The vacuum in the nuclear industry
The nuclear industry
Vacuum equipment is widely used in the nuclear industry for a variety of applications, including the manufacture of equipment for the nuclear power sector, scientific research, radioactive waste handling, and the treatment and disposal of nuclear waste.
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■ Production
Vacuum melting reduces the content of dissolved gases and non-metallic inclusions, thereby improving the physical and mechanical properties of metals used in the nuclear industry. Typical applications include:
- Vacuum induction melting for the production of specialty alloys and stainless steels required for nuclear reactors. Processing under vacuum eliminates the risk of oxidation and prevents contamination of the molten metal by impurities such as oxygen, nitrogen, and hydrogen.
- Degassing of boron carbide pellets used in reactor control rods to absorb excess neutrons. The pellets are vacuum-degassed and then sealed in specially designed glass tubes to maintain the vacuum until further processing.
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■ Researches
- Vacuum chambers for isotope separation systems.
- Vacuum systems for nuclear reactor fuel unloading operations.
- Vacuum testing of equipment, including testing under vacuum conditions using vacuum degassing systems and helium leak detectors to verify structural integrity and leak-tightness.
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■ Control
Vacuum chambers for weld inspection are used to examine butt, fillet, T-joint, lap, and other types of welded joints. Through-thickness defects are identified by the behavior of the indicator solution beneath the chamber frame, where the formation of bubbles indicates the presence of a leak path. Helium mass spectrometer leak detectors enable the detection of both localized leaks and total leakage rates in pressure vessels, process equipment, and nuclear fuel elements, ensuring their integrity and leak-tightness.
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■ Disposal
Vacuum drying is used to prepare containers holding spent nuclear fuel for long-term storage. The pressure inside the container is reduced by evacuating the vapor-gas atmosphere from its internal cavity. As the pressure decreases, the saturation temperature of water is lowered, causing the residual water to boil off gradually and be removed as water vapor. The drying process must be fully automated and carried out in hermetically sealed equipment, eliminating the need for direct personnel involvement in radiation-controlled areas.
Vacuum Drying Technologies for Nuclear Waste
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■ Vacuum drying technology for spent ion-exchange resins, enabling drying at a temperature of 70°C, the use of a rotating separation cone made of perforated stainless steel to ensure uniform dewatering, and vacuum evacuation down to 0.1 bar.
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■ Technology for preparing spent nuclear fuel (SNF) containers for long-term storage. The process is carried out by reducing the pressure inside the container through evacuation of the vapor-gas atmosphere from its internal cavity. As the pressure decreases, the saturation temperature of water is lowered, causing the residual water to boil off gradually and be removed as water vapor.
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■ Vacuum drying technology for CASTOR® casks used for the dry storage of spent nuclear fuel. The process consists of two vacuum evacuation stages: preliminary drying and final evacuation for long-term storage. In some cases, helium is backfilled into the cask to accelerate the drying process and reduce residual moisture.
Advantages of Using Vacuum Equipment in the Nuclear Industry
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■ Improved material quality. Vacuum melting produces homogeneous, high-purity materials with superior mechanical properties. The absence of oxide inclusions ensures a more uniform stress distribution, delaying the initiation and propagation of microcracks.
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■ Reduced turbine exhaust pressure. Lowering the pressure at the turbine exhaust allows the maximum amount of thermal energy from steam to be converted into mechanical energy, thereby improving the overall efficiency of the power plant.
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■ Reliable equipment sealing. Because ionizing radiation poses significant risks to personnel and the environment, maintaining the leak-tightness of nuclear equipment throughout all stages of manufacturing and operation is essential. Vacuum pumps of various configurations are used to support sealing and leak-testing processes.
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■ Leak detection. Vacuum leak testing of nuclear power equipment helps prevent the release of radioactive materials. Helium mass spectrometer leak detectors and vacuum suction probes are used to identify and locate even the smallest leaks.
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■ Energy savings. Vacuum drying systems achieve high energy efficiency by repeatedly utilizing the heat supplied by fresh steam for water evaporation, thereby reducing overall energy consumption.
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■ Air removal from condensers. Vacuum systems continuously remove air and other non-condensable gases from condensers, preventing air pockets, ensuring the required cooling performance, and maximizing the efficiency of the steam cycle.
Suitable vacuum equipment
JSC Vacuummash (VACMA) designs and manufactures a wide range of vacuum equipment for industrial applications.
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■ Vacuum pumps and pumping systems, vacuum valves, and gate valves for a variety of applications in the nuclear industry.
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■ To select the most suitable equipment and receive a quotation based on your specific process requirements, please contact us using the details provided on our website.
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■ Our specialists will help you choose the optimum vacuum equipment, while our engineering team will develop a customized technical solution tailored to your specific application and operational requirements.
➜ The experts at JSC Vacuummash (VACMA) will help you select the optimum vacuum equipment—direct from the manufacturer at competitive prices.
➜ Browse the Vacuum Equipment Catalog on the Official VACMA.RU Website
+7 (843) 278-35-27 kazan@vacma.ru JSC Vacuummash (Vacma) plant: 58 Tulskaya St., Kazan, 420054, Russian Federation