Monte Carlo Calculations, Using the Albedo Concept, of the Fast-Neutron Dose Rates along the Center Lines of One- and Two-Legged Square Concrete Open Ducts and Comparison with Experiment

Monte Carlo calculations have been carried out to determine the fast-neutron dose-rate distributions along the center lines of both a straight and a two-legged square concrete duct for a particularly demanding source geometry. The calculations incorporated doubly differential dose-albedo data for concrete which were previously reported. A comparison of the results of the calculations with those from a geometrically similar experiment shows good agreement, and places on a firm foundation the concept of treating the fast-neutron duct transmission problem as a reflection phenomenon at a point that is describable by the differential albedo properties of the walls.