This session will delve into critical issues surrounding the very long-term safety of high-level nuclear waste (HLW). The discussion will focus on four key topics: (1) the relatively high level of hazard posed by HLW essentially indefinitely, (2) the foundations and limitations of the commonly used time horizon of up to one million years in safety assessments, (3) whether geology provides a permanent or merely temporary solution for long-term waste containment, and (4) the ethical considerations our societies must confront in addressing the environmental and human health implications of HLW indefinitely.

The session format can either consist of individual presentations addressing these topics or be structured around a keynote presentation followed by a panel discussion, with the audience having the opportunity to engage directly. In the event that no other presenters are available, I am willing to deliver the keynote presentation based on my own research, where the radiation hazard of both spent fuel and vitrified HLW is quantitatively assessed. This research, which will be published in a peer-reviewed journal by the end of this year, highlights the overlooked extended timescales in HLW management and challenges common comparisons of HLW radioactivity with that of the original uranium ore.

This session will be of particular interest to stakeholders in radioactive waste management, policymakers, researchers, and ethicists concerned with nuclear safety and sustainability.