The smallest nuclear reactor. The miniature nuclear reactor in each house is real! (video). What in the chest

The microater reactor for household needs, unfortunately, it is impossible to create and that is why. The operation of the atomic reactor is based on the chain reaction of the splitting of uranium-235 nuclei (²³⁵) thermal neutron: n + ²³⁵u → ⁴⁴⁴Ba + ⁹²kr + γ (202.5 MeV) + 3N. The drawing of the chain reaction of splitting is shown below.

In fig. It can be seen as a neutron, falling into the kernel (²³⁵u) excites it and the kernel is split into two fragments (⁴⁴⁴ba, ⁹²kr), γ-quantum with an energy of 202.5 MeV and 3 free neutron (on average), which in turn can split the following 3 uranium cores turned out to be on their way. So in the process of each splitting act, about 200 MeV of energy or ~ 3 × 10⁻⁻⁻¹ J, which corresponds to ~ 80 terraj / kg or 2.5 million times more than it would be highlighted in the same amount of burning coal. But as Murphy instructs us: "If the trouble should happen, then it must happen," and part of neutrons born during splitting is lost in the process of chain reaction. Neutrons can exit (jump out) from an active volume or absorb impurities (for example Krypton). The ratio of the number of neutrons of the subsequent generation to the neutron number in the preceding generation throughout the volume of the breeding neutron medium (the active zone of the nuclear reactor) is called the neutron reproduction coefficient, k. At K.<1 цепная реакция затухает, т.к. число поглощенных нейтронов больше числа вновь образовавшихся. При k>1 Almost instantly occurs explosion. Print K equal to 1 is a controlled stationary chain reaction. The neutron reproduction coefficient (K) is most sensitive to the mass and purity of nuclear fuel (²³⁵u). In nuclear physics, the minimum mass of the inflicted substance necessary for the start of the self-sustaining chain reaction of the division (K≥1) is called a critical mass. For uranium-235, it is 50 kg. This is certainly not a micro-size, but also a little. To avoid a nuclear explosion and create the ability to control the chain reaction (coefficient of reproduction), in the reactor mass of fuel, it is necessary to increase and accordingly put into operation the absorbers (moderators) of neutrons. That is this engineering and technical equipment of the reactor, with the aim of sustainable chain reaction control, the cooling system and additional facilities for the radiation safety of personnel, and require large volumes.

You can also use California-232 with a critical mass of about 2.7 kg as fuel. In the limit to bring the reactor to the size of the ball with a diameter of several meters is probably quite possible. Most likely it is done probably on nuclear submarines. I think to approach such reactors should be very dangerous ☠ due to the inevitable neutron background, but it is already necessary to ask the warrior about it.

California is not suitable as a nuclear fuel in view of its vast value. 1 gram of California-252 costs about 27 million dollars. Only uranium is widely used as nuclear fuel. Fuel cells based on thorium and plutonium have not yet received widespread, but are actively being developed.

The relatively high compactness of submarine reactors is ensured by the distribution difference (water-water reactors, VVER / PWR) are usually used, different requirements for them (other requirements of the security and emergency stop; on board it is usually no need for a lot of electricity, unlike the reactors of ground power plants which is only for the sake of electricity and were created) and the use of different degrees of fuel enrichment (uranium-235 concentrations with respect to the concentration of uranium-238). Usually, in fuel for marine reactors, uranium is used with a much higher degree of enrichment (from 20% to 96% for American boats). Also, in contrast to ground power plants, where the use of fuel in the form of ceramics (uranium dioxide) is common in marine reactors is most often used as fuel of uranium alloys with zirconium and other metals.

Devices generating electrical current as a result of using the energy of nuclear decay, well studied (since 1913) and have long been mastered in production. Basically, they are used where relative compactness and high autonomy are needed - in the research of space, underwater devices, low-spirited and deserted technologies. Prospects for their use in domestic conditions are quite modest, in addition to radiation hazards, most types of nuclear fuel have high toxicity and in principle are extremely unsafe when contacting the environment. Despite the fact that in the English literature, these devices are referred to atomic batteries, and they are not accepted by reactors, they can be considered as such, because they are a decay reaction. If desired, such devices can be adapted for household needs, it may be relevant for conditions, for example, Antarctica.

