Radiation shielding performance of metal oxides/EPDM rubber composites using Geant4 simulation and computational...

Area of Science:

• Materials Science
• Nuclear Engineering
• Radiation Physics

Background:

• Ethylene propylene diene monomer (EPDM) rubber is a versatile polymer.
• Effective radiation shielding materials are crucial for protecting workers in radiation facilities.
• Metal oxides offer potential for enhancing the shielding properties of polymer composites.

Purpose of the Study:

• To evaluate the gamma and neutron radiation shielding performance of EPDM rubber composites.
• To investigate the effect of incorporating different metal oxides (Al₂O₃, CuO, CdO, Gd₂O₃, Bi₂O₃) on shielding capabilities.
• To explore the suitability of these composites for protective clothing and gloves.

Main Methods:

• Geant4 Monte Carlo simulation toolkit was used to calculate gamma shielding parameters (μ, μ/ρ, MFP, HVL, TVL) from 0.015 to 15 MeV.
• XCOM software was employed for validation of simulated mass attenuation coefficients (μ/ρ).
• Macroscopic effective removal cross-section (Ʃ_R) for fast neutrons was calculated using MRCsC software.

Main Results:

• Gamma shielding performance increased in the order: EPDM < Al₂O₃/EPDM < CuO/EPDM < CdO/EPDM < Gd₂O₃/EPDM < Bi₂O₃/EPDM.
• Sudden increases in gamma shielding were observed at specific energies due to K absorption edges of Cd, Gd, and Bi.
• Al₂O₃/EPDM composites exhibited the highest fast neutron shielding (Ʃ_R), while pure EPDM showed the lowest.

Conclusions:

• The investigated metal oxide/EPDM rubber composites demonstrate significant potential as radiation protective materials.
• Bismuth oxide (Bi₂O₃) and Gadolinium oxide (Gd₂O₃) based composites are effective against gamma radiation.
• Aluminum oxide (Al₂O₃) based composites are effective against neutron radiation, suitable for comfortable clothing and gloves.