Determination of flow distribution in a HCLL blanket mock-up through electric potential measurements

Magnetohydrodynamic experiments in a scaled mock-up of a helium-cooled lead lithium blanket module have been performed with the aim of determining the liquid–metal flow distribution inside breeder units and between sub-channels formed by the cooling plates. It has been observed that, even for strong magnetic fields, the distribution of the flow among these sub-channels is not completely uniform, i.e. inertial entrance and exit conditions still affect the flow partitioning in the breeder units. Moreover, depending on the balance between inertia, viscous and electromagnetic forces namely on Reynolds and Hartmann numbers, regions with almost stagnant or reversed flow can be observed. Since, in closed recirculation loops the accumulated tritium could represent a safety issue, their occurrence is investigated by a detailed parametric study.