Geological disposal of nuclear waste: II. From laboratory data to the safety analysis – Addressing societal concerns

•Models for repository safety can only partly be validated.•Long term risks need to be translated in the context of societal temporalities.•Social sciences need to be more strongly involved into safety assessment.

After more than 30 years of international research and development, there is a broad technical consensus that geologic disposal of highly-radioactive waste will provide for the safety of humankind and the environment, now, and far into the future. Safety analyses have demonstrated that the risk, as measured by exposure to radiation, will be of little consequence. Still, there is not yet an operating geologic repository for highly-radioactive waste, and there remains substantial public concern about the long-term safety of geologic disposal. In these two linked papers, we argue for a stronger connection between the scientific data (paper I, Grambow et al., 2014) and the safety analysis, particularly in the context of societal expectations (paper II). In this paper (II), we assess the meaning of the technical results and derived models (paper I) for the determination of the long-term safety of a repository. We consider issues of model validity and their credibility in the context of a much broader historical, epistemological and societal context. Safety analysis is treated in its social and temporal dimensions. This perspective provides new insights into the societal dimension of scenarios and risk analysis. Surprisingly, there is certainly no direct link between increased scientific understanding and a public position for or against different strategies of nuclear waste disposal. This is not due to the public being poorly informed, but rather due to cultural cognition of expertise and historical and cultural perception of hazards to regions selected to host a geologic repository. The societal and cultural dimension does not diminish the role of science, as scientific results become even more important in distinguishing between the conflicting views of the risk of geologic disposal of nuclear waste.