohibiting and simply propaganda posters and signs.

12 . OK. We teleport to the building of the central control panel (CSC).
Well, of course, nowadays everything is controlled by computers.

13 . A huge room, flooded with light, is literally crammed with orderly rows of cabinets with automatic systems relay protection.

14 . Relay protection continuously monitors the state of all elements of the electric power system and reacts to the occurrence of damage and / or abnormal modes. In the event of damage, the protection system must identify a specific damaged area and turn it off by acting on special power switches designed to open fault currents (short circuit or earth fault).

15 . Fire extinguishers are placed along each wall. Automatic, of course.

16 . Next, we move to the building of a complete switchgear for 220 kV (KRUE-220). One of the most photogenic places in the entire nuclear power plant, in my opinion. There is also KRUE-500, but it was not shown to us. KRUE-220 is part of the general station electrical equipment and is designed to receive power from external power lines and distribute it at the site of the station under construction. That is, while the power units are being built, with the help of KRUE-220, the facilities under construction are directly supplied with electricity.

17 . In the AES-2006 project, according to which the sixth and seventh power units are being built, for the first time in the scheme of power distribution at distribution substations, packaged switchgears 220/500 kV of a closed type with SF6 insulation were used. Compared to open switchgears, which have been used in the nuclear power industry so far, the area of ​​closed switchgear is several times smaller. To understand the scale of the building, I recommend returning to the title photo.

18 . Naturally, after the new power units are put into operation, the KRUE-220 equipment will be used to transfer electricity generated at the Novovoronezh NPP to the Unified Energy System. Pay attention to the boxes near the power lines. Most electrical equipment used in construction is manufactured by Siemens.

19 . But not only. Here, for example, is a Hyundai autotransformer.
The weight of this unit is 350 tons, and it is designed to convert electricity from 500 kV to 220 kV.

20 . There are (which is nice) our solutions. Here, for example, is a step-up transformer manufactured by Elektrozavod OJSC. Established in 1928, the first domestic transformer plant played a colossal role in the industrialization of the country and in the development of domestic energy. Equipment with the brand name "Electrozavod" operates in more than 60 countries around the world.

21 . Just in case, I will explain a little about transformers. In general, the power distribution scheme (after completion of construction and commissioning, of course) provides for the production of electricity with a voltage of two classes - 220 kV and 500 kV. At the same time, the turbine (about it later) generates only 24 kV, which are fed through the conductor to the block transformer, where they rise to 500 kV. After that, a part of the power capacity is transferred through the KRUE-500 to the Unified Energy System. The other part goes to autotransformers (those same Hyundais), where it drops from 500 kV to 220 kV and also enters the power system through KRUE-220 (see above). So, as the mentioned block transformer, three single-phase step-up "electric factory" transformers are used (the power of each is 533 MW, the weight is 340 tons).

22 . If it is clear, let's move on to the steam turbine plant of power unit No. 6. Forgive me, my story seems to go from the end to the beginning (if we start from the process of generating electricity), but approximately in this sequence we walked around the construction site. So I beg your pardon.

23 . So, the turbine and generator are hidden under the casing. Therefore, I explain. Actually, a turbine is a unit in which the thermal energy of steam (with a temperature of about 300 degrees and a pressure of 6.8 MPa) is converted into mechanical energy rotation of the rotor, and already on the generator - into the electrical energy we need. The weight of the machine in the assembled state is more than 2600 tons, the length is 52 meters, it consists of more than 500 components. To transport this equipment to construction site about 200 trucks were involved. This K-1200–7-3000 turbine was manufactured at the Leningrad Metal Plant and is the first high-speed (3000 rpm) turbine with a capacity of 1200 MW in Russia. This innovative development was created specifically for nuclear power units of a new generation, which are being built according to the AES-2006 project. On the picture general form turbine shop. Or a turbine hall, if you like. The old-school nuclear scientists call the turbine a machine.

24 . One floor below are the turbine condensers. The capacitor group belongs to the main technological equipment engine room and, as everyone has already guessed, is designed to turn the steam exhausted in the turbine into liquid. The resulting condensate after the necessary regeneration is returned to the steam generator. The weight of the equipment of the condensing unit, which includes 4 condensers and a piping system, is more than 2000 tons. Inside the capacitors there are about 80,000 titanium tubes that form a heat transfer surface. with total area 100 thousand square meters.

25 . Got it? Here is the building of the turbine hall almost in section and we move on. At the very top of the overhead crane.

26 . We are moving to the block control panel of power unit No. 6.
The purpose, I think, is clear without explanation. Figuratively speaking, this is the brain of a nuclear power plant.

27 . BPU elements.

28 . And finally, we are going to see the premises of the reactor compartment! Actually, this is the place where the nuclear reactor, the primary circuit and their auxiliary equipment are located. Naturally, in the foreseeable future it will become airtight and inaccessible.

29 . And in the most natural way, when you get inside, the first thing you do is lift your head and marvel at the size of the containment dome. Well, a polar crane at the same time. A circular overhead crane (polar crane) with a lifting capacity of 360 tons is designed for the installation of large-sized and heavy containment equipment (reactor vessel, steam generators, pressure compensator, etc.). After the nuclear power plant is put into operation, the crane will be used for repair work and transportation of nuclear fuel.

30 . Further, of course, I rush to the reactor and watch its upper part in fascination, not yet suspecting that the situation is similar with icebergs. So that's what you are, reindeer. Figuratively speaking, this is the heart of a nuclear power plant.

31 . Reactor vessel flange. Later, an upper unit with CPS drives (reactor control and protection system) will be installed on it, which provides sealing of the main connector.

32 . Nearby we observe the pool of exposure. Its inner surface is a welded structure made of stainless steel sheet. It is designed for temporary storage of spent nuclear fuel unloaded from the reactor. After the residual heat release is reduced, the used fuel is transported from the spent fuel pool to the nuclear industry enterprise engaged in fuel reprocessing and regeneration (storage, disposal or reprocessing).

33 . And this is along the wall of the hydraulic tanks of the passive bay system of the core. They belong to passive safety systems, that is, they operate without the involvement of personnel and the use of external sources of energy supply. Simplifying, these are giant barrels filled with an aqueous solution of boric acid. In the event of an emergency, when the pressure in the primary circuit drops below a certain level, liquid is supplied to the reactor and the core is cooled. Thus, the nuclear reaction is quenched by a large amount of boron-containing water that absorbs neutrons. It should be noted that in the AES-2006 project, according to which the fourth stage of the Novovoronezh NPP is being built, for the first time an additional, second, stage of protection is provided - hydraulic reservoirs of the passive bay of the core (8 out of 12 reservoirs), each with a volume of 120 cubic meters.

34 . During future scheduled preventive maintenance and replacement of nuclear fuel, it will be possible to get inside the reactor compartment through the transport lock. It is a 14-meter cylindrical chamber with a diameter of more than 9 meters, hermetically locked on both sides with gate leaves that open alternately. The total weight of the lock is about 230 tons.

35 . From the outside of the lock, a panoramic view of the entire construction site as a whole and power unit No. 7 in particular opens up.

36 . Well, after taking a breath of fresh air, we go down below to see, in fact, the cylindrical reactor vessel. But so far we have come across only technological pipelines. The big green pipe is one of the loops, so we're pretty close now.

