Assessment of radiological impact on the surrounding environment and biota for phosphogypsum waste stockyard in Korean facility

Abstract

In this study, the effects of deposited gypsum residues on the surrounding environment and radiation exposure in plants and animals were evaluated under various exposure situations. A waste stockyard in a Korean facility (surrounded by mountains and sea) was used to store phosphogypsum, a byproduct of phosphoric acid processes, in a slurry form in a large gypsum storage facility (provided separately on the facility site). The ERICA tool was used to evaluate the impact of radiation on nonhuman environments for mineral processing and waste storage for risk estimation. The impact of radiation on the environment due to the phosphogypsum stockyard was negligible with a screening dose of less than 10 μGy h−1. However, to conservatively evaluate the environmental impact of rain and wind in the phosphogypsum stockyard, the soil at the interface of the stockyard, where plants could not grow, was considered as an input value, and the estimated dose rate of shrubs was found to be 45 μGy h−1. The effects of the phosphogypsum stockyard on the surrounding environment accounted for 95–100% of the total dose for internal exposure in biota. In general, radium was found to be the highest contributor to biota, and the next lead and polonium were contributors to the dose. The findings contribute to an understanding of the radiological impact of waste stored and disposed of at the facility on the environment and biota (all routes of exposure) and to developing sustainable operations and pollution monitoring policies.