Radioisotope thermoelectric generators have long existed and fully satisfy your request - they are compact and powerful enough. They work at the expense of the Seebeck effect, moving parts do not have. If it did not contradict common sense, safety and criminal code, such a generator could be buried somewhere under the garage at the cottage and even put a couple of bulbs and a laptop from it. To donate so to speak the health of descendants and neighbors for the sake of hundreds and other watts of electricity. In total, more than 1000 were produced in Russia and the USSR.

As other participants already answered, the prospects for miniaturization of the "classic" reactors of nuclear power using steam turbines to generate electricity are strongly limited to the laws of physics, and the main restrictions imposes not so much the size of the reactor, how many sizes of other equipment: boilers, pipelines, turbines, cooling boilers. "Household" models will most likely not be. Nevertheless, quite compact devices are currently being actively developed, for example, the promising Nuscale reactor at a capacity of 50 MWE has a size of only 76 by 15 inches, i.e. About two meters by 40 centimeters.

With the energy of nuclear synthesis, everything is much more difficult and ambiguous. On the one hand, it can only be about the future. Until energy, even large reactors of nuclear synthesis and speech about their practical miniaturization simply does not go. Nevertheless, a number of serious and even more serious organizations are developing compact energy sources based on the synthesis reaction. And if in the case of Lockhid-Martin, under the word "compact" is understood as "size with a van", then, for example, in the case of the American Agency Darpa, which allocated in 2009 fiscal year

Chinese scientists working at the Institute for Nuclear Energy Safety Institute began to work on the creation of a nuclear power plant, which will become the smallest in the world. Reports about it.

A nuclear power plant will be a reactor on fast neutrons. Scientists themselves called her "portable nuclear battery." This design will allow you to work out a reactor without complex maintenance conditions for 5 years. Milked lead will be used for cooling.

The power plant of small sizes will be able to produce up to 10 megawatts of electricity. In this case, its dimensions will be only 2 meters wide and 6 meters in height. According to scientists, it will be able to supply energy about 50 thousand houses. Despite this, the first point of operation of the new reactor scientists chose the plant for the desalination of water, which is located in the South China Sea.

The Chinese authorities intend to introduce such "portable nuclear batteries" into operation over the next 5 years.

1. The free stirling engine operates from the heating "atomic ferry" 2. The induction generator gives about 2 W electric power to power the incandescent lamp 3. A characteristic blue glow is the Cherenkov radiation of electrons emitted from gamma quanta atoms. Can serve as a great night light!


For children from 14 years, the young researcher will be able to independently assemble the small but real nuclear reactor, to know what instantaneous and delayed neutrons, and see the dynamics of overclocking and braking chain nuclear reaction. A few simple experiments with a gamma spectrometer will be able to deal with the development of various fission products and experiment with the reproduction of fuel from the fashionable thorium (a piece of sulfide thorium-232 is attached). The book "Basics of nuclear physics for the smallest" book contains a description of more than 300 experiments with the collected reactor, so that the scope for creativity is huge


The historical prototype set Atomic Energy Lab (1951) gave the opportunity to students join the most advanced area of \u200b\u200bscience and technology. Electroscope, Wilson Camera and Geiger Muller Counter allowed a lot of interesting experiences. But, of course, not so interesting as the assembly of the active reactor from the Russian set "Table NPP"!

In the 1950s, with the advent of atomic reactors, before humanity, it would seem that the brilliant prospects for solving all energy problems were issued. Energy engineers designed nuclear power plants, shipbuilders - atomic electric power plants, and even autocontstructors decided to join the holiday and use the "peaceful atom". In society there was a "atomic boom", and the industry began to miss the qualified specialists. The influx of new personnel was required, and a serious educational company was deployed not only among university students, but also among schoolchildren. For example, A.c. Gilbert Company released in 1951 children's set Atomic Energy Lab, containing several small radioactive sources, necessary devices, as well as samples of uranium ore. This "written scientific set", as was written on the box, allowed "young researchers to spend more than 150 exciting scientific experiments."

Frames decide everything

Over the past half a century, scientists received several bitter lessons and learned how to build reliable and safe reactors. And although now in this area there is a decline caused by a recent accident on Fukushima, soon it will again be replaced by the rise, and the NPP will continue to be considered as an extremely promising method of obtaining clean, reliable and safe energy. But now the lack of personnel is felt in Russia as the IV 1950s. To attract schoolchildren and increase interest in nuclear power, a scientific and production enterprise (NPP) "EcoatomConversion", taking an example with A.c. Gilbert Company, released an educational set for children from 14 years. Of course, the science for these half a century did not stand in place, so, unlike its historical prototype, the modern set allows you to get a much more interesting result, namely, to assemble the most real layout of the nuclear power plant on the table. Of course, acting.

