Development, Characterization and Testing of Materials of Relevance to Nuclear Energy Sector Using Neutron Beams

Nuclear technologies such as fission and fusion reactors including associated waste storage and disposal rely on the availability of not only nuclear fuels but also advanced structural materials. 19 institutions from 18 Member States (Argentina, Australia, Brazil, China, Czech Republic, France, Germany, Hungary, Indonesia, Italy, Japan, the Netherlands, Republic of Korea, Romania, Russian Federation (two institutions), South Africa, Switzerland, USA) cooperated in this CRP with the main objective to address the use of various neutron beam techniques for characterization, testing and qualification of materials and components produced or under development for applications in the nuclear energy sector.

The CRP brought together stakeholders and end users of neutron scattering, neutron diffraction and imaging facilities to investigate materials for applications in nuclear energy sector. The CRP was an optimal framework to network different international groups dealing with the characterization and developing of nuclear materials, to establish new cooperation or refresh existing ones. The scientific presentations and discussions at the project meetings inspired new experiments and provided valuable results. A number of Round Robin exercises proved to be an effective way for testing and harmonizing the experimental methods applied and the reproducibility of the effects observed in the materials. It also has been shown through concrete examples that neutron scattering and imaging facilities could be improved thanks to the cooperation among groups with long experience and leading in their field and groups developing/modernizing their facilities.

This CRP was a successful and extremely valuable project: a broad spectrum of high level expertise was gathered, good equilibrium among developed and developing countries, providing a great opportunity for joint activities and complementary neutron beam techniques for material research and characterization. The important role and unique capability of neutron scattering in this particular field was highlighted, e.g. work with bulk materials, possibility to investigate radioactive samples, studies of samples in the presence of magnetic fields and tests of sensitivity to hydrogen at extreme conditions, and certainly should continue in the future.

In summary, the CRP scientific topics mainly focused on materials relevant for the present and future nuclear technologies, such as Oxide-dispersed-strengthened (ODS) steels, Zirconium based materials, welded structures and objects, and irradiated materials. The most important methods employed were: Neutron diffraction applied for the investigation of the phase compositions, the determination of dislocation densities and in particular for residual strain/stress measurements; Small angle neutron scattering to investigate inhomogeneities like irradiation defects or hydrogen precipitates; Neutron radiography and tomography to investigate macroscopic defects or element/isotope distributions.