A comparative investigation on mechanical, gamma-ray and neutron shielding properties of some iron and boron containing concretes samples for nuclear safety applications

Abstract

This study explores the gamma-ray and neutron shielding properties of fourteen different concrete samples, each tailored with varying percentages of Boron Carbide, Iron, and Iron Boride. Using the MCNP 6.3 Monte Carlo code, we calculated transmission factors for photon energies of 0.662 MeV, 1.1732 MeV, and 1.3325 MeV, and analyzed the impact of concrete thickness on shielding efficacy. Additionally, the Phy-X/PSD software was used to compute critical parameters such as linear and mass attenuation coefficients, half-value layer, tenth-value layer, mean free path, and fast neutron removal cross-section to gain a comprehensive understanding of each material's shielding capabilities. Our findings indicate that adding iron to the concrete matrix significantly enhances its attenuation properties, with the 20%Fe+80%Concrete sample outperforming all others. This composition demonstrated the lowest transmission factors across all tested energies and thicknesses, indicating superior photon attenuation. Moreover, the 20%Fe+80% Concrete exhibited the highest fast neutron removal cross-section, making it highly effective for environments requiring neutron shielding. In addition to the shielding properties, we analyzed the Elastic (Young's) Modulus of the concrete samples to understand their mechanical properties. Standard Concrete had an Elastic Modulus of 261.24 GPa, while the introduction of boron carbide significantly enhanced the Elastic Modulus, with pure boron carbide concrete exhibiting a value of 518.88 GPa. Concrete samples with varying percentages of boron carbide (5%, 10%, 15%, and 20%) showed a progressive increase in Elastic Modulus, indicating that higher proportions of boron carbide consistently enhance the material's stiffness. Conversely, concrete samples with iron boride and iron showed slight reductions in Elastic Modulus. It can be concluded that the boron carbide enhances stiffness, iron and iron boride provide a balance between stiffness and other properties. In conclusion, the 20%Fe+80%Concrete is a standout material that could greatly improve radiation shielding, offering major benefits.