Design of a Spacer Grid Using Axiomatic Design

Recently, much attention has been focused on the design of the fuel assemblies in the Pressurized Light Water Reactor (PLWR). The spacer grid is one of the main structural components in a fuel assembly. It supports fuel rods, guides cooling water, and maintains geometry from the external impact loads. In this research, a new shape of the spacer grid is designed by the axiomatic approach. The Independence Axiom is utilized for the design. For the conceptual design, functional requirements (FRs) are defined and corresponding design parameters (DPs) are found to satisfy FRs in sequence. Overall configuration and shapes are determined in this process. Detailed design is carried out based on the result of the axiomatic design. For the detailed design, the system performances are evaluated by using linear and nonlinear finite element analysis. The dimensions are determined by optimization. Some commercial codes are utilized for the analysis and design.