37 . And here he is. Pressurized pressurized pressurized water reactor VVER-1200. I will not delve into the jungle of nuclear fission and nuclear chain reaction (go ahead and already read diagonally), I will only add that inside the reactor there are many fuel elements (the so-called fuel rods) in the form of a set of sealed tubes made of special alloys with a diameter of 9.1 -13.5 mm and several meters long, filled with nuclear fuel pellets, as well as control rods that can be remotely moved from the control panel along the entire height of the core. These rods are made from substances that absorb neutrons, such as boron or cadmium. With the deep introduction of the rods, the chain reaction becomes impossible, since the neutrons are strongly absorbed and removed from the reaction zone. In this way, the power of the reactor is regulated. Now it is clear why there are so many holes in the upper part of the reactor?

38 . Yes, I almost forgot about the main circulation pump (MCP). It also belongs to the main technological equipment of the reactor building and is designed to create coolant circulation in the primary circuit. Within an hour, the unit pumps over 25 thousand cubic meters of water. The MCP also provides core cooling in all operating modes of the reactor plant. The installation includes four MCPs.

39 . Well, to consolidate the material covered, we look at the simplest scheme of the operation of a nuclear power plant. It's simple, isn't it? In especially neglected cases, re-read the post again, hehe))

40 . It's kind of like this in general. But for those who are close to the topic, I will throw in a few more cards with people. Agree, there are not so many of them in the report, and meanwhile, since 2006, many thousands of specialists of various profiles have worked here.

41 . Someone below...

42 . And someone at the top... Although you don't see them, they are there.

43 . And this is one of the most honored builders of the Novovoronezh NPP - a DEMAG crawler crane. It was he who lifted and installed these multi-ton elements of the reactor and engine rooms (load capacity - 1250 tons). Uncle-installer and a truck to understand the scale, and in full height (115 meters) look at the handsome man in photos 03 and 04.

And as a conclusion. Since March of this year, for reasons unknown to me, the operating Novovoronezh NPP and the Novovoronezh NPP-2 under construction have been merged. What we visited and what we used to call NVNPP-2 is now called the fourth stage of NVNPP, and the power units under construction have turned from the first and second into the sixth and seventh, respectively. Infa 110%. Those who wish can immediately go to rewrite articles on Wikipedia, and I thank the staff of the department for relations with NVNPP power units under construction and especially Tatyana, without whom this excursion would most likely not have taken place. Also, my thanks for the educational program on the construction of nuclear power plants to the shift supervisor Roman Vladimirovich Gridnev, as well as Vladimir

Nuclear energy is used in thermal power engineering, when energy is obtained from nuclear fuel in reactors in the form of heat. It is used to generate electrical energy V nuclear power plants (NPP), for power plants of large sea vessels, for desalination of sea water.

Nuclear energy owes its appearance, first of all, to the nature of the neutron discovered in 1932. Neutrons are part of all atomic nuclei, except for the hydrogen nucleus. Bound neutrons in the nucleus exist indefinitely. In their free form, they are short-lived, since they either decay with a half-life of 11.7 minutes, turning into a proton and emitting an electron and a neutrino, or are quickly captured by the nuclei of atoms.

Modern nuclear power is based on the use of energy released during the fission of a natural isotope uranium-235. At nuclear power plants, a controlled nuclear fission reaction is carried out in nuclear reactor. According to the energy of neutrons that produce nuclear fission, distinguish between thermal and fast neutron reactors.

The main unit of a nuclear power plant is a nuclear reactor, the diagram of which is shown in fig. 1. Energy is obtained from nuclear fuel, and then it is transferred to another working fluid (water, metallic or organic liquid, gas) in the form of heat; then it is converted into electricity in the same way as in conventional ones.

They control the process, maintain the reaction, stabilize the power, start and stop the reactor using special mobile control rods 6 And 7 from materials that intensively absorb thermal neutrons. They are driven by a control system 5 . Actions control rods are manifested in a change in the power of the neutron flux in the core. By channels 10 water circulates, cooling the biological protection concrete

The control rods are made of boron or cadmium, which are thermally, radiation and corrosion resistant, mechanically strong, and have good heat transfer properties.

Inside a massive steel case 3 there is a basket 8 with fuel elements 9 . The coolant enters through the pipeline 2 , passes through the core, washes all fuel elements, heats up and through the pipeline 4 enters the steam generator.

Rice. 1. Nuclear reactor

The reactor is placed inside a thick concrete biological containment device. 1 , which protects the surrounding space from the flow of neutrons, alpha, beta, gamma radiation.

Fuel elements (fuel rods) — main part reactor. A nuclear reaction directly takes place in them and heat is released, all other parts serve to insulate, control and remove heat. Structurally, fuel elements can be made of rod, plate, tubular, spherical, etc. Most often they are rod, up to 1 meter long, 10 mm in diameter. They are usually assembled from uranium pellets or from short tubes and plates. Outside, the fuel rods are covered with a corrosion-resistant, thin metal sheath. Zirconium, aluminum, magnesium alloys, as well as alloyed stainless steel are used for the shell.

The transfer of heat released during a nuclear reaction in the reactor core to the working fluid of the engine (turbine) of power plants is carried out according to single-loop, double-loop and three-loop schemes (Fig. 2).

Rice. 2. Nuclear power plant
a - according to a single-circuit scheme; b - according to the two-circuit scheme; c - according to the three-circuit scheme
1 - reactor; 2, 3 - biological protection; 4 - pressure regulator; 5 - turbine; 6 - electric generator; 7 - capacitor; 8 - pump; 9 - reserve capacity; 10 – regenerative heater; 11 – steam generator; 12 - pump; 13 - intermediate heat exchanger

Each circuit is a closed system. Reactor 1 (in all thermal circuits) placed inside the primary 2 and secondary 3 biological defenses. If the nuclear power plant is built according to a single-circuit thermal scheme, the steam from the reactor through the pressure regulator 4 enters the turbine 5 . The turbine shaft is connected to the generator shaft 6 , which produces electricity. The exhaust steam enters the condenser, where it is cooled and completely condensed. Pump 8 directs condensate to a regenerative heater 10 , and then it enters the reactor.

With a two-circuit scheme, the coolant heated in the reactor enters the steam generator 11 , where heat is transferred by surface heating to the coolant of the working fluid (feed water of the secondary circuit). In pressurized water reactors, the coolant in the steam generator is cooled by approximately 15 ... 40 ° C and then by a circulation pump 12 back to the reactor.

With a three-loop scheme, the coolant (usually liquid sodium) from the reactor is sent to an intermediate heat exchanger 13 and from there by the circulation pump 12 returns to the reactor. The coolant in the secondary circuit is also liquid sodium. This circuit is not irradiated and therefore non-radioactive. Sodium of the second circuit enters the steam generator 11 , gives off heat to the working fluid, and then the circulation pump is sent back to the intermediate heat exchanger.

The number of circulation circuits determines the type of reactor, the coolant used, its nuclear-physical properties, and the degree of radioactivity. The single-loop scheme can be used in boiling water reactors and in gas-cooled reactors. The most widespread double circuit when used as a heat carrier of water, gas and organic liquids. The three-circuit scheme is used at nuclear power plants with fast neutron reactors using liquid metal coolants (sodium, potassium, sodium-potassium alloys).

Nuclear fuel can be uranium-235, uranium-233 and plutonium-232. Raw materials for obtaining nuclear fuel - natural uranium and thorium. During the nuclear reaction of one gram of fissile material (uranium-235), energy equivalent to 22 × 10 3 kW × h (19 × 10 6 cal) is released. To obtain this amount of energy, it is necessary to burn 1900 kg of oil.

