Speaker
Description
Fusion reactions in a hydrogen-based plasma, as foreseen with ITER, expose the materials to high temperatures and 14 MeV neutrons. A powerful electromagnetic confinement of unprecedented size is designed to control the plasma and balance disruptions. Another important aspect is that ITER is intended for cyclic operation ramping up power and plasma durations.
For engineers this means to match very challenging requirements where there is no reference handbook to look for acceptance criteria’s. The designers need to account for thermal loads, mechanical loads, neutron damage, irradiation hardening, high magnetic loads and cyclic fatigue.
The development of plasma facing components have taken decades where different material combinations were studied.
After passing conventional tests to map response to thermal and mechanical loads, the candidate materials were exposed to neutrons. The irradiation testing was performed by renting slots between uranium fuel assemblies inside conventional nuclear fission reactor. Conventional fission reactors generate much lower energy neutrons than fusion reactors but provides valuable data. After irradiation the materials were tested again to measure influence of irradiation on material properties. In some cases, post-irradiation testing revealed weakened materials that was not fit for ITER and engineers had to come up with new solutions.
The purpose of this presentation is to summarize the ITER operational conditions and how qualification was performed to reach the present design of ITER plasma facing components.
