We investigate the behavior of materials exposed to energetic particle irradiation. The work contributes to the program NUSAFE (Nuclear Waste Management, Safety and Radiation Research) of the Helmholtz Association, it is tightly integrated in international collaboration.

Neutron irradiation provokes the formation and long-term evolution of nm-scale defects such as dislocation loops and solute atom clusters. These defects give rise to hardening accompanied by a reduced fracture resistance of reactor pressure vessel steels of running nuclear power plants. Materials for advanced reactor concepts will be exposed to higher operation temperatures and higher doses of neutron irradiation.

The overall objectives of our research are to elucidate the mechanisms of irradiation-induced damage in Fe-based structural materials and to assess the resulting changes of the mechanical properties.

We work on two main directions:

• In the case of running nuclear power plants, we focus on long-term irradiation effects in reactor pressure vessel steels arising from life-time extensions beyond 40 years of operation.
• Our work in the field of advanced reactor concepts is focused on the emerging classes of ferritic/martensitic Cr-steels and oxide dispersion strengthened (ODS) steels.

The new insight substantially contributes to the scientific background for the safety assessment of nuclear reactors. The work is embedded in the Euratom projects SOTERIA, MATISSE and M4F. A close cooperation with the Fundamentals and Simulation Group provides additional insight to the processes at the nm scale via atomistic simulation.

Our expertise:

• Mechanical testing of irradiated materials
• Characterization at the nm length scale
• Use of ion irradiation to emulate neutron irradiation effects