Uranium-235 is readily available, its energy reserves are about the same as organic fuel. However, using nuclear fuel with such low efficiency as it is now, the available uranium sources will be depleted in 50-100 years. At the same time, there are practically inexhaustible "deposits" of nuclear fuel - this is uranium dissolved in sea water. It is hundreds of times more abundant in the ocean than on land. The cost of obtaining one kilogram of uranium dioxide from sea water is about $60-80, and in the future it will drop to $30, while the cost of uranium dioxide produced in the richest deposits on land is $10-20. Therefore, after some time, the costs on land and "on sea water" will become of the same order.

The cost of nuclear fuel is about half that of fossil coals. At coal-fired power plants, 50-70% of the cost of electricity falls to the share of fuel, and at nuclear power plants - 15-30%. A modern thermal power plant with a capacity of 2.3 million kW (for example, Samara GRES) consumes about 18 tons of coal (6 trains) or 12 thousand tons of fuel oil (4 trains) daily. The nuclear one, of the same power, consumes only 11 kg of nuclear fuel during the day, and 4 tons during the year. However, a nuclear power plant is more expensive than a thermal one in terms of construction, operation, and repair. For example, the construction of a nuclear power plant with a capacity of 2–4 million kW costs approximately 50–100% more than a thermal one.

It is possible to reduce capital costs for NPP construction by:

1. standardization and unification of equipment;
2. development of compact reactor designs;
3. improvement of management and regulation systems;
4. reducing the duration of the shutdown of the reactor for refueling.

An important characteristic of nuclear power plants (nuclear reactor) is the efficiency of the fuel cycle. To improve the economy of the fuel cycle, you should:

• to increase the depth of nuclear fuel burnup;
• raise the breeding ratio of plutonium.

With each fission of the uranium-235 nucleus, 2-3 neutrons are released. Of these, only one is used for further reaction, the rest are lost. However, it is possible to use them for the reproduction of nuclear fuel by creating fast neutron reactors. When the reactor is operating on fast neutrons, it is possible to simultaneously obtain approximately 1.7 kg of plutonium-239 for 1 kg of burned uranium-235. In this way, the low thermal efficiency of nuclear power plants can be covered.

Fast neutron reactors are ten times more efficient (in terms of the use of nuclear fuel) than fuel neutron reactors. They have no moderator and use highly enriched nuclear fuel. Neutrons emitted from the core are absorbed not by structural materials, but by uranium-238 or thorium-232 located around.

In the future, the main fissile materials for nuclear power plants will be plutonium-239 and uranium-233, obtained respectively from uranium-238 and thorium-232 in fast neutron reactors. The conversion of uranium-238 into plutonium-239 in reactors will increase the resources of nuclear fuel by about 100 times, and thorium-232 into uranium-233 by 200 times.

On fig. Figure 3 shows a diagram of a fast neutron nuclear power plant.

Distinctive features of a nuclear power plant on fast neutrons are:

1. the change in the criticality of a nuclear reactor is carried out by reflecting part of the fission neutrons of nuclear fuel from the periphery back to the core using reflectors 3 ;
2. reflectors 3 can rotate, changing the leakage of neutrons and, consequently, the intensity of fission reactions;
3. reproduced nuclear fuel;
4. removal of excess thermal energy from the reactor is carried out using a cooler-radiator 6 .

Rice. 3. Scheme of a nuclear power plant on fast neutrons:
1 - fuel elements; 2 – renewable nuclear fuel; 3 – fast neutron reflectors; 4 - nuclear reactor; 5 - consumer of electricity; 6 - refrigerator-emitter; 7 - converter of thermal energy into electrical energy; 8 - radiation protection.

Converters of thermal energy into electrical energy

According to the principle of using thermal energy generated by a nuclear power plant, converters can be divided into 2 classes:

1. machine (dynamic);
2. machineless (direct converters).

In machine converters, the reactor is usually associated gas turbine plant, in which the working fluid can be hydrogen, helium, helium-xenon mixture. The efficiency of converting heat supplied directly to the turbogenerator into electricity is quite high - the efficiency of the converter η = 0,7-0,75.

A diagram of a nuclear power plant with a dynamic gas turbine (machine) converter is shown in fig. 4.

Another type of machine converter is a magnetogasdynamic or magnetohydrodynamic generator (MGDG). A diagram of such a generator is shown in fig. 5. The generator is a channel of rectangular cross section, two walls of which are made of a dielectric, and two of which are made of an electrically conductive material. An electrically conductive working fluid moves through the channels - liquid or gaseous, which is penetrated by a magnetic field. As you know, when a conductor moves in a magnetic field, an EMF arises, which along the electrodes 2 transferred to the consumer of electricity 3 . The energy source of the working heat flow is the heat released in the nuclear reactor. This thermal energy is spent on the movement of charges in a magnetic field, i.e. is converted into the kinetic energy of the current-carrying jet, and the kinetic energy is converted into electrical energy.

Rice. 4. Scheme of a nuclear power plant with a gas turbine converter:
1 - reactor; 2 – circuit with liquid metal coolant; 3 – heat exchanger for heat supply to gas; 4 - turbine; 5 - electric generator; 6 - compressor; 7 - radiator-radiator; 8 – heat removal circuit; 9 - circulation pump; 10 - heat exchanger for heat removal; 11 - heat exchanger-regenerator; 12 - circuit with the working fluid of the gas turbine converter.

Direct converters (machineless) of thermal energy into electrical energy are divided into:

1. thermoelectric;
2. thermionic;
3. electrochemical.

Thermoelectric generators (TEGs) are based on the Seebeck principle, which means that in a closed circuit consisting of dissimilar materials, a thermoelectric power arises if a temperature difference is maintained at the points of contact of these materials (Fig. 6). To generate electricity, it is advisable to use semiconductor TEGs, which have a higher efficiency, while the temperature of the hot junction must be brought up to 1400 K and higher.

Thermionic converters (TEC) make it possible to obtain electricity as a result of the emission of electrons from a cathode heated to high temperatures (Fig. 7).

Rice. 5. Magnetogasdynamic generator:
1 – magnetic field; 2 - electrodes; 3 - consumer of electricity; 4 - dielectric; 5 - conductor; 6 - working fluid (gas).

Rice. 6. Scheme of thermoelectric generator operation

Rice. 7. Scheme of operation of the thermionic converter

To maintain the emission current, heat is supplied to the cathode Q 1 . The electrons emitted by the cathode, having overcome the vacuum gap, reach the anode and are absorbed by it. During the "condensation" of electrons at the anode, energy is released equal to the work function of electrons with the opposite sign. If we ensure a continuous supply of heat to the cathode and its removal from the anode, then through the load R direct current will flow. Electron emission proceeds efficiently at cathode temperatures above 2200 K.

Safety and reliability of NPP operation

One of the main issues in the development of nuclear energy is to ensure the reliability and safety of nuclear power plants.

Radiation safety is ensured by:

1. the creation of reliable structures and devices for the biological protection of personnel from exposure to radiation;
2. purification of air and water leaving the NPP premises beyond its limits;
3. extraction and reliable localization of radioactive contamination;
4. daily dosimetric control of NPP premises and individual dosimetric control of personnel.

NPP premises, depending on the mode of operation and the equipment installed in them, are divided into 3 categories:

1. strict regime zone;
2. restricted zone;
3. normal mode zone.

Personnel are constantly in the rooms of the third category; these rooms at the station are radiation safe.

Nuclear power plants generate solid, liquid and gaseous radioactive waste. They must be disposed of in such a way that no pollution of the environment is created.

