Energy progress is inextricably linked to the growth in demand for electricity, which, in turn, requires the search for new, more efficient and economically viable sources of energy. The limited resources of traditional fossil fuel and the desire to overcome the energy crisis have made nuclear power one of the priority areas for the development of the energy industry around the world. Today, nuclear power plants (nuclear power plants) have become an important element of the energy systems of developed countries.
Nuclear power plants have a lot in common with thermal power plants (TPPs). Both nuclear power plants and thermal power plants use the principle of converting thermal energy into electrical energy. The main steps in this process are as follows:
Despite the similar principle of operation, the main difference between nuclear and thermal power plants is the method of producing heat to heat water. Traditional thermal power plants use heat obtained by burning coal or gas fuel for this purpose. Nuclear power plants generate heat as a result of a controlled chain reaction of uranium fission, which makes this method more efficient and environmentally friendly.
Modern nuclear power plants are being built using advanced technologies that ensure their high reliability and safety. The basis of such stations is a light water nuclear reactor, which is used for efficient and safe production of electricity.
The principle of operation of a light water reactor
In light water reactors installed at nuclear power plants, water plays a key role in the power generation process. The reactor vessel houses the active zone and the first circuit. The water in the first circuit performs two important functions:
When water circulates through the primary circuit, it absorbs heat generated in the reactor core. This heat is then transferred to the secondary circuit via a heat exchanger, also known as a steam generator. This circuit generates steam, which is then used to rotate the turbine generator, where mechanical energy is converted into electrical energy.
Content: environmental protection
Another key element of a nuclear power plant is a containment (protective shell), a specially designed structure that surrounds the primary circuit and all its components, including pipelines. Container plays a critical role in ensuring safety: it isolates any radioactive products that may enter the first circuit water, preventing their release into the environment.
Economic aspects of nuclear reactors
The financial costs of equipment necessary for the operation of nuclear power plants account for a significant part of the total construction budget of the plant. About 90% of the cost of a nuclear power plant falls on the reactor vessel, heat exchangers, pumps, tanks and pipelines. These units must be designed and manufactured to ensure maximum economic efficiency, but without compromising reliability and durability.
Radiation has a multifaceted effect on steels and alloys, changing them mechanical properties and corrosion resistance. The increase in strength is accompanied by a loss of plasticity and viscosity, which makes materials more brittle. At the same time, water radiolysis enhances corrosion processes, destroying protective oxide films on metal surfaces. These factors must be taken into account when choosing materials for structures operating under high radiation loads to ensure their durability and safety.
Mechanical properties under the influence of radiation
The interaction of high-energy neutrons with atoms that make up crystal lattice metals, leads to radiation defects. When neutrons hit atoms, they transfer their energy to them, which leads to displacements in the lattice. The process is like playing billiards: one atom, when hit, displaces the others, creating a chain reaction of displacements.
At the same time, areas with a high concentration of vacancies (voids) are formed in the material structure, surrounded by zones with increased atomic density in the interstitial spaces. These changes lead to an increase in the strength of the metal, but at the same time reduce its viscosity and plasticity. As a result, the metal becomes more brittle, which can significantly limit its use in conditions that require high resistance to mechanical loads.
The effect of radiation on corrosion resistance
Corrosion resistance steels and alloys are significantly reduced when exposed to radiation. This is especially important for materials that work in contact with water and water vapor, which are used in nuclear power plant heat exchange systems. Irradiation causes radiolysis of water, which leads to the breakdown of water molecules into ions, oxygen atoms, hydrogen atoms and OH hydroxide ions—.
The resulting oxygen oxidizes the metal, and hydrogen causes it to hydrogenate, which further contributes to the embrittlement of the material. Under normal conditions, oxide films formed on the metal surface protect it from corrosion. However, radiolysis of water and an increase in the concentration of hydroxide ions contribute to the destruction of these films, which accelerates corrosion processes.
For aluminum alloys, for example, the rate of corrosion in an aqueous medium under the influence of radiation can increase by 2-3 times. Austenitic chromium-nickel steels used in wet steam conditions are subject to intergranular corrosion and corrosion cracking, which significantly reduces their performance characteristics.
Modern materials play a key role in ensuring radiation and corrosion resistance, which makes them irreplaceable in the nuclear power industry. One of the main materials for nuclear power plants is corrosion-resistant chromium-nickel steels, such as 12X18N9, 12X18H10T, 12X18N9SMR et 10X17N13M3T. They are resistant to radiation and aggressive environments, which extends the life of the equipment.
Nuclear power plants are used to weld the housings of working elements high-alloyed 08X19H10G2B, 10X18H25AM6, 04X19H11M3 and 07X25N13 steels. Their use makes it possible to reduce the cost of repairing and maintaining equipment.
The St. Petersburg Precision Alloy Plant offers proven and reliable solutions that meet the most stringent safety and efficiency requirements. We are proud of our contribution into the development of nuclear energy and we continue to work to improve our products et technologies. For cooperation questions, please contact phones or leave application on the site. Our experts will contact you and answer your questions in detail.
