Monte Carlo Simulation and N-XCOM Software Calculation of the Neutron Shielding Parameters for the NCRP Report 144 Recommended Conventional Concretes

Abstract

Purpose: Radiation shielding requires deep knowledge about the shielding materials properties. Additionally, the interaction between the radiation and materials should be well understood.

Materials and Methods: Monte Carlo (MC) simulation, NXCOM, and WinXCOM computational programs were utilized for the concrete shielding properties against 1.5 MeV neutron beam and ¹³⁷Cs emitted γ-ray. In a simulated “good geometry” using MCNP5 MC code, NXCOM and WinXCOM, radiation attenuation factor (µ), microscopic neutron removal cross-section (  Half and Tenth Value Layers (HVL and TVL) of the studied concretes were derived. Obtained results by the methods were compared and discussed.

Results: For ¹³⁷Cs emitted γ-ray, mass attenuation factor (µ/ρ) obtained as 0.026 cm²/g, 0.025 cm²/g, and 0.025 cm²/g for the Serpentine concrete as the minimum factors by MCNP5 code, WinXCOM and NXCOM software, respectively. Good agreement was seen in the results derived by the use of the applied calculation methods. Maximum values for the µ/ρ were calculated as 0.03 cm²/g, 0.029 cm²/g and 0.029 cm²/g by MCNP5 code, WinXCOM and NXCOM, respectively. For the neutron attenuation factor, calculations were conducted for the concretes and the highest and lowest Σ_R/ρ were derived for Serpentine and Ordinary concretes. MCNP5 MC code was calculated Σ_R/ρ for the Serpentine and Ordinary concretes as 0.039 cm²/g and 0.030 cm²/g, respectively. Σ_R/ρ for the Serpentine and Ordinary concretes as 0.039 cm²/g and 0.030 cm²/g, respectively.

Conclusion: It was concluded that the calculated results showed N-XCOM program can be applied for the shielding calculations for the conventional concretes studied in this work.