The gases removed from the room during ventilation may contain radioactive substances in the form of aerosols, radioactive dust and radioactive gases. The ventilation of the station is built in such a way that air flows pass from the most “clean” to “polluted”, and cross-flows in the opposite direction are excluded. In all rooms of the station, a complete replacement of air is carried out within no more than one hour.

During the operation of nuclear power plants, the problem of removal and disposal of radioactive waste arises. Fuel elements spent in reactors withstand a certain time in water pools directly at nuclear power plants until stabilization of isotopes with a short half-life occurs, after which the fuel elements are sent to special radiochemical plants for regeneration. There, nuclear fuel is extracted from the fuel rods, and radioactive waste is subject to burial.

Nuclear power is a modern and rapidly developing way of generating electricity. Do you know how nuclear power plants are arranged? What is the principle of operation of a nuclear power plant? What types nuclear reactors exist today? We will try to consider in detail the scheme of operation of a nuclear power plant, delve into the structure of a nuclear reactor and find out how safe the atomic method of generating electricity is.

How is a nuclear power plant organized?

Any station is a closed area far from the residential area. There are several buildings on its territory. The most important building is the reactor building, next to it is the turbine hall from which the reactor is controlled, and the safety building.

The scheme is impossible without a nuclear reactor. An atomic (nuclear) reactor is a device of a nuclear power plant, which is designed to organize a chain reaction of neutron fission with the obligatory release of energy in this process. But what is the principle of operation of a nuclear power plant?

The entire reactor plant is placed in the reactor building, a large concrete tower that hides the reactor and, in the event of an accident, will contain all the products of a nuclear reaction. This large tower is called containment, hermetic shell or containment.

The containment zone in the new reactors has 2 thick concrete walls - shells.
An 80 cm thick outer shell protects the containment area from external influences.

The inner shell with a thickness of 1 meter 20 cm has special steel cables in its device, which increase the strength of concrete by almost three times and will not allow the structure to crumble. On the inside, it is lined with a thin sheet of special steel, which is designed to serve as additional protection for the containment and, in the event of an accident, prevent the contents of the reactor from being released outside the containment area.

Such a device of a nuclear power plant can withstand the fall of an aircraft weighing up to 200 tons, an 8-magnitude earthquake, tornado and tsunami.

The first pressurized enclosure was built at the American nuclear power plant Connecticut Yankee in 1968.

The total height of the containment area is 50-60 meters.

What is a nuclear reactor made of?

To understand the principle of operation of a nuclear reactor, and hence the principle of operation of a nuclear power plant, you need to understand the components of the reactor.

• active zone. This is the area where the nuclear fuel (heat releaser) and the moderator are placed. Atoms of fuel (most often uranium is the fuel) perform a fission chain reaction. The moderator is designed to control the fission process, and allows you to carry out the reaction required in terms of speed and strength.
• Neutron reflector. The reflector surrounds the active zone. It consists of the same material as the moderator. In fact, this is a box, the main purpose of which is to prevent neutrons from leaving the core and getting into environment.
• Coolant. The coolant must absorb the heat that was released during the fission of fuel atoms and transfer it to other substances. The coolant largely determines how a nuclear power plant is designed. The most popular coolant today is water.
  Reactor control system. Sensors and mechanisms that bring the nuclear power plant reactor into action.

Fuel for nuclear power plants

What does a nuclear power plant do? Fuel for nuclear power plants are chemical elements with radioactive properties. At all nuclear power plants, uranium is such an element.

The design of the stations implies that nuclear power plants operate on complex composite fuel, and not on pure chemical element. And in order to extract uranium fuel from natural uranium, which is loaded into a nuclear reactor, you need to carry out a lot of manipulations.

Enriched uranium

Uranium consists of two isotopes, that is, it contains nuclei with different masses. They were named by the number of protons and neutrons isotope -235 and isotope-238. Researchers of the 20th century began to extract uranium 235 from the ore, because. it was easier to decompose and transform. It turned out that there is only 0.7% of such uranium in nature (the remaining percentages went to the 238th isotope).

What to do in this case? They decided to enrich uranium. Enrichment of uranium is a process when there are many necessary 235x isotopes and few unnecessary 238x isotopes left in it. The task of uranium enrichers is to make almost 100% uranium-235 from 0.7%.

Uranium can be enriched using two technologies - gas diffusion or gas centrifuge. For their use, uranium extracted from ore is converted into a gaseous state. In the form of gas, it is enriched.

uranium powder

Enriched uranium gas is converted into a solid state - uranium dioxide. This pure solid uranium 235 looks like large white crystals that are later crushed into uranium powder.

Uranium tablets

Uranium pellets are solid metal washers, a couple of centimeters long. In order to mold such tablets from uranium powder, it is mixed with a substance - a plasticizer, it improves the quality of tablet pressing.

Pressed washers are baked at a temperature of 1200 degrees Celsius for more than a day to give the tablets special strength and resistance to high temperatures. The way a nuclear power plant works directly depends on how well the uranium fuel is compressed and baked.

Tablets are baked in molybdenum boxes, because. only this metal is able not to melt at "hellish" temperatures over one and a half thousand degrees. After that, uranium fuel for nuclear power plants is considered ready.

What is TVEL and TVS?

The reactor core looks like a huge disk or pipe with holes in the walls (depending on the type of reactor), 5 times larger than a human body. These holes contain uranium fuel, the atoms of which carry out the desired reaction.

It’s impossible to simply throw fuel into a reactor, well, if you don’t want to get an explosion of the entire station and an accident with consequences for a couple of nearby states. Therefore, uranium fuel is placed in fuel rods, and then collected in fuel assemblies. What do these abbreviations mean?

• TVEL - fuel element (not to be confused with the same name Russian company that produces them). In fact, this is a thin and long zirconium tube made of zirconium alloys, into which uranium pellets are placed. It is in fuel rods that uranium atoms begin to interact with each other, releasing heat during the reaction.

Zirconium was chosen as a material for the production of fuel rods due to its refractoriness and anti-corrosion properties.

The type of fuel elements depends on the type and structure of the reactor. As a rule, the structure and purpose of fuel rods does not change; the length and width of the tube can be different.

The machine loads more than 200 uranium pellets into one zirconium tube. In total, about 10 million uranium pellets work simultaneously in the reactor.
FA - fuel assembly. NPP workers call fuel assemblies bundles.

In fact, these are several TVELs fastened together. Fuel assemblies are ready-made nuclear fuel, what a nuclear power plant runs on. It is fuel assemblies that are loaded into a nuclear reactor. About 150 - 400 fuel assemblies are placed in one reactor.
Depending on which reactor the fuel assembly will operate in, they come in different shapes. Sometimes the bundles are folded into a cubic, sometimes into a cylindrical, sometimes into a hexagonal shape.

One fuel assembly for 4 years of operation generates the same amount of energy as when burning 670 wagons of coal, 730 tanks with natural gas or 900 tanks loaded with oil.
Today, fuel assemblies are produced mainly at factories in Russia, France, the USA and Japan.

In order to deliver fuel for nuclear power plants to other countries, fuel assemblies are sealed in long and wide metal pipes, air is pumped out of the pipes and delivered on board cargo aircraft by special machines.

Nuclear fuel for nuclear power plants weighs prohibitively much, tk. uranium is one of the most heavy metals on the planet. His specific gravity 2.5 times more than steel.

Nuclear power plant: principle of operation

What is the principle of operation of a nuclear power plant? The principle of operation of nuclear power plants is based on a chain reaction of fission of atoms of a radioactive substance - uranium. This reaction takes place in the core of a nuclear reactor.

