Abstract
In pressurized light water reactor fuel assemblies, spacer grids support nuclear fuel rods both laterally and vertically. The fuel rods are supported by spacer grid springs and grid dimples that are located in the grid cell. Supporting the fuel rods mainly relies on the characteristics of the spacer grid springs, which are closely related to the shape to the springs. To improve the characteristics of the springs, a structural optimization method is employed for the shape design of spacer grid springs using commercial codes. Design requirements are defined and a design process is established for the spacer grid springs. The design process includes mathematical optimization as well as a practical design methods. Shapes of the grid springs are optimized to have better performance.
