Tritium diffusion challenges on future nuclear fusion reactors

Diffusion and retention processes of hydrogen isotopes and helium are a key issue in order to construct a successful nuclear fusion reactor for both magnetic confinement fusion (MCF) and inertial confinement fusion (ICF). The tritium self-sufficiency of the fusion reactor depends on an efficient tritium extraction protocol. Transport phenomena of hydrogen isotopes through the vacuum vessel, Breeding Blanket, and Tritium Plant components are complex and involve many physical properties. Retention of light species and evolution of defects in the first wall and structural components is a major threat to their performance and operational lifetime. Diffusion parameters need to be understood and accurately assessed to design an economic and safety fuel cycle. This report is an overview on what researchers are facing up while working on hydrogen isotopes and helium diffusion aspects. A summary of transport challenges in the different components of the fusion reactors will be outlined. Also, experimental and computational simulation needs encountered during the elaboration of this work will also be described.