A Comparative Review of Hydrogeochemical Monitoring Systems for Deep Geological Disposal: Insights for South Korea

Deep geological disposal of high-level radioactive waste requires ensuring long-term safety for humans and the environment over hundreds of thousands of years. Consequently, establishing a comprehensive hydrogeochemical monitoring framework is essential to quantitatively understand the disposal environment and track its long-term evolution. This study reviews the monitoring practices of leading disposal countries, focusing on three key aspects namely disposal stages, spatial scales, and hydrologic systems, and compares them with national monitoring systems in South Korea. Applying a consistent set of hydrogeochemical parameters across these aspects is essential for building reliable datasets that support safety assessments and radionuclide transport modeling. However, South Korea’s current monitoring systems operate separately for surface water and groundwater, with differing objectives and parameters, limiting their applicability for integrated analysis. To address this issue, a comprehensive monitoring plan based on existing networks must be developed. In addition, ensuring data reliability through a systematic quality assurance and quality control framework-covering monitoring design, sampling, laboratory analysis, and data management-is crucial for maintaining the scientific credibility of the monitoring results. This study provides principal insights and directions for the establishment of a hydrogeochemical monitoring system for future deep geological disposal in South Korea.