If you do not go into the intricacies of nuclear physics, the principle of operation of a nuclear power plant looks like this:
After the nuclear reactor is started, absorbing rods are removed from the fuel rods, which prevent the uranium from reacting.

As soon as the rods are removed, the uranium neutrons begin to interact with each other.

When neutrons collide, a mini-explosion occurs at the atomic level, energy is released and new neutrons are born, a chain reaction begins to occur. This process releases heat.

The heat is transferred to the coolant. Depending on the type of coolant, it turns into steam or gas, which rotates the turbine.

The turbine drives an electric generator. It is he who, in fact, generates electricity.

If you do not follow the process, uranium neutrons can collide with each other until the reactor is blown up and the entire nuclear power plant is blown to smithereens. Computer sensors control the process. They detect an increase in temperature or a change in pressure in the reactor and can automatically stop the reactions.

What is the difference between the principle of operation of nuclear power plants and thermal power plants (thermal power plants)?

Differences in work are only at the first stages. In nuclear power plants, the coolant receives heat from the fission of atoms of uranium fuel, in thermal power plants, the coolant receives heat from the combustion of organic fuel (coal, gas or oil). After either the atoms of uranium or the gas with coal have released heat, the schemes of operation of nuclear power plants and thermal power plants are the same.

Types of nuclear reactors

How a nuclear power plant works depends on how its nuclear reactor works. Today there are two main types of reactors, which are classified according to the spectrum of neurons:
A slow neutron reactor, also called a thermal reactor.

For its operation, 235 uranium is used, which goes through the stages of enrichment, the creation of uranium tablets, etc. Today, slow neutron reactors are in the vast majority.
Fast neutron reactor.

These reactors are the future, because they work on uranium-238, which is a dime a dozen in nature and it is not necessary to enrich this element. The disadvantage of such reactors is only in very high costs for design, construction and launch. Today, fast neutron reactors operate only in Russia.

The coolant in fast neutron reactors is mercury, gas, sodium or lead.

Slow neutron reactors, which are used today by all nuclear power plants in the world, also come in several types.

The IAEA organization (International Atomic Energy Agency) has created its own classification, which is used most often in the world nuclear industry. Since the principle of operation of a nuclear power plant largely depends on the choice of coolant and moderator, the IAEA has based its classification on these differences.

From a chemical point of view, deuterium oxide is an ideal moderator and coolant, because its atoms most effectively interact with the neutrons of uranium compared to other substances. Simply put, heavy water performs its task with minimal losses and maximum results. However, its production costs money, while it is much easier to use the usual “light” and familiar water for us.

A few facts about nuclear reactors...

It is interesting that one nuclear power plant reactor is built for at least 3 years!
To build a reactor, you need equipment that runs on an electric current of 210 kilo amperes, which is a million times the current that can kill a person.

One shell (structural element) of a nuclear reactor weighs 150 tons. There are 6 such elements in one reactor.

Pressurized water reactor

We have already found out how the nuclear power plant works in general, in order to “sort it out” let's see how the most popular pressurized nuclear reactor works.
All over the world today, generation 3+ pressurized water reactors are used. They are considered the most reliable and safe.

All pressurized water reactors in the world over all the years of their operation in total have already managed to gain more than 1000 years of trouble-free operation and have never given serious deviations.

The structure of nuclear power plants based on pressurized water reactors implies that distilled water circulates between the fuel rods, heated to 320 degrees. To prevent it from going into a vapor state, it is kept under a pressure of 160 atmospheres. The NPP scheme calls it primary water.

The heated water enters the steam generator and gives off its heat to the water of the secondary circuit, after which it “returns” to the reactor again. Outwardly, it looks like the pipes of the primary water circuit are in contact with other pipes - the water of the second circuit, they transfer heat to each other, but the waters do not contact. Tubes are in contact.

Thus, the possibility of radiation getting into the water of the secondary circuit, which will further participate in the process of generating electricity, is excluded.

Nuclear power plant safety

Having learned the principle of operation of nuclear power plants, we must understand how safety is arranged. The design of nuclear power plants today requires increased attention to safety rules.
The cost of nuclear power plant safety is approximately 40% of the total cost of the plant itself.

The NPP scheme includes 4 physical barriers that prevent the release of radioactive substances. What are these barriers supposed to do? At the right time, be able to stop the nuclear reaction, ensure constant heat removal from the core and the reactor itself, and prevent the release of radionuclides from the containment (containment zone).

• The first barrier is the strength of uranium pellets. It is important that they do not collapse under the influence of high temperatures in a nuclear reactor. In many ways, how a nuclear power plant works depends on how the uranium pellets were "baked" at the initial stage of production. If the uranium fuel pellets are baked incorrectly, the reactions of the uranium atoms in the reactor will be unpredictable.
• The second barrier is the tightness of fuel rods. Zirconium tubes must be tightly sealed, if the tightness is broken, then at best the reactor will be damaged and work stopped, at worst everything will fly into the air.
• The third barrier is a strong steel reactor vessel a, (that same large tower - a containment area) which "holds" all radioactive processes in itself. The hull is damaged - radiation will be released into the atmosphere.
• The fourth barrier is emergency protection rods. Above the active zone, rods with moderators are suspended on magnets, which can absorb all neutrons in 2 seconds and stop the chain reaction.

If, despite the construction of a nuclear power plant with many degrees of protection, it is not possible to cool the reactor core at the right time, and the fuel temperature rises to 2600 degrees, then the last hope of the safety system comes into play - the so-called melt trap.

The fact is that at such a temperature the bottom of the reactor vessel will melt, and all the remnants of nuclear fuel and molten structures will flow into a special “glass” suspended above the reactor core.

The melt trap is refrigerated and refractory. It is filled with the so-called "sacrificial material", which gradually stops the fission chain reaction.

Thus, the NPP scheme implies several degrees of protection, which almost completely exclude any possibility of an accident.

Which country had the world's first nuclear power plant? Who and how created the pioneer in the field of nuclear energy? How many nuclear power plants are there in the world? Which nuclear power plant is considered the largest and most powerful? Do you want to know? We'll tell you everything!

Prerequisites for the creation of the world's first nuclear power plant

The study of the reaction of atoms has been carried out since the beginning of the 20th century in all developed countries peace. The fact that people managed to subdue the energy of the atom was the first to be announced in the United States when, on August 6, 1945, they conducted tests by dropping an atomic bomb on the Japanese cities of Hiroshima and Nagasaki. In parallel, the use of the atom for peaceful purposes was studied. Developments of this kind were also in the USSR.

It was in the USSR that the world's first nuclear power plant appeared. The nuclear potential was used not for military, but for peaceful purposes.

Back in the 1940s, Kurchatov spoke of the need for a peaceful study of the atom in order to extract its energy for the benefit of people. But attempts to create nuclear energy were interrupted by Lavrenty Beria, in those years it was he who oversaw projects for the study of the atom. Beria believed that atomic energy could be the strongest weapon in the world, capable of making the USSR an invincible power. Well, in fact, he was not mistaken about the strongest weapon ...

After the explosions in Hiroshima and Nagasaka, the USSR began an intensive study of nuclear energy. Nuclear weapons at that moment were the guarantor of the country's security. After testing the Soviet nuclear weapons at the Semipalatinsk test site, in the USSR, the active development of nuclear energy began. Nuclear weapons had already been created and tested, it was possible to focus on the use of the atom for peaceful purposes.

How was the world's first nuclear power plant built?

