Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Features of Purification and Control of Sodium-Potassium Eutectic Alloy

6/05/2024 2024 - #02 Chemistry, physics and technology of reactor coolants

Ulyanov V.V. Koshelev M.M. Kremleva V.S. Bragin D.S. Prikazchikova A.A.

DOI: https://doi.org/10.26583/npe.2024.2.11

UDC: 621.039

Sodium-potassium is used mainly in low-power nuclear power plants, including space nuclear power plants. When choosing a coolant for such nuclear power plants, it is not cost considerations that come to the fore, but the safety, pre-operational storage, transportation and launch of installations filled with coolant. Justification for the use of a certain coolant in space nuclear power plants requires a thorough study of their physical and chemical properties, the type and form of impurities existing in it, the method of maintaining their quality, etc. In connection with the emergence of new promising areas for the use of alkali metal melts, for example, as working fluids in pressure measurement sensors, in high-temperature heat pipes and other equipment that does not allow periodic cleaning, justification of methods for thorough pre-cleaning is required to ensure a long service life. Molten alkali metals contain a variety of impurities, the amount of which depends on the specific operating conditions of the liquid metal circuit. Such sources of impurities are known as impurities entering the source metal loaded into the circuit, impurities in inert gases, oxide films on the internal surfaces of structural materials and diffusion of gases through the walls during operation. In circulation circuits, there is a continuous outflow of steel components into the cold zone, which leads to increased corrosion. Oxygen, which has high solubility in alkali metals, has the most adverse effect on the corrosion of structural materials. This article provides data on methods and means of controlling impurities in the circuit and methods for cleaning the alloy from them. Cleaning can be done using various methods; a distinction is made between preliminary and contour cleaning. The choice of purification method directly depends on the form of existence of impurities. Monitoring the purity of liquid metal coolants is necessary to perform two tasks. The first is the detection of emergency situations, such as depressurization of the circuit accompanied by a rapid increase in the content of impurities in the alloy and prevention of the consequences of decompaction (insoluble sediment in cold zones, blockage of pipelines, deterioration of thermal characteristics, etc.). The second task is to control slowly developing processes, such as corrosion of structural materials.


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eutectic sodium-potassium coolant purification control

Link for citing the article: Ulyanov V.V., Koshelev M.M., Kremleva V.S., Bragin D.S., Prikazchikova A.A. Features of Purification and Control of Sodium-Potassium Eutectic Alloy. Izvestiya vuzov. Yadernaya Energetika. 2024, no. 2, pp. 127-137; DOI: https://doi.org/10.26583/npe.2024.2.11 (in Russian).