Nuclear reactor fuel early deformation analysis method based on particle method

Abstract

A nuclear reactor fuel early deformation analysis method based on a particle method mainly comprises the following steps: 1, establishing a geometric model, and setting particle physical property and mechanical parameters; 2, establishing a particle neighborhood domain; 3, calculating a solid boundary particle external force load based on boundary conditions and a solid collision model; 4, calculating temperature and calculating thermal expansion strain based on a thermal expansion model; 5, calculating plastic strain and elastic stress strain of the continuous medium particles in the solid based on the elastic model, the elastic-plastic model and the plastic model; 6, judging whether breakage occurs or not and updating the speed and the position of the particles; and 7, outputting a calculation result. The method can be used for analyzing the fuel early deformation behavior of the nuclear reactor in a serious accident; based on a particle method, the problem of grid distortion in a grid method can be effectively avoided; and the method is a pure Lagrange kernel method, and can effectively avoid tensile instability in the stress-strain analysis process.

Description

technical field [0001] The invention relates to the technical field of research on early deformation of fuel under severe nuclear reactor accidents, in particular to a method for analyzing early deformation of nuclear reactor fuel based on a particle method. Background technique [0002] When an accident occurs in a nuclear power plant, if the nuclear reactor core is not sufficiently cooled, the state of the fuel will deviate from the normal operating conditions, and its temperature rise will cause thermal expansion of the core structural materials and fuel, which will cause the overall deformation of the fuel and withstand additional of stress. The deformation of the fuel changes the shape and flow area of ​​the coolant channel, which affects the effect of subsequent emergency cooling measures. Moreover, measures such as the injection of emergency water will generate external force loads on the core structure and fuel. In this case, the fuel at high temperature is easily d...

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Problems solved by technology

In the field of marine research, the particle method has been successfully applied to the study of the interaction between elastic structural materials and ocean waves, but there are few studies on the application of complex situations in severe accidents in nuclear reactors

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