An Evaluation of Different Methods for Space-Dependent Resonance Shielding of Cross Sections in Fast Reactors

Within the framework of the Abajan, Bazazjantz, Bondarenko, and Nikolaev (ABBN) shielding factor approach, several methods have been proposed in the past for the treatment of resonance shielding of multigroup cross sections in heterogeneous cells of fast reactor lattices. First, the approximations made in the different methods and their interrelationship is briefly reviewed. Then, three recent efficient methods proposed by Bitelli et al., by Tone, and by Kujawski and Protsik are numerically compared by checking against exact fine-group collision probability calculations. It is found that the method of Bitelli et al. may give erroneous results, while the methods of Tone and of Kujawski and Protsik show satisfactory agreement with the exact calculations.