ACABLoop simulation tool: Improving the activation prediction of flowing PbLi alloy in support of DEMO fusion reactor design

PbLi alloy as breeder material is considered within the EUROfusion Programme in the Water-Cooled Lithium-Lead blanket concept of DEMO fusion reactor. The PbLi travels along loops entering and leaving the Breeding Blanket for recovering the produced tritium, removing generated impurities and activated corrosion products, etc.Prediction of activation-related responses in the flowing PbLi is a key safety issue in support of DEMO design. Traditionally, the activation inventory generated in the flowing PbLi has been calculated considering a simplistic approach, valid only for a pre-conceptual analysis. Additionally, the simulation of some phenomena is not possible when using that simple methodology.ACABLoop has been conceived as a tool to overcome such limitations predicting more realistically the activation of the PbLi alloy, providing all the information related to the generated isotopic inventory in the fluid.Status of ACABLoop development is presented as well as some applications for PbLi activation in DEMO loops, proving its suitability for fusion activation calculations. Additionally, a promising first validation of ACABLoop using a water loop and a D-T fusion neutron spectrum is shown. Last improvements of ACABLoop are devoted to allowing incorporation of CFD information as a tool for increasing the reliability in some specific situations.