The strength of a reactor subassembly duct depends on its cross section and its material properties. Straight- and curved-beam theories have been used to analyze ducts with elastic-perfectly-plastic material behavior, and this analysis has been found to be suitable and convenient for parametric studies. The strengths of hexcans with different corner radii have been compared, and the stiffening effect of increasing radius has been quantified. The relative strengths of different duct cross sections have also been determined.