Key problems on the mechanical behavior of nuclear materials and structures of pressured water reactors

Abstract

Nuclear energy is an important option to ensure the national energy safety. The mechanical behavior as well as the degradation of the mechanical behavior of nuclear materials under harsh environment of high temperature, intensive radiation and strong chemical corrosion directly affects the performance of the key components and structures, which finally determines the safety and the economy of nuclear reactors and power plants. However, due to the limited knowledge of the mechanical behavior of nuclear materials and structures under complex working conditions, many critical questions remain to be answered during the whole life cycle of a reactor which spans the stages of design, construction, maintenance and dismantlement of the reactor. To clarify the key problems on the studies of the mechanical behavior of nuclear materials and structures, the present papers firstly introduces the basis principles of radiation effects. Then according to the intensity of radiation and chemical corrosion, state of the art studies on the mechanical behavior of the fuels, the rector internal structures and the containment structure are respectively reviewed. Typical results on the constitutive models of the fuel materials, the stress corrosion crack models, the numerical modeling strategy for fluid-structure interaction problems as well as the design standards, are summarized and listed. Finally the challenges to further studies are analyzed and summarized. High-fidelity multi-scale modeling of the mechanical behavior of fuels and structural materials is the bottleneck for numerical studies and advanced irradiation techniques are the bottleneck for experimental studies.