NUCLEAR POWER REACTORS
There are events that enter, no, burst into human life triumphantly, and leave a bright mark forever. Such an event in October 1957 was the launch of the world’s first artificial Earth satellite, which heralded the beginning of the space age. Such an event in April 1961 was the first in the world space flight of our Yuri Gagarin. The flight of a man, an earthling into space.
And there are events that only a modest newspaper note reports about and only specialists are aware of their importance. Without a doubt such an event was the launch of the world’s first nuclear power plant
built in our country. On this day, June 27 1954, Obninsk Nuclear Power Plant started generating electricity
and thereby laid the foundation for the age of use of nuclear energy for peaceful purposes.
The remarkable Soviet scientist Igor Vasilyevich Kurchatov, Anatoly Petrovich Alexandrov, Nikolai Antonovich Dollezhal, and many, many others stood at the origins of domestic nuclear energy. Why, a skeptic might ask, why do we need nuclear power stations if we have enough coal, oil, gas?
Let’s take a look into a nuclear reactor to answer this question. In the process of a chain reaction, nuclei of Uranium 235 are split into pieces and their energy is converted into heat. One kilogram of uranium-235 releases as much heat during the fission reaction as produced by burning and two and a half thousand tons of the best quality coal. Therefore first of all it is profitable to use nuclear fuel where there are no local fossil fuels available. That’s why, based on Obninsk’s experience, the Bilibinsk nuclear power station in Chukotka was built. For many years it has been providing the northerners with electricity and heat
and the cost of the produced energy turned out to be half that of imported fuel.
In the European part of the country where 80% of the industrial sector is concentrated coal reserves near Donbass are close to being exhausted, hydropower resources are almost exhausted and the known reserves of fossil fuels are between 3000 and 3500 kilometers to the East and South.This is why the question of the economic necessity of using nuclear fuel has been raised. By the way, this is the second answer to the question why we need the nuclear power plants. There is also a third answer. The fact is that some types of nuclear power plants with fast neutron reactors make it possible to simultaneously produce electrical energy and produce new nuclear fuel.
This is what the founder of the Russian nuclear power industry, Igor Vasilyevich Kurchatov, says: Unlike conventional fuels such as coal and oil, nuclear fuel used in nuclear reactors allows us to produce new elements such as plutonium and others, which don’t exist in nature and can also be used as nuclear fuel.
It is like burning coal in the furnace and raking out even more coal together with ashes.
Nuclear power stations can provide humankind with energy for centuries therefore we really need them.
The operating experimental nuclear reactors have revealed their significant advantages in comparison with thermal power plants. The cost of fuel in thermal stations is 85–90% of the cost of electricity
while in nuclear it is about 40 percent. That is why in the late 60s, two types of nuclear reactors were created optimal for the conditions of our country. This is a RBMK-1000, which means a high-power channel-type reactor with electric power output of 1000MW. The first one was installed at the Leningrad Nuclear Power Plant named after Lenin.
The core of the RBMK-1000 reactor – a cylinder with a diameter of 11.8 and a height of 7 meters consists of a graphite masonry of neutron moderator. Fuel elements – TVELs, are placed in technological channels, which are surrounded with water as the coolant. For control and emergency protection, neutron absorbing rods are introduced. Side and end reflectors reflect up to 50% of neutrons leaving the core. This makes it possible not only to reduce the critical mass of nuclear fuel, but also to create uniform energy release over the entire volume.The steam mixture at a temperature of 284’C enters the drum separators, which separate the steam from water. The pressurised steam is directed to the turbines.
Operational experience has shown that such reactors are not limited to 1000MW. When the flow of water increased, heat withdrawal will increase and power of the channels can be increased by one and a half times. Exactly this was achieved in RBMK-1500 reactor without major changes to the construction and in the same reactor volume. The possibility to load fuel without stopping the reactor is an important advantage. A special machine with a guidance system is brought to the right channel with an accuracy of up to a millimeter and then, without human intervention, performs the necessary operations.
