| Popis: |
According to the 2nd master plan for high-level radioactive waste(HLW) announced by the South Korean government in 2021, the operation of the HLW disposal repository from site selection is planned to be carried out within 37 years. In particular, the site selection was decided within 13 years after the start of the project through a step-by-step process like other countries. Unlike Northern Europe such as Sweden and Finland, where crystalline rocks are the main composition, South Korea has various rock types similar to Switzerland. The Korea Institute of Geoscience and Mineral Resources published 8 types of geoenvironmental information maps, including rock types, lineament, faults, and geothermals etc., which can be used in the national screening stage. Geoscientific researches are being conducted for each rock type in consideration of the distribution area of rock types in the South Korea obtained from the geoenvironmental information map. Considering the depth of HLW disposal repository, drillings are performed at a depth of 750 m according to the rock types, and evaluation parameters for each research field used in basic and detailed investigations are obtained. Investigations using deep boreholes, which began in 2020, were conducted in granite, sedimentary rocks including mudstone and sandstone, and gneiss. Another investigation is planned for volcanic rocks next year. The evaluation parameters obtained during the geoscientific investigation include geological parameters such as lithology, joint and fault, hydraulic parameters such as hydraulic conductivity and storage coefficient, geochemical parameters such as hydrochemistry, sorption and nuclides, and geothermal parameters such as thermal conductivity and geothermal gradient. There are also mechanical parameters such as strength, and in-situ stress. These data are expected to be used as basic data for site selection for HLW disposal in Korea in the future. |