Literacy with diaper

"Our company is from Obninsk, where atomic energy is familiar and habitual people almost from kindergarten," explains the "PM" scientific director of the NPP "Ecoatomclosure" Andrei Vyhadanko. - And everyone understands that it is not necessary to be afraid. After all, only unknown danger is truly terrible. Therefore, we decided to release this set for schoolchildren, which will allow them to specifically experiment and explore the principles of the operation of atomic reactors without exposing themselves and surrounding serious risk. As you know, the knowledge gained in childhood is the most durable, so that we release this set we hope to significantly reduce the likelihood of repetition of Chernobyl or

Fukushima in the future. "

Unnecessary plutonium

Over the years of operation, the set of NPPs accumulated tons of so-called reactor plutonium. It consists mainly of weapons Pu-239 containing about 20% of the impurities of other isotopes, primarily PU-240. This makes the reactor plutonium absolutely unsuitable for the creation of nuclear bombs. The separation of impurities is very complex, since the difference between the masses between the 239th and 240th isotopes is only 0.4%. The manufacture of nuclear fuel with the addition of reactor plutonium was technologically complex and economically unprofitable, so that this material remained not to cases. It is the "thrus" plutonium and used in the "set of a young atrocker" developed by the NPP "Ecoatomclosure".

As is known, for the beginning of the chain fission reaction, nuclear fuel should have a certain critical mass. For a ball of weapons uranium-235, it is 50 kg, from plutonium-239 - only 10. Sheath from the neutron reflector, such as beryllium, can reduce the critical mass several times. And the use of a moderator, as in thermal neutron reactors, will reduce the critical mass of more than ten times to several kilograms of highly enriched U-235. The critical mass of PU-239 and will make hundreds of grams at all, and it is such a super-compact reactor that fit on the table, developed in "ecoatom conversions".

What in the chest

The packaging of the set is modestly decorated in black and white colors, and only non-latch three-segment radioactivity icons are somewhat allocated on a general background. "There is no danger in fact no," says Andrei, pointing to the words "completely safe!", Written on the box. - But these are the requirements of official instances. " The box is heavy, which is not surprising: it contains a hermetic transport lead container with a fuel assembly (fueling) of six plutonium rods with a zirconium sheath. In addition, the set includes an external body of a heat-resistant glass reactor with a chemical hardening, a housing cover with a glass window and handwritten, the body of the active stainless steel zone, a reactor stand, controlling the boron carbide drive. The electrical part of the reactor is represented by free stirling engine with connecting polymer tubes, a small incandescent lamp and wires. The kit also includes a kilogram package with boric acid powder, a pair of protective suits with respirators and a gamma spectrometer with a built-in neutron helium detector.

Building nuclear power plants

The assembly of the current layout of the NPP on the attached leadership in pictures is very simple and takes less than half an hour. Nading a stylish protective suit (it is only needed for the time of assembly), we open hermetic packaging with fuel assembly. Then we insert the assembly inside the reactor housing, cover the active zone body. Under the end, we snap the cover with the handle with the handle. In the center you need to insert to the end of the stem-absorber, and through any of the other two, fill the active zone with distilled water to the line on the housing. After filling, the tubes for steam and condensate are connected to the hemovers passing through the stirling engine heat exchanger. NPP itself is completed and ready for launch, it remains only to place it on a special stand into an aquarium filled with a solution of boric acid, which perfectly absorbs neutrons and protects the young researcher from neutron irradiation.

Three, two, one - Start!

Move the gamma spectrometer with neutron sensors close to the wall of the aquarium: a small part of neutrons, which does not represent a threat to health, still comes out. Slowly raise the adjusting rod before the start of rapid growth of the neutron flow, meaning the launch of the self-sustaining nuclear reaction. It remains only to wait for the output to the desired power and to dwell the rod back to the labels, so that the reaction rate is stabilized. As soon as the boil begin, a pair layer appears in the upper part of the body of the active zone (perforation in the housing does not allow this layer to bargain plutonium rods, which could lead to overheating). Couples on the tube goes up, to the stirling engine, it is condensed and runs down on the output tube down the inside of the reactor. The temperature difference between the two ends of the engine (one is heated by steam, and the other is cooled by room air) is converted to fluctuations in the magnet piston, and the one, in turn, suggests an alternating current in the winding surrounding engine, igniting the atomic light in the hands of a young researcher and, as hoping Developers, atomic interest in his heart.

