A new generation nuclear power plant. A new nuclear power plant in Russia

Over the past quarter-century, several generations have changed, not only in our society. Today, nuclear power plants of the new generation are being built. The newest Russian power units are now equipped with only water-cooled reactors of the generation 3+. Reactors of this type can be called without exaggeration the safest. During the entire operation of VVER reactors (water-water power reactor), there was not a single serious accident. Nuclear power plants of a new type in the world in total have already more than 1000 years of stable and accident-free operation.

The design and operation of the newest reactor 3+

Uranium fuel in the reactor is enclosed in zirconium tubes, the so-called fuel elements, or TVELs. They constitute the reactive zone of the reactor itself. When the absorption rods are removed from this zone, the flow of neutron particles increases in the reactor, and then a self-sustaining chain fission reaction begins. With this uranium bond, a large amount of energy is released, which heats the fuel elements. The plant equipped with VVER operates on a two-circuit scheme. First, pure water passes through the reactor, which was already purified from various impurities. Then it passes directly through the active zone, where it cools and bathes the fuel elements. Such water is heated, its temperature reaches 320 degrees Celsius, so that it remains in a liquid state, it must be kept at a pressure of 160 atmospheres! Then hot water should flow into the steam generator, giving off heat. And the second loop fluid then re-enters the reactor.

The following actions are in accordance with the usual CHP. The water in the second circuit in the steam generator naturally converts to steam, the gaseous state of the water rotates the turbine. This mechanism forces the electric generator to generate electric current. The reactor itself and the steam generator are located inside a sealed concrete shell. In the steam generator, the primary circuit water leaving the reactor does not interact in any way with the liquid from the second circuit going to the turbine. This scheme of the reactor and steam generator location excludes the penetration of radiation waste outside the reactor hall of the station.

On saving money

A new nuclear power plant in Russia requires 40% of the total cost of the station itself for the cost of security systems. The bulk of the funds are allocated to the automation and design of the power unit, as well as to the equipment of security systems.

The basis for ensuring safety in a new generation of nuclear power plants is the principle of defense in depth, based on the use of a system of four physical barriers to the release of radioactive substances.

The first barrier

It is presented in the form of the strength of the tablets with uranium fuel. After the so-called sintering process in an oven at a temperature of 1200 degrees, the tablets acquire high-strength dynamic properties. They do not collapse under the influence of high temperatures. They are placed in zirconium tubes, forming a shell of fuel elements. One such fuel element is injected automatically with more than 200 tablets. When they fill the zirconium tube completely, the robot introduces a spring that presses them to the point of failure. Then the machine picks out the air, and then completely seals it.

The second barrier

It is a hermetic enclosure of zirconium fuel elements. The shell of TVEL is made of zirconium of nuclear purity. It has increased corrosion resistance, it is able to keep the shape at a temperature of more than 1000 degrees. The quality control of the manufacture of nuclear fuel is carried out at all stages of its production. As a result of multistage quality checks, the possibility of depressurizing fuel elements is extremely low.

The third barrier

It is made in the form of a solid steel reactor body, the thickness of which is 20 cm. It is designed for working pressure of 160 atmospheres. The reactor body ensures the prevention of the release of fission products under the protective shell.

The Fourth Barrier

It is a sealed protective shell of the reactor hall itself, which has one more name - a confiscation. It consists of only two parts: the inner and outer shells. The outer shell provides protection from all external influences of both natural and technogenic nature. The thickness of the outer shell is 80 cm of high-strength concrete.

The inner shell with a concrete wall thickness is 1 meter 20 cm. It is covered with a solid steel 8 mm sheet. In addition, its screed is strengthened by special systems of cables stretched inside the shell itself. In other words, it is a cocoon made of steel, which pulls together concrete, reinforcing its strength three times.

Nuances of the protective coating

The internal protective shell of the new generation nuclear power plant withstands a pressure of 7 kilograms per square centimeter, as well as a high temperature of up to 200 degrees Celsius.

Between the inner and outer shells there is an intercomplex space. It has a system of filtering gases that come from the reactor compartment. The most powerful reinforced concrete shell retains its integrity at an earthquake of 8 points. Withstands the drop in the aircraft, the weight of which was calculated up to 200 tons, and also allows to withstand extreme external influences such as tornado and hurricanes, with a maximum wind speed of 56 meters per second, the probability of which is possible once in 10,000 years. And yet such a shell protects against an air shock wave with a pressure in the front up to 30 kPa.

The peculiarity of nuclear power generation 3+

A system of four physical barriers of defense in depth excludes radioactive releases from the power unit in the event of an emergency. In all VVER reactors there are passive and active safety systems, the combination of which guarantees the solution of three main tasks that arise in the event of an emergency:

• Stopping and stopping nuclear reactions;
• Ensuring the permanent removal of heat from nuclear fuel and the power unit itself;
• Prevention of the release of radionuclides beyond the confines in the event of an emergency.

VVER-1200 in Russia and in the world

The nuclear power plants of Japan's new generation after the accident at the Fukushima-1 nuclear power plant became safe. The Japanese then decided to no longer receive energy with the help of a peaceful atom. However, the new government returned to nuclear energy, as the country's economy suffered heavy losses. Domestic engineers with nuclear physicists began to develop a safe nuclear power plant of a new generation. In 2006, the world learned about the new super-powerful and safe development of domestic scientists.

In May 2016, a grand construction in the black earth region was completed and the successful completion of the testing of the 6th power unit at Novovoronezh NPP. The new system works stably and effectively! For the first time in the construction of the station, engineers designed only one and the highest cooling tower in the world. While previously built two cooling towers per power unit. Thanks to such developments, it was possible to save financial resources and save technology. Another year at the station will be carried out work of a different nature. This is necessary in order to gradually put into operation the remaining equipment, since it is impossible to start everything at once. Ahead of the Novovoronezh NPP - the construction of the 7th power unit, it will last two more years. After that, Voronezh will be the only region that has implemented such a large-scale project. Every year Voronezh is visited by various delegations that study the work of the nuclear power plant. Such domestic development left behind the West and East in the energy sector. Today, various states want to introduce, and some already use such nuclear power plants.

A new generation of reactors is working for the benefit of China in Tianwan. Today such stations are being built in India, Belarus, the Baltic States. In the Russian Federation, VVER-1200 is being introduced in Voronezh, the Leningrad Region. The plans are to build a similar structure in the energy sector in the Republic of Bangladesh and the Turkish state. In March 2017 it became known that the Czech Republic actively cooperates with Rosatom to build a similar station on its land. In Russia they plan to build a nuclear power plant (a new generation) in Seversk (Tomsk region), Nizhny Novgorod and Kursk.