Development of new analytical tools for tritium transport modelling

Abstract

Tritium technologies, in particular tritium extraction from lithium-lead (LiPb, 15.7 at. % Li) and tritium concentration measurement in the eutectic alloy, are among the most challenging aspects of the R&D activities envisaged for the development of ITER and the European DEMO reactor. For instance, to efficiently design the systems devoted to the extraction of tritium, such as Gas-Liquid Contactors (GLC), Permeators Against Vacuum (PAV) or Liquid-Vacuum Contactor (LVC), theoretical models for the evaluation of the permeation flux are strictly necessary. In general, the same needs arise for the description of tritium permeators, which can find their application as Hydrogen isotopes Permeation Sensors (HPS) for the measurement hydrogen/tritium solubilized in the LiPb of either the Test Blanket Systems (TBS) or the Breeding Blanket. In this paper, new mathematical tools to describe the different permeation regimes both in the gas phase and in the presence of hydrogen isotopes monoatomically dissolved in a liquid phase, thus substantiating the theoretical background of hydrogen isotopes transport modelling throughout a membrane, is presented. For the sake of completeness, theoretical models in case of absence of a membrane (LVC) are also reported.