Editor's Note: This article was published in the April issue of the journal and is the first-air drawing.

Recently, the concept of autonomous power supply is gaining more and more development. Whether it is a country house with its windmills and solar panels on the roof or a woodworking plant with a heating boiler, working on production - sawdust, the essence does not change. The world gradually comes to the fact that it is time to abandon centralized providing heat and electricity. Central heating in Europe is almost not found, individual homes, apartment skyscrapers and industrial enterprises are heated independently. The exception is the individual cities of the northern countries - there are centralized heating and large boilers are justified by climatic conditions.

As for the autonomous electric power industry, everything goes to this - the population is actively buying windmills and solar panels. Enterprises are looking for ways to rational use of thermal energy from technological processes, build their own thermal power plants and also bother solar panels with windmills. Especially rotated on the "green" technologies even plan to cover the roofs of the roofs of factory workshops and hangars.

Ultimately, it turns out to be cheaper than buying the necessary energy facilities from local energy seals. However, after the Chernobyl accident, all somehow have forgotten that the energy of the atom remains the most environmentally friendly, cheap and affordable way of obtaining heat and electrical energy. And if, throughout the existence of the nuclear industry, the power plant with nuclear reactors has always been associated with complexes on the hectares of the square, huge pipes and lakes for cooling, then a number of recent developments are designed to break these stereotypes.

Several companies immediately stated that they were entering the market with "home-made" nuclear reactors. Miniature stations with dimensions from garage boxing to a small two-story building are ready to supply from 10 to 100 MW for 10 years without refueling. Reactors are fully autonomous, safe, do not require maintenance and after the service life is simply recharged for another 10 years. What is not a dream for a plant for the production of irons or a household house? Consider in more detail those of which will begin in the coming years.

Toshiba 4S (Super Safe, Small and Simple)

The reactor is designed by the type of battery. It is assumed that such a "battery" will be buried in a mine in a depth of 30 meters, and the building above it will have dimensions 22 16 11 meters. Not many more good country houses? Such a station will need attendants, but it still does not go to comparison with tens of thousands of square meters of square and hundreds of workers at traditional nuclear power plants. Rated power of the complex - 10 megawatts for 30 years without refueling.

The reactor works on fast neutrons. A similar reactor is established and operates since 1980 at the Beloyarsk NPP in the Sverdlovsk region of Russia (BN-600 reactor). The principle of operation is described. In the Japanese installation, the sodium melt is used as a coolant. This allows you to work to raise the temperature of the reactor to 200 degrees Celsius compared with water and under normal pressure. The use of water in this capacity would give rise to the pressure in the system hundreds of times.

The most important thing is the cost of working out 1 kW hour for this installation is expected at the level of 5 to 13 cents. The scatter is due to the peculiarities of national taxation, different costs of recycling nuclear waste and the value of the introduction of the station itself.

The first customer of "batteries" from Toshiba seems to be a small town of Galena Alaska in the United States. Currently there is a coordination of permits with American government agencies. The company's partner in the United States is Westinghouse, who first put the fuel assemblies of alternative Russian TVEL for the first time in the Ukrainian NPP.

Hyperion Power Generation and Hyperion Reactor

These American guys look like the first to enter the commercial market of miniature nuclear reactors. The company offers installations from 70 to 25 megawatt worth about $ 25-30 million per piece. Hyperion nuclear installations can be used both to generate electricity and heating. At the beginning of 2010, more than 100 orders at the station of different power have already arrived, with both individuals and state-owned companies. It is planned to even make the production of ready-made modules outside the United States, building factories in Asia and Western Europe.

The reactor works in the same principle as the majority of modern reactors in nuclear power plants. To read . The most common on the principle of action are the most common Russian-type Russian reactors and power plants, used on nuclear submarines of the project 705 "Lira" (NATO - "Alfa"). The American reactor is practically a land version of the reactors, installed on the specified submarines, by the way, the fastest submarines of their time.

Uranium nitride is used as fuel, which has a higher thermal conductivity compared to traditional VVER reactors with ceramic uranium oxide. This allows you to work at a temperature of 250-300 degrees Celsius is higher than water-water installations, which increases the efficiency of steam turbines of eleticrogenerators. Here everything is simple - the higher the temperature of the reactor, the higher the temperature of the steam and, as a result, above the efficiency of the steam turbine.

