Study on the soil evaluation methodology of on and offsite Kori Unit 1

Abstract

To optimize site remediation and reuse, we evaluated contamination of the soil surface and sub-surface in situ, inside and outside of Kori Unit 1. Realistic dose modeling was performed using RESRAD-OFFSITE code, accounting for air dispersion, groundwater transport, and the positional movement of secondary contamination. The Derived Concentration Guideline Level (DCGL) was derived; this is a useful guideline value and exposure factor for estimating maximum groundwater concentration. Site-specific parameters were used to analyze the maximum contributed exposure pathways in and out of the site, and preliminary dose assessment was performed for offsite ‘Area 1’. This study provides a general guideline for soil evaluation of nuclear power plants decommissioning site, from surface and subsurface soil contamination to the establishment of a basement fill model. It may be used as basic site evaluation methodology and guideline values based on this characterization of Kori Unit 1.