A boundary element–response matrix method for the multigroup criticality problems in the SP3 approximation

The 3D xyz multigroup BERM-SP3 transport method is here presented. This method, based on the simplified spherical harmonics approximation (SPN), with N = 3, and the assumption of linearly anisotropic scattering, makes use of a Response Matrix (RM) solution procedure, coupled with the Boundary Element Method (BEM), by which the SP3 partial differential equations are reduced to a system of boundary integral equations in terms of partial currents. Numerical problems, all endowed with a complete set of data and the reference results obtained by well assessed transport codes such as the discrete ordinate code TORT and the Monte Carlo code MCNP, illustrate the accuracy and efficiency of the method.