NPP of a new generation. New NPP in Russia

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

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

Design and operation of the latest reactor 3+

Uranium fuel in the reactor is enclosed in zirconium tubes, the so-called fuel elements, or fuel rods. They make up the reactive zone of the reactor itself. When the absorption rods are removed from this zone, the flux of neutron particles increases in the reactor, and then a self-sustaining fission chain reaction begins. With this connection of uranium, a lot of energy is released, which heats up the fuel rods. Nuclear power plants equipped with VVER operate according to a two-loop scheme. First, pure water passes through the reactor, which was supplied already purified from various impurities. Then it passes directly through the core, where it cools and washes the fuel rods. This water is heatedits temperature reaches 320 degrees Celsius, in order for it to remain in a liquid state, it must be kept under a pressure of 160 atmospheres! Then hot water goes to the steam generator, giving off heat. And the secondary fluid then re-enters the reactor.

The following actions are in accordance with the CHP we are used to. The water in the secondary circuit naturally turns into steam in the steam generator, the gaseous state of the water rotates the turbine. This mechanism causes an electric generator to move, which produces an electric current. The reactor itself and the steam generator are located inside a sealed concrete shell. In the steam generator, the water from the primary circuit leaving the reactor does not interact in any way with the liquid from the secondary circuit going to the turbine. This scheme of operation of the reactor and steam generator arrangement 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 plant itself for the cost of safety systems. The main share of the funds is allocated for the automation and design of the power unit, as well as for the equipment of security systems.

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

First Barrier

It is presented in the form of the strength of the uranium fuel pellets themselves. After the so-called furnace sintering processat a temperature of 1200 degrees, the tablets acquire high-strength dynamic properties. They do not break down under the influence of high temperatures. They are placed in zirconium tubes that form the shell of the fuel elements. More than 200 pellets are automatically injected into one such fuel element. When they fill the zirconium tube completely, the automatic robot introduces a spring that presses them to failure. Then the machine pumps out the air, and then completely seals it.

Second barrier

Represents the tightness of the zirconium cladding fuel elements. The TVEL cladding is made of nuclear grade zirconium. It has increased corrosion resistance, is able to retain its shape at temperatures over 1000 degrees. Quality control of nuclear fuel manufacturing is carried out at all stages of its production. As a result of multi-stage quality checks, the possibility of depressurization of fuel elements is extremely low.

Third Barrier

It is made in the form of a durable steel reactor vessel, the thickness of which is 20 cm. It is designed for a working pressure of 160 atmospheres. The reactor pressure vessel prevents the release of fission products under the containment.

The fourth barrier

This is a sealed containment of the reactor hall itself, which has another name - containment. It consists of only two parts: the inner and outer shells. The outer shell provides protection from all external influences, both natural and man-made. Thicknessouter shell - 80 cm high-strength concrete.

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

The nuances of the protective coating

The inner containment of a new generation nuclear power plant can withstand a pressure of 7 kilograms per square centimeter, as well as high temperatures up to 200 degrees Celsius.

There is an inter-shell space between the inner and outer shells. It has a system for filtering gases that enter from the reactor compartment. The most powerful reinforced concrete shell maintains tightness during an earthquake of 8 points. Withstands the fall of an aircraft, the weight of which is calculated up to 200 tons, and also allows you to withstand extreme external influences, such as tornadoes and hurricanes, with a maximum wind speed of 56 meters per second, the probability of which is possible once in 10,000 years. Moreover, such a shell protects against an air shock wave with a front pressure of up to 30 kPa.

Feature of Generation 3 NPP+

A system of four physical barriers in defense in depth prevents radioactive releases outside the power unit in case of emergency. All VVER reactors have passive and active safety systems, the combination of which guarantees the solution of three main tasks,emergencies:

• stopping and stopping nuclear reactions;
• ensuring constant heat removal from nuclear fuel and the power unit itself;
• prevention of release of radionuclides outside the containment in case of emergencies.

VVER-1200 in Russia and worldwide

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

In May 2016, a grandiose construction project was completed in the black earth region and the testing of the 6th power unit at the Novovoronezh NPP was successfully completed. The new system works stably and efficiently! For the first time, during the construction of the station, engineers designed only one and the world's highest cooling tower for cooling water. While previously two cooling towers were built for one power unit. Thanks to such developments, it was possible to save money and save technology. For another year, various works will be carried out at the station. This is necessary in order to gradually commission the remaining equipment, since it is impossible to start everything at once. Ahead of the Novovoronezh NPP is the construction of the 7th power unit, it will last another two years. ThereafterVoronezh will be the only region that has implemented such a large-scale project. Every year Voronezh is visited by various delegations studying the operation of the nuclear power plant. Such domestic development has left behind the West and the East in the field of energy. 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, and the B altic states. In the Russian Federation, VVER-1200 is being introduced in Voronezh, Leningrad Region. The plans are to build a similar facility in the energy sector in the Republic of Bangladesh and the Turkish state. In March 2017, it became known that the Czech Republic was actively cooperating with Rosatom to build the same station on its soil. Russia plans to build nuclear power plants (new generation) in Seversk (Tomsk region), Nizhny Novgorod and Kursk.