For the atomic project of the USSR in 1945-1946, 4 nuclear power laboratories were created. The first and fourth in Sukhumi, the second - in Snezhinsk and the third near the Obninskaya station in the Kaluga region, it was called laboratory V. Today it is the Institute of Physics and Power Engineering. Leiputsky.

The world's first nuclear power plant was called Obninsk.

It was created with the participation of German physicists, who, after the end of the war, were voluntarily - forcibly discharged from Germany to work in the atomic laboratories of the Union, the same was done with German scientists in the USA. One of the arrivals was the nuclear physicist Hines Pose, who for some time headed the Obninsk laboratory V. So the first nuclear power plant owes its discovery not only to Soviet, but also to German scientists.

The world's first nuclear power plant was developed at the Kurchatov Laboratory No. 2 and at NIIkhimmash under the leadership of Nikolai Dollezhal. Dollezhal was appointed chief designer of the nuclear reactor of the future nuclear power plant. They created the first nuclear power plant in the world in the Obninsk laboratory B, all the work was supervised by Igor Vasilyevich Kurchatov himself, who was considered the "father of the atomic bomb", and now they wanted to make him the father of nuclear energy.

At the beginning of 1951, the nuclear power plant project was only at the development stage, but the building for the nuclear power plant had already begun to be built. Heavy structures made of iron and concrete that could not be modified or expanded already existed, and the nuclear reactor was still not fully designed. Later, the builders will have another headache - to insert a nuclear installation into an already finished building.

It is interesting that the first nuclear power plant in the world was designed in such a way that fuel rods - thin tubes that are placed in a nuclear installation, were placed not uranium pellets, as they are today, but uranium powder, made from uranium and molybdenum alloys. The first 512 fuel rods for the launch of the nuclear power plant were made at a plant in the city of Elektrostal, each of them was tested for strength, they did it manually. Hot water of the required temperature was poured into the TVEL, by the reddening of the tube, scientists determined whether the metal could withstand high temperature. There were a lot of defective products in the first batches of TVELs.

Interesting facts about the world's first nuclear power plant

1. Obninsk nuclear power plant, the first nuclear power plant in the USSR, was equipped with a nuclear reactor, which was named AM. At first, these letters were deciphered as "atom of the sea", because. they planned to use the installation on nuclear submarines, but later it turned out that the structure was too large and heavy for a submarine, and AM began to be deciphered as “peaceful atom”.
2. The world's first nuclear power plant was built in record time short time. Only 4 years passed from the start of construction to its commissioning.
3. According to the project, the first nuclear power plant cost 130 million rubles. In terms of our money, this is about 4 billion rubles. This is the amount allocated for its design and construction.

Launch of the world's first nuclear power plant

The launch of the world's first nuclear power plant took place on May 9, 1954, the nuclear power plant operated in idle mode. On June 26, 1954, she gave the first electric current, an energy launch was carried out.
What power did the first nuclear power plant in the USSR produce? Only 5 MW - the first nuclear power plant operated at such a small capacity.

The world community took the news that the world's first nuclear power plant was launched with pride and jubilation. For the first time in the world, man used the energy of the atom for peaceful purposes; this opened up great prospects and opportunities for the further development of energy. Nuclear physicists of the world called the launch of the Obninsk station the beginning of a new era.

During its operation, the first nuclear power plant in the world failed many times, the instruments suddenly broke down and gave a signal for an emergency shutdown of a nuclear reactor. Interestingly, according to the instructions, it takes 2 hours to restart the reactor, but the station workers learned to restart the mechanism in 15-20 minutes.

Such a quick response was needed. And not because they did not want to stop the supply of electricity, but because the first nuclear power plant in the world became a kind of exhibition exhibit and almost daily foreign scientists came there to study the operation of the station. To show that the mechanism does not work means to get big problems.

The consequences of the launch of the world's first nuclear power plant

At the Geneva Conference in 1955, Soviet scientists announced that they had built an industrial nuclear power plant for the first time in the world. After the report, the hall gave the physicists a standing ovation, even though applause was prohibited by the rules of the meeting.

After the first nuclear power plant was launched, active research began in the field of application nuclear reactions. There were projects of nuclear cars and aircraft, the energy of atoms was even going to be used in the fight against pests of grain and for the sterilization of medical materials.

Obninsk NPP has become a kind of impetus for the opening of nuclear power plants around the world. By studying its model, it was possible to design new stations and improve their work. In addition, using the NPP operation schemes, it was designed nuclear icebreaker and improved nuclear Submarine.

The first nuclear power plant operated for 48 years. In 2002, its nuclear reactor was shut down. Today, on the territory of the Obninsk NPP there is a kind of museum of nuclear energy, which is visited with excursions by both ordinary schoolchildren and famous personalities. For example, recently the English Prince Michael of Kent visited the Obninsk NPP. In 2014, the first nuclear power plant celebrated its 60th anniversary.

Opening of nuclear power plants in the world

The first nuclear power plant in the USSR was the beginning of a long chain of discoveries of new nuclear power plants in the world. New nuclear power plants used more and more advanced and powerful nuclear reactors. A 1000 MW nuclear power plant has become a commonplace in modern world power industry.

The first nuclear power plant in the world worked with a graphite-water nuclear reactor. After that, many countries began to experiment with the design of nuclear reactors and invented new types of them.

1. In 1956, the world's first nuclear power plant with a gas-cooled reactor, the Calder Hall Nuclear Power Plant in the United States, opened.
2. In 1958, the Shippingport Nuclear Power Plant was opened in the United States, but with a pressurized water reactor.
3. The first nuclear power plant with a boiling nuclear reactor - the Dresden Nuclear Power Plant, opened in the USA in 1960.
4. In 1962, the Canadians built a nuclear power plant with a heavy water reactor.
5. And in 1973, the world saw the Shevchenko NPP, built in the USSR - this is the first nuclear power plant with a breeder reactor.

Nuclear power today

How many nuclear power plants are there in the world? 192 nuclear power plants. Today, the map of nuclear power plants in the world covers 31 countries. There are 450 power units in all countries of the world, and another 60 power units are under construction. All nuclear power plants in the world have a total capacity of 392,082 MW.

Nuclear power plants in the world are concentrated mainly in the United States, America is the leader in terms of installed capacity, but in this country, nuclear power accounts for only 20% of the entire energy system. 62 US nuclear power plants provide a total capacity of 100,400 MW.

The second place in terms of installed capacity is occupied by the leader of nuclear power plants in Europe - France. Nuclear power in this country is a national priority and accounts for 77% of the total electricity production. In total, France has 19 nuclear power plants with a total capacity of 63,130 MW.

France also has a nuclear power plant with the most powerful reactors in the world. There are two water-water power units operating at the Sivo nuclear power plant. The capacity of each of them is 1561 MW. No nuclear power plant in the world can boast of such strong reactors.
Japan ranks third in the ranking of the most "advanced" countries in nuclear energy. It is in Japan that the most powerful nuclear power plant in the world is located in terms of the total amount of energy generated at nuclear power plants.

The first nuclear power plant in Russia

It would be wrong to hang the label “the first nuclear power plant in Russia” on the Obninsk NPP, because Soviet scientists who came from all over the USSR and even from beyond its borders worked on its creation. After the collapse of the Union in 1991, all nuclear power began to belong to those already independent countries on whose territory they were located.

After the collapse of the USSR, independent Russia inherited 28 nuclear reactors with a total capacity of 20,242 MW. Since gaining independence, the Russians have opened 7 more power units with a total capacity of 6,964 MW.

