Preliminary analysis on the thermal-mechanical behavior of dispersed plate-type fuel under reactivity insertion accident

In this study, a modified two-dimensional geometry model was employed comprised of metal cladding, a metal matrix, and dispersed fuel particles. And an analysis method was established to simulate the thermal–mechanical behavior of dispersed plate-type fuel under the Reactivity Insertion Accident (RIA). Key fuel properties including thermal performance, mechanical behaviors and irradiation effects were considered. All these models were coded in the ABAQUS subroutines and solved. The influences of heat transfer deterioration, fission gas and burnup were investigated. Significant parameters to describe the performance of the fuel element, such as temperature, von Mises stress and strain profile, were evaluated. The results indicate that the deterioration of the heat transfer in the flow channel and the deepening burnup increase stress and strain of the dispersed plate-type fuel. The fission gas causes the crack of the fuel particles.