Analysis of Finite Element Simulation of Crack Initiation in Dispersion Fuel Particle

With the finite element method, the mutli-bubble fuel particle model was established and the stress distribution of the fuel particle was analyzed under the pressure of the fission gas bubbles (FGBs). The effect of the bubble location on the max tensile stress was summarized at the inner-border of bubble. And the crack initial location was found out while associated with the annealing result of the irradiated dispersion fuel particle. The results show that when the dispersion fuel particle suffers the pressure of the mutli-FGBs, the radius stress at the inner-border of bubble is the compress stress and the circular stress is the tensile stress. The farther the bubble location is relative to the center of the fuel particle, the bigger the max circular tensile stress is at the inner-border of bubble. The max circular tensile stress at the inner-border of the external bubble is much bigger than the central bubble’s. The crack of the dispersion fuel particle initiates at the inner-border of the external bubble.