A systematic approach in the development of generic biosphere conceptual models for groundwater release into the Korean biosphere system from a spent nuclear fuel deep geological repository

As part of the safety case development for generic disposal sites in Korea, it is necessary to develop a generic biosphere assessment using various types of Geosphere-Biosphere Interfaces (GBIs) and Potentially Exposed Groups (PEGs) reflecting Korean natural environmental characteristics and people's lifestyles. To develop the Korean generic biosphere conceptual models for the groundwater release scenarios, a unique modeling strategy was developed, which is in line with the updated BIOMASS guidance. This strategy uses a two-staged approach; (1) selecting/prioritizing biosphere condition compositions (BCCs) that combine various types of climate, topography, GBIs, and PEGs, and (2) identifying/grouping biosphere conceptual model components (BMCs) to determine modularized BCCs (MBCCs). The outstanding features of this new systematic approach in developing biosphere conceptual models are (1) the flexibility in the selection of features/events/processes (FEPs), and (2) the modularization to facilitate addition and removal of significant FEPs influenced by the long-term evolution in the disposal site.