Modeling the Transport of Activated Corrosion Products in the WCLL PbLi Loop for ITER and the EU DEMO With the GETTHEM Code.

This work presents the results of the implementation in the GEneral Tokamak THErmal-hydraulic Model of available models for the generation and transport of any dispersed material in flowing PbLi eutectic mixture. In particular, the focus is on Activated Corrosion Products circulating as solid suspension in the PbLi loop of the Water-Cooled Lithium-Lead Breeding Blanket of the EU DEMO fusion reactor. A simple test case is used to show that the distribution of the concentration of activated corrosion products at any point of the PbLi loop, both in the water-cooled lithium-lead breeding blanket and in the related ITER Test Blanket System, can be determined by the model. Moreover, thanks to the model's dynamic nature, operational transients can be simulated; for instance, starting from zero impurities in the PbLi alloy, the evolution of the concentration of corrosion products is shown, until the steady-state is reached. The results obtained with this tool can be useful not only for radiological safety purposes, but also because activated corrosion products may affect the PbLi flow itself and the efficiency of the tritium removal system, with consequences on the achievable Tritium Breeding Ratio. A rigorous verification of the model is also performed.