Radiological Environmental Impact Assessment for Landfill Disposal of NORM Waste in South Korea

This study developed and applied region-specific site parameters to assess radiological impacts of landfill disposal of naturally occurring radioactive material (NORM) waste in Region A using RESRAD-ONSITE. A parameter-priority scheme based on NUREG/CR-6697 was used to select key soil, environmental and radon parameters. National soil survey and hydrological data were used to derive representative values for Area A-1 with Sandy Loam and Area A-2 with Silt Loam, and 2019–2023 meteorological data were used to define environmental parameters. The source term assumed disposal of 10 tonnes of NORM residues with activity concentrations of 1 Bq/g for the U-238, U-235 and Th-232 series and 10 Bq/g for K-40, consistent with the regulatory framework of South Korea. Resident farmer, two resident, industrial worker, recreational user and landfill worker scenarios were evaluated for annual effective dose from external exposure, inhalation and ingestion. For all scenarios and both areas, the maximum annual effective doses were below 1 mSv/y, consistent with the IAEA dose limit for public exposure. Doses to residents were dominated by ingestion, whereas worker doses were dominated by external exposure and radon inhalation, highlighting the importance of incorporating region-specific site parameters into NORM landfill assessments.