Evaluation of neutron shielding performance for some alloys

Abstract

Alloys, in general, and stainless steel, in particular, are among the basic materials for shielding against nuclear radiation. Some selected alloys among a lot of shielding materials in numerous literature were investigated as shielding materials against neutrons in a wide neutron energy range of 10−5 eV to 20 MeV. The neutron mass attenuation coefficient (NMAC) for the materials under investigation was calculated using the Monte Carlo N-Particle transport code, version 5 (MCNP5). The results indicate that the alloys under investigation have a good shielding performance against neutrons along the studied neutron energy range especially 5% B4C (S8) alloy. The 5% B4C sample shows a high shielding performance for neutrons of energy < 1.6 x 10-3 MeV as compared to the other investigated alloys. While the stainless steel 316 (S3) shows the best shielding performance for neutrons of energies > 0.2 MeV. The study also shows that the alloy must contain a percentage of a light element that has a high ability to absorb slow neutrons such as boron. This study is useful in selecting the appropriate shielding material for specific neutron energies. MCNP5 calculations were confirmed by comparing its results for iron with the corresponding evaluated data ENDF/B-V extracted from International Atomic Energy Agency (IAEA) database.