Thermal hydraulic and structural analysis of the IFMIF-DONES liquid-lithium target system

In the IFMIF-DONES neutron source a single accelerator line delivers 125 mA of deuterons at 40 MeV to a flowing liquid lithium target with a free surface facing the deuteron beam. Neutrons with fusion -relevant spectrum are generated by a stripping reaction and used for material samples irradiation. This report presents a numerical thermal -hydraulic and structural analysis using updated design of the target system and neutronics analysis results. Simulation scope includes the target assembly, vacuum chamber with beam ducts, outlet channel, quench tank vessel and connecting elements. Simulations have been conducted with the commercial CFD code Simcenter Star-CCM + . The computational domains consist total of 47.4x10 6 fluid and 14x10 6 structure cells. The following aspects have been analyzed: center dot Temperature distribution in lithium and target system structure during beam-on operation; center dot Transient mixing of lithium in the quench tank with temperature change during the beam switchon phase. center dot Thermal displacements and stresses in the TA and QT structures. Simulations using the new distribution of nuclear heating show no significant changes in the temperature field in liquid lithium. Calculated unwanted temperature hotspots in the target structure demonstrate the need for optimization of the target design.