The nuclear industry uses stainless steel in a variety of components: reactors, heat exchangers, turbines, radioactive sludge ponds, and more.
The components used, are generally made of stainless steel, a material that provides maximum corrosion resistance and a long reliability in time with little to no maintenance.
Stainless Steel Grades and Cobalt Restrictions for Nuclear Applications
Subject to the environment the most common grades are 1.4307 (304L) and especially 1.4404 (316L). Occasionally it happens that the application demands also for high austenitic grades or high yield grades like duplex stainless steel.
In addition, the stainless steel has often further restrictions with regards to the chemical composition. In particular the level of cobalt it contains, may have limitations. A general maximum level of 0.2 percent is acceptable, but it happens to have restrictions that go down to a maximum content of 0.05 percent. This is because this component contains an isotope that, when irradiated by nuclear materials, itself becomes radioactive and deteriorates.
The requested maximum amount of Cobalt has serious implications with the melt of the raw material itself. Stainless steel is recycled to 95% and more from scrap. The more stringent the Cobalt content limitations are, the lesser scrap can be used.
Meeting Strict Standards for Nuclear Stainless Steel Sections
Due to the nature of the application, the quality standards are among the strictest of all. Montanstahl has a long experience in handling production of sections and components for the nuclear industry.
Each project demands for its own specific requirements: a production plan is mutually agreed, defining each production step with relevant procedures, also the NDTs are specified and will be protocolled meticulously for the final documentation and will be included in the lifetime record.
Both the Quality Department and the Production Departments are trained and used to handle productions of profiles with augmented controls, inspections and related paperwork with hold points and witnessing points, third party inspections, that are demanded by the nuclear industry.
These sorts of products follow a dedicate way through production and are accompanied by a specifically appointed project manager. Of course, the colleagues from the quality department are always available for any requested support.
What technologies are used
Montanstahl is able to use all its available production technologies, choosing the most suitable for the purpose with the customer. The required profiles may be produced by hot rolling, hot extruding, or laser welding. In addition, there is the possibility to further tighten the products tolerances using a hot rolled, hot extruded or laser welded pre-shape and cold drawing it to the requested dimensions and tolerances.
Where stainless steel is used in the nuclear industry
Containment vessels are critical components in nuclear power plants, responsible for holding the reactor core and preventing the release of radioactive materials. These vessels must be able to withstand high pressures, temperatures, and radiation levels, which is why they’re constructed using materials that can withstand these extreme conditions. Stainless steel is the preferred material for constructing containment vessels in nuclear reactors because of its excellent strength, durability, and resistance to corrosion.
Piping systems are used in nuclear reactors to transport coolant, fuel, and other materials throughout the reactor. These piping systems must be able to withstand high pressures and temperatures, as well as the corrosive effects of radioactive materials. Stainless steel is the preferred material for piping systems in nuclear reactors because of its high resistance to corrosion.
Stainless steel piping systems are made using high-quality, corrosion-resistant stainless steel alloys, which are designed to withstand the harsh environments found in nuclear reactors. These alloys are resistant to pitting and crevice corrosion, which can occur due to the contact of materials with radioactive fluids. Stainless steel piping systems also help maintain the integrity of the system, preventing leaks and other issues that could lead to dangerous situations.
Fuel rods is the material that surrounds nuclear fuel pellets and is responsible for containing the fuel and protecting it from the reactor environment. The rods material must be strong, durable, and resistant to corrosion, radiation, and extreme temperatures. Stainless steel is used as a fuel rods material due to its excellent mechanical properties and corrosion resistance.
Stainless steel fuel rods helps maintain the integrity of the fuel, reducing the risk of a nuclear accident. The strength and durability of stainless steel also make it an ideal material for use in fuel rods, as it can withstand the extreme temperatures and pressures that occur in a nuclear reactor.
Stainless steel is also used in the construction of storage tanks for nuclear waste. Stainless steel is highly resistant to corrosion, making it an ideal material for storing radioactive waste, which can be highly corrosive. Stainless steel storage tanks help ensure that radioactive waste is safely contained and transported.
Beside from concrete, lots of structural load bearing parts are made using stainless steel structural sections like beams, channels, angle bars and hollow sections. This is valid both for the reactor core and all surrounding services, like fuel rod storage and preparation etcetera. Several structural sections are only available in welded execution and this leads the nuclear industry to additional safety and quality requirements for welded structural components.
In 2013 Sellafield Ltd. released a new issue of its specification: “Fabrication of Plant & Equipment (Carbon Steel & Stainless Steel) General Duty”, including laser beam welding as acceptable welding method. And today the laser welding technology is fully accepted for the production of sections and parts for the nuclear industry worldwide.
The Essential Role of Stainless Steel in Ensuring Safety and Reliability in the Nuclear Industry
In conclusion, stainless steel is an essential material in the nuclear industry due to its exceptional strength, durability, and resistance to extreme temperatures and radiation. Stainless steel is used in the construction of containment vessels, piping systems, fuel cladding, storage tanks and load bearing structures, all critical components of a nuclear reactor.
The use of stainless steel in the nuclear industry helps ensure the safety and reliability of nuclear reactors, preventing accidents and protecting the environment.
As the demand for clean, reliable energy sources continues to grow, the use of stainless steel in the nuclear industry is likely to increase, as it is an essential material that helps ensure the safe and efficient operation of nuclear power plants.
Montanstahl has supplied section for the nuclear industry in almost all relevant European Countries, plus the USA and China and is considered a reliable and competent partner for supplying stainless steel sections into the nuclear industry.