Study of efficiency of SN albedo boundary conditions for non-indented two non-multiplying regions around the active domain

We discuss and show in this paper the accuracy of approximate discrete ordinates (SN) albedo boundary conditions for one-speed SN eigenvalue problems in X,Y-geometry. The SN albedo matrix substitutes approximately the two non-multiplying regions, e.g., baffle-reflector system around the fuel regions, as we neglect the transverse leakage terms within the baffle and reflector regions. We show numerical results to a typical test problem to illustrate the efficiency by analyzing the accuracy of the numerical results versus the CPU time of each run. (author)