The Potential Application of Mining Wastes and Slag as Radiation Shielding: A Characterization Study Using EpiXS

The inclusion of nuclear energy in the Philippines' energy mix raises the prospect of the country developing a nuclear power program. More than ever, there is a need for a radioactive waste management system that includes a mechanism for disposing of radiation waste. In this study, Philippine mine wastes and mining byproducts (i.e., ferronickel slag, nickel mine waste, gold-mine tailings, and copper-mine tailings) are characterized for radiation shielding properties using the EPICS2017 library and interpolated by the EpiXS software for potential use as low-level radioactive waste (LLW) embankment. The mass attenuation coefficients (MAC) in the intermediate to high gamma energy range of 662–1332 keV were as follows: gold-mine tailings > ferronickel slag > copper-mine tailings > nickel mine wastes. Nickel mine wastes, when compared to other mining wastes, has the highest effective atomic number (Z_eff) and the highest effective electron density (N_eff), except for photon energies between 4 and 8 keV. The photoelectric predominance region has the lowest exposure buildup factors (EBF) and the Compton scattering predominance region has the greatest EBF. The MACs of ferronickel slag, gold- and copper-mine tailings are greater than some waste-based mortar and heavyweight concrete and comparable to slag- and fly ash-based geopolymers at intermediate to high gamma energies. Among the mine wastes taken into consideration, nickel wastes would typically be the best embankment material for LLW in terms of attenuating X-rays and gamma rays. It is comparable to Portland cement's radiation-shielding properties.