It is difficult to determine where the first nuclear power plant was opened in Russia, because Basically, Russian nuclear scientists open new reactors in existing nuclear power plants. The only station, all the power units of which were opened in independent Russia, is the Rostov NPP, which can even be called “the first NPP in Russia”.

The first nuclear power plant in Russia was designed and built back in the days of the USSR, in 1977 construction works, in 1979 her project was finally approved. Yes, we did not mix up anything, work at the Rostov NPP began before the scientists completed the final project. In 1990, the construction was frozen, and this despite the fact that the 1st block of the station was 95% ready.

The construction of the Rostov NPP was resumed only in 2000. In March 2001, the first nuclear power plant in Russia officially began to operate, however, so far with one nuclear reactor instead of the planned four. In 2009, the second power unit of the station began to operate, in 2014 - the third. In 2015, the first nuclear power plant of independent Russia acquired the 4th power unit, which, by the way, has not yet been completed and not put into operation.

The first nuclear power plant in Russia is located in the Rostov region near the city of Volgodonsk.

US nuclear power plant

If the first nuclear power plant in the USSR appeared in 1954, then the nuclear power plant map of America was replenished only in 1958. Given the ongoing competition between the Soviet Union and the United States in the field of energy (and not only energy), 4 years was a serious lag.

The first US nuclear power plant was the Shippingport Nuclear Power Plant in Pennsylvania. The first nuclear power plant in the USSR had a capacity of only 5 MW, the Americans went further, and Shippingport already had a capacity of 60 MW.
The active construction of the US nuclear power plant continued until 1979, when an accident occurred at the Three Mile Island station, due to the mistakes of the station workers, nuclear fuel melted. It took 14 years to eliminate the accident at this US nuclear power plant, it took more than a billion dollars. The accident at Three Mile Island temporarily halted the development of nuclear power in America. Today, however, the United States has the largest number of nuclear power plants in the world.

As of June 2016, the map of US nuclear power plants includes 100 nuclear reactors with a total capacity of 100.4 GW. Four more reactors with a total capacity of 5 GW are under construction. US nuclear power plants generate 20% of all electricity in this country.

The most powerful US nuclear power plant today is the Palo Verde nuclear power plant, it can provide electricity to 4 million people and provide a capacity of 4,174 MW. By the way, the US Palo Verde nuclear power plant is also included in the top “Largest nuclear power plants in the world”. There, this nuclear station is in 9th place.

The largest nuclear power plants in the world

A 1000W nuclear power plant once seemed like the unattainable pinnacle of nuclear science. Today, the map of nuclear power plants in the world includes huge giants of nuclear energy with capacities of 6, 7, 8 thousand megawatts. What are they, the largest nuclear power plants in the world?

The largest and most powerful nuclear power plants in the world today include:

1. Paluel nuclear power plant in France. This nuclear power plant operates on 4 power units with a total capacity of 5,528 MW.
2. French NPP Gravelines. This nuclear power plant in northern France is considered the largest and most powerful in its country. This nuclear power plant has 6 reactors with a total capacity of 5,460 MW.
3. Hanbit Nuclear Power Plant (another name Yongvan) is located in the southwest of South Korea on the coast of the Yellow Sea. Its 6 nuclear reactors give a power of 5,875 MW. It is interesting that the Yongvan NPP was renamed Hanbit at the request of the fishermen of the Yongvan town where the station is located. Fish sellers did not want their products to be associated worldwide with nuclear power and radiation. This reduced their profits.
   4. Hanul NPP (formerly Khulchin NPP) is also a South Korean nuclear power plant. It is noteworthy that the Hanbit nuclear power plant, it exceeds only 6 MW. Thus, the capacity of the Hanul station is 5,881 MW.
   5. Zaporozhye NPP is the most powerful NPP in Europe, Ukraine and the entire post-Soviet space. This station is located in the city of Energodar. 6 nuclear reactors give a power of 6000 MW. The construction of the Zaporizhzhya NPP began in 1981, and in 1984 it was put into operation. Today, this station generates a fifth of Ukraine's total electricity and half of the country's nuclear energy.

The most powerful nuclear power plant in the world

NPP Kashiwazaki-Kariva - such an intricate name is the most powerful nuclear power plant. It operates 5 boiling water reactors and two advanced boiling water reactors. Their total capacity is 8,212 MW (for comparison, we know that the first nuclear power plant in the world was only 5 MW). The most powerful nuclear power plant in the world was built from 1980 to 1993. Here are a few interesting facts about this nuclear power plant.

1. As a result of a powerful earthquake in 2007, Kashiwazaki-Kariwa received many different damages, several containers with low radioactive waste overturned, and radioactive water leaked into the sea. Due to the earthquake, the filters of the nuclear power plant were damaged and radioactive dust escaped from the station.
2. The total damage from the earthquake in Japan in 2007 is estimated at 12.5 billion dollars. Of these, 5.8 billion losses were "taken" for repairs by the most powerful nuclear power plant in the world, Kashiwazaki-Kariva.
3. Interestingly, until 2011, another Japanese nuclear power plant could be called the most powerful nuclear power plant. Fukushima 1 and Fukushima 2 were essentially the same nuclear power and together generated 8,814 MW.
4. The large total power of a nuclear power plant does not mean at all that it uses the strongest nuclear reactors. The maximum capacity of one of the reactors at Kashiwazaki-Kariwa is 1315 MW. The station achieves a large final power due to the fact that 7 nuclear reactors operate in it.

More than 60 years have passed since the opening of the first nuclear power plant in the world. During this time, nuclear energy has stepped far forward, developing new types of nuclear reactors and increasing the power of nuclear power plants by a thousand times. Today, the nuclear power plants of the world are a huge energy empire, which is developing more and more every day. We are confident that the state of nuclear power plants in the world today is far from the limit. Nuclear energy has a great and bright future.

Nuclear power plants

Nuclear power plants are nuclear installations that produce energy, while observing the specified modes at certain conditions. For these purposes, the territory defined by the project is used, where nuclear reactors are used in combination with necessary systems, devices, equipment and facilities. For execution targets specialized staff is involved.

All nuclear power plants in Russia

The history of nuclear energy in our country and abroad

The second half of the 1940s was marked by the beginning of work on the creation of the first project involving the use of a peaceful atom to generate electricity. In 1948, I.V. Kurchatov, guided by the instructions of the party and the Soviet government, made a proposal to start work on the practical use of atomic energy to generate electricity.

Two years later, in 1950, not far from the village of Obninskoye, located in the Kaluga region, the construction of the first nuclear power plant on the planet was launched. The launch of the world's first industrial nuclear power plant, with a capacity of 5 MW, took place on 06/27/1954. The Soviet Union became the first power in the world to succeed in using the atom for peaceful purposes. The station was opened in Obninsk, which had received the status of a city by that time.

But Soviet scientists did not stop there, they continued to work in this direction, in particular, only four years later, in 1958, the operation of the first stage of the Siberian NPP was started. Its power was many times greater than the station in Obninsk and amounted to 100 MW. But for domestic scientists, this was not the limit, upon completion of all work, the design capacity of the station was 600 MW.

In the vastness of the Soviet Union, the construction of nuclear power plants, at that time, took on a massive scale. In the same year, the construction of the Beloyarsk NPP was launched, the first stage of which, already in April 1964, supplied the first consumers. The geography of the construction of nuclear power plants entangled the whole country with its network, in the same year they launched the first unit of the nuclear power plant in Voronezh, its capacity was 210 MW, the second unit launched five years later in 1969, boasted a capacity of 365 MW. the boom in the construction of nuclear power plants did not subside throughout the Soviet era. New stations, or additional units already built, were launched at intervals of several years. So, already in 1973, Leningrad received its own nuclear power plant.

