3D geological modelling to support an environmental safety case in the nuclear sector

The Low Level Waste Repository in west Cumbria requires, as part of their environmental safety case, a geological model to support hydrogeological understanding and future development of the site. A range of legacy data accrued over the last 60 years exists which is characterized by variable data collection methods, formats, and quality. The geological model development process is atypical due to this large body of existing data and the requirements of the environmental safety case (ESC), resulting in an initial, primarily observational digital geological model. Outlined here is the approach undertaken for geological model development and includes terminology and data management practices, and considers the role of conceptualization and its direct application to the observational 3D digital model when there is significant existing observational data. Sites with significant legacy data and atypical requirements may be more common in the future, as more site investigations are completed and data are shared. The process applied is a development of Peter Fookes’ work, highlighting the importance of the conceptual model, but that application of conceptual ideas to the development of 3D digital geological models may look different in a world of increasing observational data.