The influence of the mechanical properties on fuel rod support characteristics - A case study of dual cooled fuel

This paper concerns a finite element analysis for a spacer grid support (spring and dimple) design. An accurate prediction of the support characteristics (contact force vs. deflection) is the most crucial in the design by analysis. It is found that the mechanical properties are the key parameter to simulate the characteristics as close as the experimental results after using three different sets of mechanical property data including the actual tensile test results of the present material for a spacer grid of a dual cooled fuel. Besides, the validity of using the characteristics during unloading process is also discussed incorporating a possible overshoot of the support. The coincidence between the present finite element prediction and experimental results is quite good: less than 3.09% at most.