A lead-bismuth melt is used as a cooling "fluid", similar to that of Soviet APLs. The melt passes through three heat exchange circuits, reducing the temperature with 500 degrees Celsius to 480. The working fluid for the turbine can serve as water steam and superheated carbon dioxide.

Installation with fuel and cooling system has a mass of only 20 tons and is designed for 10 years of operation at a rated power of 70 megawatts without refueling. Impact really miniature sizes - the reactor has only 2.5 meters in height and 1.5 meters wide! The entire system can be transported on trucks or railway transport, being an absolute commercial world record holder in terms of power ratio.

Upon arrival at the place, the "barrel" with the reactor is simply buried. Access to it or any service is not expected at all. After the warranty period expires, the assembly is digging and sent to the manufacturer's factory to rewrite. Features of lead-bismuth cooling give a huge safety advantage - overheating and explosion (no pressure increases with increasing temperature). Also, when cooled, the alloy is frozen, and the reactor itself turns into an iron blank, not afraid of mechanical influences, isolated with a thick layer of lead. By the way, it is the impossibility of working on small capacities that precisely the frozen of the cooling alloy and the automatic shutdown) was the cause of refusing to further use lead bismuth plants on the submarine. For the same reason, these are the safest reactors of all, ever mounted on the submarine of all countries.

Initially, miniature nuclear power plants were developed by Hyperion Power Generation for the needs of the extractive industry, namely, for the processing of combustible shale into synthetic oil. Assessment reserves of synthetic oil in combustible shale, available for processing existing technologies are estimated at 2.8. -33 trillion barrels. For comparison, the reserves of "liquid" oil in wells are estimated in just 1.2 trillion barrels. However, the process of processing shale in oil requires their heating, followed by the capture of evaporation, which are then condensed into oil and by-products. It is clear that for heating you need to take energy somewhere. For this reason, oil production from the shale is considered economically inappropriate compared with its imports from OPEC countries. So the future of your product company sees in different applications.

For example, as a mobile power plant for the needs of military bases and airfields. There are also interesting prospects here. So, when conducting mobile hostilities, when troops operate from the so-called reference points in certain regions, these stations could feed the BAZ infrastructure. Like in computer strategies. With the only difference that when the task in the region is performed, the power plant is shipped to the vehicle (aircraft, cargo helicopter, trucks, train, ship) and take a new place.

Another use in the military sphere is stationary nutrition of permanent military bases and airfields. For air tax or rocket strike, the base with an underground nuclear power plant that does not require the service personnel is more likely to maintain combat capability. In the same way, a group of social infrastructure facilities can be used - the system of vocational relations of cities, administrative facilities, hospitals.

Well, industrial and civil application are the power supply systems of small cities and towns, individual enterprises or their groups, heating systems. After all, these installations primarily produce thermal energy and in the cold regions of the planet can be the core of centralized heating systems. Also promising the company considers the use of such mobile power plants on desalination plants in developing countries.

SSTAR (Small, Sealed, Transportable, Autonomous Reactor)

Small, sealed, mobile autonomous reactor - a project developed in Lawrence Livermore National Laboratory, USA. On the principle of operation is similar to Hyperion, only uranium-235 uses as fuel. Must have an expiration date of 30 years at power from 10 to 100 megawatts.

Dimensions should be 15 meters in height and 3 wide with a 200 ton reactor weigh. This unit is initially calculated for use in underdeveloped countries according to the leasing scheme. Thus, high attention is paid to the inability to disassemble the design and extract something valuable from it. Valuable is uranium-238 and weapons plutonies that are produced as the expiration date.

At the end of the lease agreement, the recipient will have to return this installation in the United States. But it seems to me that this is mobile plants for the production of weapons plutonium for other people's money? 🙂 In other matters, the American state here has not advanced further research, not even the prototype.

Summing up, it should be noted that while the most real is the development of Hyperion and the first deliveries are scheduled for 2014. I think you can expect the further offensive of the "pocket" NPP, especially since other enterprises, including such giants as Mitsubishi Heavy Industries, are also conducted similar to the creation of such stations. In general, a miniature nuclear reactor is a worthy answer to all kinds of tidal and tump and other incredibly "green" technologies. It seems that in the near future we will be able to observe how again military technologies are moving to civil service.

 

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