The DYN3D trigonal-geometry diffusion model – verification using the AER-FCM-101 benchmark

DYN3D is a three-dimensional nodal diffusion code for steady-state and transient analyses of light-water reactors with square and hexagonal fuel assembly geometries as well as of innovative reactor concepts, which is undergoing continuous development.
In this work, the trigonal-geometry DYN3D diffusion model is verified by means of the AER-FCM-101 benchmark. With increasing trigonal mesh refinement, both effective multiplication factor and power distribution converge well to the extrapolated finite-element reference solution. In addition, a comparison to the hexagonal DYN3D diffusion models HEXNEM1 and HEXNEM2 is given.