Fuel is loaded from a distance using this remote control. The second type is a water-water power reactor, abbreviated to VVER-1000. One of such reactors is installed at the Novovoronezh Nuclear Power Plant
named after the 50th anniversary of the USSR. Their introduction into the domestic power industry began at the end of the 70s. VVER-1000 is a reactor where water, regular water, serves both as a neutron moderator and a coolant. It is not difficult to notice that absence of graphite masonry
making such reactor more compact. The reactor itself is located in a steel vessel with diameter of 4,5 and height of 11 meters. And this is very important! Such reactors can be transported by rail.
All types of reactors are of the highest quality and their nuclear and radiation safety is a paramount.
All nuclear reactors are enclosed in reliable biological shields made of special types of steel and concrete. Reactors are equipped with highly reliable control, monitoring and protection systems that can bring them to a subcritical state within seconds. And, if necessary, the rapid cooling system is activated. The safety systems of Soviet nuclear power plants fully meet international requirements. And the real world experience of operation, which includes more than three thousand reactor-years, strengthens the confidence that safety is provided correctly. However, how much nuclear fuel will it take to operate nuclear power plants even if we consider that its required mass is incomparably lower than fossil fuels?
This is a good time to talk about a fast neutron reactor. In this reactor burning uranium turns it into new nuclear fuel. Since the reaction of fuel reproduction occurs only at fast neutrons, a moderator is not needed here, but intensive heat removal is needed. That is why in BN-600 reactor liquid sodium serves as a coolant and not water, which slows down neutrons. The active zone, pumps, intermediate heat exchangers and biological shield are located in the reactor vessel. The first circuit transmits heat to the intermediate second sodium circuit. And only in the third circuit, in the steam generator, to water. The Soviet Union has been and remains a pioneer in the use of atomic energy in new areas. After the launch of the first nuclear power plant, the world’s first nuclear-powered icebreaker Lenin the founder of the family of nuclear icebreakers, was built.
The CPSU program sets the task of accelerated development of nuclear energy. By the end of the twelfth five-year plan, its contribution to electricity production will be over twenty percent! But, when generating electricity, nuclear plants use only 30% of the energy of nuclear reactors, the rest of the heat is discharged.
The first steps to make more complete use of the nuclear energy in expensive facilities have already been taken. Since 1973, along with electricity, the Bilibino Nuclear Heat and Power Plant Plant has been producing heat. The heat of Beloyarsk, Kursk, Leningrad and Ignalina nuclear power plants
is used in households and manufacturing. Nuclear plants lifecycle includes heat supply. Another type of reactor, AST-500, is installed at such plants. This is a 500 megawatt water-supply reactor with natural coolant circulation. In the city of Shevchenko, the nuclear power plant, along with the production of electricity, desalinates Caspian water for industrial and domestic needs. The heat from nuclear reactors can be used in metallurgy, chemical industry, as well as in oil refining. Nuclear power can also contribute to food production programmes. Hot water obtained from nuclear power plants not only heats greenhouses.
It can be used to extract potassium chloride and manufacturing mineral fertilizers. Nuclear reactor heat can be used in various energy-intensive industries.
The development of nuclear energy has brought to life a new industry. At this modern enterprise, the Brezhnev Atommash Production Association, the casings of water-supply power reactors are made from high-strength materials. Nuclear energy, in comparison with the energy from fossil fuels, is much safer from the environmental perspective, since it doesn’t pollute the environment with the products of combustion. Data about the reactor operation and the state of air, water and soil are constantly displayed on the central control panel.
The Loviisa Nuclear Power Plant, built in Finland in cooperation with the the Soviet Union is considered by foreign experts to be among the cleanest stations in the world. Nuclear power plants constructed with the participation of the Soviet Union are now working in Bulgaria, Hungary, German Democratic Republic, Czechoslovakia and are being built in other brotherly countries. Construction of the second block of the Ignalina Nuclear Power Plant with the 1500 megawatt reactor is being completed, new reactors are coming into operation at Balakovskaya, Zaporizhzhya, and other nuclear power plants.
The Communist Party and the Soviet government pay close attention to nuclear power development. By the year 2000, electricity production at nuclear power plants will increase 5-7 times, compared with the end of the eleventh five-year period. The successful development of nuclear energy is one of the fundamental issues of further improvement of the efficiency of our national economy. The possession of nuclear energy for the benefit of man fills us with optimism and confidence that our home, the Earth will not be left without heat and light.