However, the Soviet state was not the only one in the world who was able to master such projects. In the UK, they also did not doze off and, realizing the prospects of this direction, actively studied this issue. Just two years later, after the opening of the station in Obninsk, the British launched their own project for the development of peaceful atom. In 1956, the British launched their own station in the town of Calder-Hall, the power of which exceeded the Soviet counterpart and amounted to 46 MW. Not lagging behind on the other side of the Atlantic, a year later, the Americans solemnly launched the station in Shippingport. The capacity of the facility was 60 MW.

However, the development of the peaceful atom was fraught with hidden threats, which the whole world soon learned about. The first sign was a major accident in Three Mile Island that occurred in 1979, but after it there was a disaster that hit the whole world, in the Soviet Union, in small town Chernobyl was a large-scale disaster, it happened in 1986. The consequences of the tragedy were irreparable, but besides this, this fact made the whole world think about the advisability of using nuclear energy for peaceful purposes.

World luminaries in this industry are seriously thinking about improving the safety of nuclear facilities. The result was the founding assembly, which was organized on May 15, 1989 in the Soviet capital. The Assembly decided to create a World Association, which should include all operators of nuclear power plants, its generally recognized abbreviation is WANO. In the course of implementing its programs, the organization systematically monitors the increase in the level of safety of nuclear power plants in the world. However, despite all the efforts made, even the most modern and at first glance seemingly safe objects cannot withstand the onslaught of the elements. It was because of the endogenous catastrophe, which manifested itself in the form of an earthquake and the tsunami that followed it, in 2011 there was an accident at the Fukushima-1 station.

Atomic blackout

NPP classification

Nuclear power plants are classified according to two criteria, the type of energy they produce and the type of reactors. Depending on the type of reactor, the amount of generated energy, the level of safety, and also what kind of raw materials are used at the station are determined.

According to the type of energy that stations produce, they are divided into two types:

Nuclear power plants. Their main function is to generate electrical energy.

Nuclear thermal power plants. Due to the heating plants installed there, which use the heat losses that are inevitable at the station, it becomes possible to heat the network water. Thus, these stations, in addition to electricity, generate thermal energy.

After examining many options, scientists came to the conclusion that the most rational are their three varieties, which are currently used throughout the world. They differ in a number of ways:

1. Fuel used;
2. Applied coolants;
3. Cores operated to maintain the required temperature;
4. A type of moderator that determines the reduction in the speed of neutrons that are released during decay and are so necessary to support a chain reaction.

The most common type is the reactor, which uses enriched uranium as fuel. Ordinary or light water is used here as a coolant and moderator. Such reactors are called light water, there are two types of them. In the first, the steam used to turn the turbines is generated in an active zone called a boiling water reactor. In the second, steam generation takes place in the external circuit, which is connected to the primary circuit through heat exchangers and steam generators. This reactor began to be developed in the fifties of the last century, the basis for them was the US army programs. At the same time, at about the same time, the Soyuz developed a boiling water reactor, in which a graphite rod acted as a moderator.

It is the type of reactor with a moderator of this type that has found application in practice. We are talking about a gas-cooled reactor. Its history began in the late forties, early fifties of the XX century, initially the development of this type was used in the production of nuclear weapons. In this regard, two types of fuel are suitable for it, these are weapons-grade plutonium and natural uranium.

The latest project, which was accompanied by commercial success, was a reactor where heavy water is used as a coolant, and natural uranium, already familiar to us, is used as fuel. Initially, several countries designed such reactors, but as a result, their production was concentrated in Canada, which is the reason for the presence of massive deposits of uranium in this country.

Thorium nuclear power plants - the energy of the future?

History of improving the types of nuclear reactors

The reactor of the first nuclear power plant on the planet was a very reasonable and viable design, which was proved during the long-term and flawless operation of the station. Among its constituent elements were:

1. side water protection;
2. masonry casing;
3. top cover;
4. prefabricated collector;
5. fuel channel;
6. top plate;
7. graphite masonry;
8. bottom plate;
9. distribution manifold.

Stainless steel was chosen as the main structural material for TVEL cladding and technological channels; at that time, it was not known about zirconium alloys, which could be suitable for operation at a temperature of 300°C. The cooling of such a reactor was carried out with water, while the pressure under which it was supplied was 100 at. In this case, steam was released with a temperature of 280°C, which is quite a moderate parameter.

The channels of a nuclear reactor were designed in such a way that it was possible to completely replace them. This is due to the limitation of the resource, which is due to the time spent by the fuel in the activity zone. The designers found no reason to expect that the structural materials located in the zone of activity under irradiation will be able to work out their entire resource, namely about 30 years.

As for the design of the TVEL, it was decided to adopt a tubular version with a one-sided cooling mechanism

This reduced the likelihood that fission products would enter the circuit in the event of a fuel element failure. To regulate the temperature of the TVEL cladding, a fuel composition of a uranomolybdenum alloy was used, which had the form of grains dispersed by means of a warm-water matrix. The nuclear fuel processed in this way made it possible to obtain highly reliable fuel elements. capable of operating under high thermal loads.

The infamous Chernobyl nuclear power plant can serve as an example of the next round in the development of peaceful nuclear technologies. At that time, the technologies used in its construction were considered the most advanced, and the type of reactor the most modern in the world. We are talking about the RBMK-1000 reactor.

The thermal power of one such reactor reached 3200 MW, while it has two turbogenerators, the electric power of which reaches 500 MW, so one power unit has an electric power of 1000 MW. Enriched uranium dioxide was used as fuel for the RBMK. In the initial state before the start of the process, one ton of such fuel contains about 20 kg of fuel, namely uranium - 235. With stationary loading of uranium dioxide into the reactor, the mass of the substance is 180 tons.

But the loading process is not a bulk, fuel elements are placed in the reactor, already well known to us TVEL. In fact, they are tubes, for the creation of which a zirconium alloy is used. As contents, they contain uranium dioxide tablets, which have a cylindrical shape. In the reactor activity zone, they are placed in fuel assemblies, each of which combines 18 fuel elements.

There are up to 1700 such assemblies in such a reactor, and they are placed in a graphite masonry, where technological channels of a vertical shape are specially designed for these purposes. It is in them that the coolant circulates, the role of which, in the RMBC, is played by water. A whirlpool of water occurs when exposed to circulation pumps, of which there are eight pieces. The reactor is located inside the shaft, and the graphic masonry is located in a cylindrical body 30 mm thick. The support of the entire apparatus is a concrete base, under which there is a pool - a bubbler, which serves to localize the accident.

The third generation of reactors uses heavy water

The main element of which is deuterium. The most common design is called CANDU, it was developed in Canada and is widely used around the world. The core of such reactors is located in a horizontal position, and cylindrical tanks play the role of a heating chamber. The fuel channel stretches through the entire heating chamber, each of these channels has two concentric tubes. There are outer and inner tubes.

In the inner tube, the fuel is under coolant pressure, which makes it possible to additionally refuel the reactor during operation. Heavy water with formula D20 is used as a moderator. During a closed cycle, water is pumped through the pipes of the reactor containing bundles of fuel. As a result of nuclear fission, heat is released.

The cooling cycle when using heavy water consists in passing through steam generators, where ordinary water boils from the heat released by heavy water, as a result of which high-pressure steam is formed. It is distributed back to the reactor, resulting in a closed cooling cycle.

It was along this path that the step-by-step improvement of the types of nuclear reactors that were and are being used in various countries of the world took place.