Coarse-Mesh Method for Solving the Two-Group Neutron Diffusion Equation for PWRs (Pressurized Water Reactors) with Hexagonal Fuel Assemblies

摘要

A method for solving the static two-group neutron diffusion equation for pressurized water reactors (PWR) with large hexagonal fuel assemblies was developed. A method, similar to the coarse-mesh expansion method, and based on seven meshes and mesh-points per hexagonal-z node (SPPH method) was developed for the fast-neutron flux solution. A simplified version of the analytical nodal method is applied to the thermal-neutron flux solution. Comparison with fine-mesh finite-difference solutions shows that the SPPH method is adequate for predicting the assembly powers for PWR's with lattice pitch of 24 cm.