Applicability of Albedo-Sn Transport Method to Analysis of Radiation Shielding Problem

摘要

Albedo-Sn method was developed to predict the angular flux near the coupling boundary in the bootstrap method, using the energy-and-angle dependent double differential albedo boundary condition. In order to verify the applicability of the method to the reactor shielding design, two types of shielding problem have been analyzed. First, the neutron skyshine dose rates measured at the YAYOI reactor in University of Tokyo are predicted within an accuracy of 20%. It is also found that the neutron spectrum in the air-over-ground is much affected by albedo reflection from the ground and is reproduced well by the albedo-Sn method. Second, as for the neutron streaming through a sodium pipe chase-way, the albedo-Sn calculation saves a computer time and gives the results which agree with those by the reference Sn calculation.