Impact analysis and test on the spacer grid assembly for PWRs

A spacer grid assembly is one of the main structural components of the fuel assemblies of pressurized light water reactors. The spacer grid assembly is structurally required to have enough buckling strength under various kinds of lateral loads acting on the fuel assembly so as to keep the fuel assembly straight. The structural performance of the spacer grid assembly is characterized in terms of its dynamic crush strength, which is usually acquired from the test. In this study, a dynamic buckling test and a finite element analysis on the KAERI designed spacer grid assembly are carried out. The pendulum-type tester was used in the test. In the finite element analysis, we proposed an analysis methodology that could predict the dynamic failure behavior of the spacer grid assembly using a commercial finite element code ABAQUS/explicit with appropriate boundary conditions. As a result of the comparisons, the analysis result is in good agreement with the test result to within a 10% difference range. Therefore, we could predict the dynamic behaviors of a spacer grid assembly in advance before performing the dynamic buckling test. (orig.)