The Decay Days: History, Purpose, Challenges, and Future Perspectives

The Decay Days (Deep gEologiCAl repositorY Days) represent a unique network initiated to foster open scientific exchange among early-career researchers working in the field of nuclear waste disposal. The idea originated from the need for a platform that enables honest discussions about scientific challenges, methodological approaches, and the individual experiences of young professionals – beyond the formalities and institutional frameworks of conventional conferences.

The first Decay Days took place in Potsdam from 02.-04. September in 2020. Due to the Covid-19 pandemic, the event had to be adapted to a hybrid format, combining digital and in-person participation. The second edition was held in Mont Terri, Switzerland, from September 21 to 23, 2022. The third and most recent Decay Days was hosted in Braunschweig from the 26.-29. September 2023, once again bringing together young scientists from various institutions. For the 3. Edition of the Decay Days the organizers changed, maintaining the continuity and spirit of the initiative after the previous organizers were unable to take over the planning once again after they planned the Decay Days in 2020 and 2022. At each event, keynote speakers from multiple international institutions delivered presentations on their research, whilst also participants had time to present their own work. After Mont Terri and Braunschweig, no editions were planned for 2024 or 2025 due to limited organizational resources and funding constraints.

The success of the Decay Days lies in its informal yet scientific focus. It offers early-career scientists and PhD researchers a rare opportunity for open dialogue – scientifically and personally – on what works well in their research and where challenges remain. The event deliberately avoids formal hierarchies, extensive moderation, or elaborate catering in order to maintain a relaxed atmosphere conducive to genuine exchange.

However, organizing the Decay Days comes with substantial challenges. There is no permanent financial structure behind the initiative, and the aspiration to remain independent of institutional sponsors (such as regulatory bodies or waste management organizations) often conflicts with the financial reality. Invited keynote speakers require honoraria, venues cost money, and the time invested by organizers – who typically plan the event alongside full-time research obligations – must also be considered as a form of personal contribution.

Looking ahead, the sustainability of the Decay Days depends on establishing a more resilient organizational framework. Proposals are being developed to secure targeted funding and there is the idea to form a permanent coordinating committee consisting of junior scientists from different institutions engaged in radioactive waste disposal. This would enable a better distribution of responsibilities, define clear roles, and reduce the organizational burden on individuals – ultimately allowing the Decay Days to grow while preserving its core values of openness, independence, and peer-driven scientific exchange.