Reduced activation structural materials for fusion power plants - The European Union program

The competition of fusion power plants with the renewable energy sources in the second half of the 21st century requires structural materials operating at high temperatures, and sufficient radiation resistance to ensure high plant efficiency and availability. The reduced activation materials development in the EU counts several steps regarding the radiation damage resistance: 75 dpa for DEMO, and 150 dpa and beyond for fusion power plants. The reduced activation ferritic martensitic RAFM steel forms the reference for the development efforts. It can be manufactured in the EU on industrial scale with sufficient purity and shows good properties up to 825 K. The oxide dispersion strengthened, ODS, variety of RAFM steel should reach the 950 K operation limit. The EU has chosen SiC/SiC composites as the primary high temperature, 1300 K, target. Also the potential of tungsten alloys for higher temperatures is investigated. As the present materials test environments for radiation resistance are insufficient to provide design data for DEMO, the EU supports the efforts to build an intense neutron source. The EU is co-operating within IEA and IAEA co-ordinated, highly beneficial agreements. (author)