Factors Affecting Fuel Rod Burst in LOCA Safety Analysis

Rod internal pressure can be affected by many factors related to the fuel rod uncertainty. If ballooning and burst happens, there is a possibility that fragmented fuel pellet scan be dispersed into the core. In this paper, factors affecting fuel rod burst related to fuel uncertainty are evaluated and their combined effects are preliminarily assessed within licensing fuel burnup. Factors affecting fuel rod burst and their combined effects were evaluated. Following results can be drawn preliminarily. Maximum power was observed at 5-10 MWd/kgU burnup, and it reduced continuously with burnup increase. Manufacturing uncertainty showed a little or moderate influence on peak power for rod burst. But related to the model uncertainty, particularly heat transfer coefficient of coolant, fission gas release and clad yield stress showed significant impacts.