The Water Cooled Lithium Lead (WCLL) blanket is one of the four breeder blanket technologies under consideration within the framework of the EUROfusion Consortium activities. The aim of this work is to develop a preliminary model that can track tritium concentration and tritium fluxes along each part of the WCLL blanket and its ancillary systems at any time.

Because of tritium’s nature, the phenomena of diffusion, dissociation, recombination and solubilization have been taken into account when describing the tritium behavior inside the lead-lithium channels, the structural materials and the water coolant circuits. The simulations have been performed using the object oriented modeling software EcosimPro.

Results have been obtained for the pulsed generation scenario of the European demonstration power plant (DEMO). The tritium inventory in every part of the blanket has been computed. Permeation rates have been calculated as well allowing to know how much tritium ends up in the coolant system and how much remains in the liquid metal. The amount of tritium extracted from the lead-lithium loop has been also obtained. All this information allows having a global perspective of tritium behavior all over the blanket at any time.

The model provides valuable information for the design of the WCLL blanket. More complex upgrades are planned to be implemented based on this model in future stages of the EUROfusion project.