Accuracy evaluation and experimental plan of the Multi-Nozzle Vacuum Sieve Tray facility at the Tritium Laboratory Karlsruhe

Abstract Tritium will be produced in breeding blankets by neutron bombardment of lithium to ensure the self-sufficiency of fusion power plants. Then, this tritium must be extracted to fuel the plasma. The Vacuum Sieve Tray (VST) technique has been proposed for the tritium extraction system of liquid blankets in the European DEMO. This technique consists in extracting the tritium dissolved in Pb-16Li by generating droplets, which oscillate while falling in vacuum. The Multi-Nozzle VST (MNVST) setup was assembled at the Tritium Laboratory Karlsruhe (TLK) to study the scalability of the VST technique, as well as to serve as a preliminary deuterium/lead-lithium facility before the construction of a new rig to be operated with tritium. Numerical simulations were discussed with regard to the expected accuracy of measurements to develop an experimental plan. The amount of deuterium extracted depending on the operation conditions was estimated and its distinguishability from one experiment to another was investigated, resulting in the approval of the methodology. As a result, six equilibrium pressures (10, 50, 100, 200, 300, 400 mbar), three Pb-16Li temperatures (350, 400, 450 °C) and two nozzle geometries (1 and 19 nozzles) were selected to be tested during the MNVST experiments.