Fuel cladding and fuel component

Abstract

The invention discloses a fuel cladding and a fuel component; the fuel cladding includes a zirconium alloy base, an intermediate layer arranged on the zirconium alloy base and having nonstoichiometryand gradient characteristics, and an ambient shielding layer arranged on the intermediate layer; the intermediate layer and the ambient shielding layer form a gradient composite coating of nonstoichiometry on the zirconium alloy base. The fuel cladding and the fuel component have the advantages that the problem that a traditional zirconium alloy cladding with single coating experiences interfacialstress and interfacial diffusion and zero tolerance to high temperature vapor oxidation is solved; through synergic design and the gradient composite coating of nonstoichiometry in the fuel cladding,the fuel cladding is applicable to accident fault-tolerant nuclear fuel claddings, and anti-accident ability of a nuclear reactor to maintain nuclear fuel component structure and functional integrality under severe conditions and its safety threshold are greatly increased.

Description

technical field [0001] The invention relates to the technical field of nuclear reactors, in particular to a fuel cladding and a fuel assembly. Background technique [0002] After some nuclear accidents, nuclear power safety has once again become the focus of international public attention, and how to further improve nuclear power safety, especially how to increase the safety threshold of nuclear reactors against nuclear accidents beyond the design basis, has also become an important issue for the sustainable development of nuclear energy. Accident Tolerant Fuels (ATF), a new concept of nuclear safety technology, was born under this background, and has gradually become one of the most important research topics in the world's nuclear power industry. The uranium dioxide fuel system is improved, upgraded or even fully replaced to reduce the reaction enthalpy and hydrogen generation of the cladding and high-temperature water vapor, improve the structural integrity and functionali...

AI Technical Summary

Problems solved by technology

Although the oxide film (ZrO 2 ) can improve the corrosion resistance of zirconium alloys, but ZrO 2 It is a thermal barrier material (the thermal conductivity is only 1.8-3.0W / mK), which will seriously hinder the heat exchange efficiency between the core and the coolant

In addition, ZrO 2 There is phase change cracking, and the oxidation goes deep into the zirconium matrix along the cracks, making the surface modification invalid

[0005] Germany's Siemens applied for a patent on the surface coating of fuel cladding in 1987. The types of coatings include TiC, TiN, ZrN, CrC, TiAlVN, TaN, ZrC and WC. The patent mainly considers wear resistance and normal work. The hydrothermal corrosion performance under the condition of water loss, did not take into account the high temperature steam oxidation performance under the condition of dehydration accident, the high temperature steam oxidation performance of these coating systems is poor

[0006] In summary, the current research on the surface modification of zirconium alloys is still limited to hydrothermal corrosion, hydrogen absorption, wear resistance, etc., and does not comprehensively consider accident conditions (such as high temperature of 1200 °C caused by dehydration accidents), heat exchange, etc. Efficiency, radiation resistance, and matching of coatings and zirconium alloy substrates (such as lattice matching, thermal conductivity matching, thermal expansion matching, etc.)

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