Benchmarking of Structural Materials Pre-selected for Advanced Nuclear Reactors.

To enhance the future role of nuclear energy systems, several innovative reactor designs have been proposed (e.g. Generation IV, INPRO, ADS or ITER). These new systems would enhance sustainability and reduce radioactive wastes in the nuclear fuel cycle, further enhance reactor safety, improve economics for electricity production and new applications such as the supply of process heat and/or hydrogen production, and increase proliferation resistance. The operating regimes for the structural materials in these innovative new reactor concepts extend to higher temperatures and irradiation doses than in existing power reactors and the design life will be extended to at least 60 years. In addition, some new coolants provide potentially more aggressive environment. In order to achieve these objectives, durable and expensive works, as well as intensive information exchange, are needed to develop and qualify new materials for key structural components. Therefore, international efforts should be concentrated on testing new materials.  Several recently developed structural materials have very promising characteristics, especially for application in primary components of innovative nuclear reactors. Among these are reduced activation ferritic-martensitic steels and vanadium alloys, oxide dispersion strengthened (ODS) steels, and silicon-carbide composites (SiC). Special attention should be given to materials for the nuclear fuel cladding and the reactor vessel since they act as the main barriers to release of fission products. For these and other innovative materials, continued activities related to research, development and qualification are urgently needed, hence coordinated research efforts of candidate materials should be initiated. These efforts should combine studies of their long-term stability and microstructural behaviour. Today there is clear evidence of high interest from many Member States, and various research groups would like to directly contribute to planned Round-Robin exercise in order to fully characterise and test recently developed ODS class of steels for fission and fusion applications.