Pre-study of a detritiation process for plasma facing components in the ITER hot cells

Abstract

In ITER and future fusion reactors, high heat flux (plasma facing) components will be replaced at regular intervals. Before being stored in hot cells or sent to final disposal, these components or parts of them must be detritiated to recover the large quantities of tritium still contained in the matrix (recycling tritium as fuel) and facilitate the waste acceptance in storage. This paper aims at evaluating the capability of a detritiation process to match the ITER requirements.For that purpose potential detritiation methods have been analysed in terms of detritiation performance leading to the choice of a reference process based on thermal treatment. In parallel, some detailed data concerning the waste have been compiled mainly concerning the amount of waste to treat, and its tritium specific activity with its profile in bulky materials. Since no tritium profile is currently available in ITER documents, an estimation of such profile has been performed based on the modelling of tritium diffusion into the plasma facing components. Thus, the reference detritiation process has been evaluated by a simple but representative modelling. Basically, this first approach enables to confirm the interest of such thermal process. Nevertheless, its design in the ITER hot cells requires a more sophisticated approach.