Numerical and experimental research to solve MHD problem in liquid blanket system

Thermofluid research issues relating to self-cooling liquid blanket system for fusion reactors are discussed to find ways to realize the system. In this paper, liquid Li and Flibe molten salt are chosen as the blanket coolants. For the Li blanket system, there exists some possibility to overcome MHD problem by using three-surface coated channel with multi-layer structure. The material properties in terms of electrical conductivity required for the innermost metal layer seems achievable together with new concept that the coated material works as the structural component of the innermost thin layer. In the case of Flibe coolant, which shows very small MHD pressure drop, electrolysis occurs to result in generation of fluorine and tritium. The numerical results show that this electrolysis can be suppressed by optimizing the channel geometry. Numerical and experimental results indicate that heat transfer enhancement using pebble beds is expected when the flow velocity is relatively small to reduce the MHD effect.