Transmutation of Radioactive Waste

Munich, 24 February 2025

Transmutation is the conversion of nuclides through nuclear reactions. If transmutation were successful on a large-scale, this process could be used to convert long-lived and highly active nuclides. This could potentially reduce the space required for a deep geological repository for high-level radioactive waste and reduce the longevity of radioactive waste overall. On Tuesday, 18 February, the experts at acatech discussed the current state of research and the current outlook with 60 online participants.

In his welcoming address, acatech President Jan Wörner covered a range of topics linked to the transmutation of nuclear waste, from cultural history and chemistry to physics to current sociopolitical issues. How can we deal with radioactive waste?

Bruno Merk, RAEng Chair in Emerging Technologies at the University of Liverpool, explained the status quo and prospects of transmutation technology: the acatech project group that addressed the topic more than ten years ago was exemplary and groundbreaking because it brought together nuclear technology, repository experts, and social scientists. This interdisciplinary work is appropriate to the topic, said Bruno Merk.

Even back then, the question of what the effects of transmutation on a repository would be, was central. Optimists predict that, following transmutation, repositories for high-level radioactive waste could be designed to be significantly smaller and possibly active for “only” a thousand years (instead of millions of years). Transmutation, according to Bruno Merk, is feasible from a scientific perspective, but the technical implementation of transmutation is – as it turns out – more difficult than expected. The next step in development would be a demonstrator based on the latest scientific and technological advances. This would provide a basis for political decisions in this area. Of course, Germany must first re-establish nuclear technology in research and development.

In his role as co-chair of the National Advisory Committee for Final Storage, acatech Executive Board member Armin Grunwald, Karlsruhe Institute of Technology (KIT), embedded the technical possibilities into the public and political debate. For decades, he recalled, the question of how to deal with radioactive waste has been a divisive issue. From 2014 to 2016, the Final Storage Commission appointed by the German Bundestag developed recommendations on the basis of which the search for a final storage facility for high-level radioactive waste is being carried out – open-ended, transparent, according to legally defined technical criteria, and with public participation. Transmutation could, in principle, alleviate the final storage problem, but it is very expensive and time-consuming – and whether it will ultimately work is yet to be determined. In any case, there will never be a machine that simply transforms radioactive waste into harmless substances. From Armin Grunwald’s perspective, transmutation is currently primarily a rhetorical tool used by politicians to resume nuclear power generation.

Winfried Petry, Technical University of Munich and member of the Bavarian Nuclear Fusion Expert Commission, sees another possible application for transmutation, in addition to shortening the lifetime and reducing the radioactivity of radioactive waste, namely its use in a “closed fuel cycle” and thus a more complete utilization of the energy content of the uranium fuel. He also advocated investment in a demonstrator for a transmutation facility in light of current energy problems and the expected long period (until approximately 2100) until a final repository is available.

Can this be considered a plea for developing transmutation in parallel with the search for a final repository? Jan Wörner believes that a final decision on this cannot be made at at the moment. However, continued involvement in nuclear technology, as recently recommended by the Bavarian Nuclear Fusion Expert Commission (in German), is certainly a prerequisite for technological openness in this area. acatech will participate, develop options — and also consider their consequences.

The discussion, moderated by Anna Frey, focused on possible legal frameworks and nuclear technology expertise for the development of transmutation facilities in Germany, the avoidance of proliferation risks in transmutation, and the situation worldwide.

 

Further information:

Nuclear Technology Expertise for the Energy Transition (in German)

Social Implications of Partitioning and Transmutation Research (in German)

Safe Disposal and Deep Storage of Highly Radioactive Material (in German)