Abstract
Spacer grid which is one of the most important structural components in a pressurized light water reactor fuel assembly supports the fuel rods laterally and vertically. Based on design experiences and by scrutinizing the design features of foreign advanced nuclear fuels and the foreign patents of spacer grids, KAERI has devised its own spacer grid shapes and has acquired patents. In this study, a performance evaluation of two new spacer grid shapes devised by KAERI was carried out from the mechanical/structural and thermo hydraulic view points. And also performance evaluation of two commercial spacer grid shapes was carried out for the sake of a comparison. The comparisons included the spring characteristics, fuel rod vibration characteristics, fretting wear resistance, impact strength characteristics, CHF enhancement, and the pressure drop of the spacer grid shapes. The comparison results have shown that the performances of the new spacer grid shapes are better or at least not worse than those of the commercial spacer grid shapes.
