TRITIUM RETENTION IN PLASMA FACING COMPONENTS FOR NET ITER FUSION DEVICES

This paper presents the derivation and the results of a tritium inventory assessment carried out for prototypical NET/ITER first-wall and divertor carbon-based armors, and discusses the impact of the uncertainities associated with these estimates. Transient effects associated with fusion device pulsed operation were modelled using two tritium retention models: (i) a new model primarily suitable for tritium retention analysis in porous media, and (ii) a diffusion-type model developed for metallic materials. The influence of several key factors such as the material microstructure, the flux density, the temperature range, the burn operation scenario, and the burn duration which are expected to strongly affect tritium retention is analyzed. A parametric assessment is performed for a 50/50% D-T plasma, particle fluxes in the range of 10(16) - 10(19) particles cm-2 s-1, temperatures in the range of 300-1900-degrees-C, and burn-times in the range of 400-1000 s.