Nuclear reactor fuel element failure analysis method based on meshless method

Abstract

A nuclear reactor fuel element failure analysis method based on a meshless method comprises the following steps of: 1, establishing a particle geometric model, and initializing particle parameters; 2, updating adjacent point particles, and calculating a weighting function and particle number density; 3, calculating energy conservation, and updating enthalpy values, temperatures and phase states of particles; 4, performing eutectic reaction calculation, updating the content and the physical property of particles, and updating the enthalpy value, the temperature and the phase state of the particles; 6, calculating the gravity, viscosity and surface tension of the fluid, and estimating the speed and position of fluid particles; 7, calculating solid motion, and updating the speed and position of solid particles; 8, correcting viscosity, and updating the speed and the position of fluid particles; 9, updating the load of the fluid on the solid; and 10, outputting data. According to the method, all phenomena in a nuclear reactor fuel element failure process are considered; on the basis of a meshless method, interface changes can be accurately captured, and compared with a grid method, the problem of grid distortion in large deformation is avoided; and the algorithm process is easy to realize large-scale parallel computing.

Description

technical field [0001] The invention relates to the technical field of research on failure behavior of core fuel in severe accidents of nuclear power plants, in particular to a failure analysis method for nuclear reactor fuel elements based on a gridless method. Background technique [0002] In severe accidents of nuclear reactors, if the core heat cannot be dissipated normally, the temperature of fuel elements and core structural materials will gradually increase. As the temperature rises, a series of reactions take place inside the nuclear reactor, causing the fuel elements to fail. In the early stage of a severe accident, the increase in temperature causes thermal expansion of the core material, and local deformation produces local stress. When the stress exceeds the yield stress of the corresponding material, the core material may fracture. Moreover, under the condition of high neutron radiation in the core, the possibility of brittle fracture of the core material is gr...

AI Technical Summary

Problems solved by technology

However, due to the solid deformation, fluid motion, and interaction between fluid and solid involved in the core failure process, grid distortion may occur when using the grid method, and it is difficult to consider the complex eutectic mass transfer in the grid method and chemical reaction process

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