Calculation and Analysis of Multiscale Coupling of Dispersion Plate-type Fuel

The multi-scale characteristics of two-phase dispersion materials in dispersion-type plate fuel pose challenges to its performance research. To accurately analyze and evaluate the in-pile performance of U₃Si₂/Al dispersion-type plate fuel, based on the existing equivalent physical properties and behavior model of U₃Si₂/Al dispersion fuel meat, the creep attenuation coefficient model was established to accurately simulate the creep behavior of two-phase composites, particularly focusing on the complex creep characteristics of the equivalent fuel meat. Additionally, a three-dimensional macroscopic fuel plate model and a one-dimensional sphere model were constructed, and a multi-scale coupling method was proposed to couple these models, enabling simultaneous simulation at both scales. Based on the multi-scale multi-physics coupling analysis tool, the multi-physical field analysis of U₃Si₂/Al dispersion-type fuel was conducted, and the impact of fuel particle size and volume fraction was evaluated. The results inidcate that increasing the particle size and volume fraction only slightly increases the central temperature of the fuel; however, when the volume fraction increases from 30% to 40%, the fuel particle stress increases by 11.6%.