Changes of Paradigm in Nuclear Materials Science: the CONNECT-NM Co-funded European Partnership

Nuclear energy remains the EU’s largest source of low-carbon electricity (22% in 2022). Its future depends on the industry's ability to become more competitive, by cutting costs and construction times, improving efficiency, managing waste, and ensuring safety. Achieving this requires three key paradigm shifts. First, a shift toward small modular reactors, both light-water and advanced designs, which can be built faster and more affordably than traditional large plants. Second, adopting fast reactors, which can extract over 90% of energy from nuclear fuel (compared to ~1% in current reactors) while reducing waste volume and longevity. These reactors also allow for higher operating temperatures and efficiency. Both changes of paradigm, however, impose different needs and more severe constraints on materials than in current thermal light-water reactors. Modular reactors will require advanced manufacturing processes to be successful on the market, while there is a need to improve significantly their radiation-tolerance, their compatibility with heat-carrying fluids (different from water) and their stability at high temperature in the case of fast and high temperature reactors. Achieving this within the timeframe of about one decade requires a transformation in materials science, shifting from a traditional “observe and qualify” approach to a “design and control” strategy. This means designing materials to meet specific requirements from the outset, including sustainability and long-term safety. The corresponding nuclear materials research agenda [1,2] pursues acceleration in the development and qualification of materials, through tools like material acceleration platforms, test beds for accelerated qualification paths, advanced predictive models and structured knowledge organization systems, in combination with intelligent materials health monitoring and digital twins for the safe management of the lifetime of components. Such a drive towards innovation is the goal of the recently launched co-funded European partnership on nuclear materials, CONNECT-NM [3]. References: 1. Malerba L, Al Mazouzi A, Bertolus M, Cologna M, Efsing P, Jianu A, Kinnunen P, Nilsson K-F, Rabung M, Tarantino M. Materials for Sustainable Nuclear Energy: A European Strategic Research and Innovation Agenda for All Reactor Generations. Energies. 2022; 15(5):1845. https://doi.org/10.3390/en15051845 2. Malerba L, Agostini P, Angiolini M, Bertolus M. Towards a single European strategic research and innovation agenda on materials for all reactor generations through dedicated projects. EPJ Nuclear Sci. Technol. 2022; 8:36. https://doi.org/10.3390/10.1051/epjn/2022042. 3. www.connect-nm.eu