MEASURED AND CALCULATED NEUTRON ALBEDO FOR CONCRETE AND IRON.

Abstract

Albedos were experimentally determined for a spectrum of fast fission neutrons incident on a 24- multiplied by 24- multiplied by 9-in. concrete slab and a 24- multiplied by 24- multiplied by 6-in. cold-rolled steel slab. The experimental dose albedos were compared with those from Oak Ridge National Laboratory (ORNL) 05R Monte Carlo calculations and with orders-of-scattering calculations performed using readily available multigroup cross sections. In general, the orders-of-scattering calculated reflected spectra compared well with the experimental fast-neutron reflection spectra. Discrepancies arise in the orders-of-scattering calculated results at particular energies and scattering angles due to deficiencies identified in the multigroup compilations. These results are relevant to reactor shieldings.