Stress Analysis of the Lower Core Plate Subjected to Radiation-Induced Heat Generation

The Lower Core Plate (LCP) is a perforated circular plate that supports and positions the fuel assemblies. The plate contains numerous holes to allow flow through the plate and provide flow to each fuel assembly. The plate is bolted at the periphery to a ring welded to the inside diameter of the core barrel. The center span of the plate is supported by the lower support columns which are attached at the lower end of the lower support plate. Temperature differences between components of the lower support assembly induce significant thermal stresses in the LCP. In addition, due to the LCP's proximity to the core, radiation-induced heat generation cause a significant temperature increase in this component. Stress analysis has been performed to evaluate structural integrity and the results are presented. Since the LCP has several small features, a technique referred to as submodeling is used to determine the stresses