Gain from a Mixed Finite-Difference Formulation for Three-Dimensional Diffusion-Theory Neutronics

摘要

The advantage of a mixed differencing scheme for representing the diffusion theory approximation to neutron transport in three-dimensional triangular-Z geometry is demonstrated for a fast reactor. Most of the early codes employed the mesh edge difference formulation as is used in the German D3E code. A mesh centered formulation was chosen for use on a routine basis with mesh points located at the centers of the finite difference elements instead of at the corners where the internal material interfaces intersect, the VENURE code being the latest to use this scheme. Results are presented for a fast reactor core problem modeling hexagonal assemblies.