A Monte Carlo simulation model to determine the effective concrete materials for fast neutron shielding

Abstract

Concretes are popularly used as shielding materials in nuclear radiation facilities. Special concrete features are employed in the facilities where Fast neutrons, including corresponding ‘prompt gamma’ rays, are prevalent. The conventional shielding calculations for fast neutrons are complicated and constrained with energy-limited formulas. In this research work, a concrete bunker model has been developed with a variety of compositions and densities. Eleven following appropriate composite materials were used in this case; G4_C (2.3), Ordinary (2.5), Barytes BA-a (3.5), Magnetite M-a (3.55), Ilmenite I-Ia (3.5), Limonite with Steel Punch LS-a (4.54), (80%G4_C+20%Fe+10%B) Mix-1 (2.9), (80%G4_C+20%B4C) Mix-2 (2.35), (80%G4_C+20%BaSO4) Mix-3 (2.74), Serpentine (3) and Serpentine (3.3). Depth-dose profiles for each concrete composition were investigated by Monte Carlo simulation, subjected against an 18.5 MeV neutron source. Shielding properties, like Relaxation lengths, Half Value Layers, and Tenth Value Layers have been deduced harnessing these data. The most efficient materials for shielding fast neutrons regarding half value layers found for the two physics lists, QGSP_BERT_HP and Shielding, successively are, 5.78 and 12.48 cm for Serpentine (3.3), 14.88 and 9.18 cm for Ilmenite I-Ia (3.5), 14.28 and 25.18 cm for Limonite with Steel Punch LS-a (4.54), and 13.58 and 13.48 cm for (80%G4_C+20%Fe+10%B) Mix-1 (2.9). This model could be used to determine the radiation shielding parameters made of any kind of materials and composites using different sources of radiation.