Studies on Flibe Blanket Designs in Helical Reactor FFHR

The self-cooling molten-salt Flibe blanket of FFHR is numerically analyzed, resulting the optimum first wall to be as thin as 5mm and the heat flux up to 0.25MW/m 2 to be feasible with adopting V-4Cr-4Ti as the structural material. An alternative concept of free surface using a capillary force is shown to be feasible even in helical systems, where a spiral flow is formed and drastically enhances the heat transfer efficiency. The nuclear property of Flibe blanket is modified with increasing Be amount and adopting carbon reflector, resulting the local TBR of 1.3. As an optional technique, 50% enrichment of Li-6 gives the maximum TBR of 1.4.