MHD and heat transfer considerations for the US DCLL blanket for DEMO and ITER TBM

We summarize here the results of ongoing studies for magnetohydrodynamic (MHD) flows and heat transfer in the eutectic alloy lead–lithium (PbLi), which is used as a breeder and coolant, for three US Dual-Coolant Lead–Lithium (DCLL) blanket scenarios: ITER H-H, ITER D-T, and DEMO. The paper focuses on the important blanket feasibility issues, such as the MHD pressure drop, heat leakages from PbLi into the cooling helium flows, and the temperature distributions in the insulating flow insert and at the material interface. Both ITER scenarios look acceptable, i.e., all material restrictions can be easily met. In the DEMO scenario, the flow insert operates in harsh conditions causing high temperature drop in the insert and high interface temperature between the hot PbLi and the ferritic structure that may exceed the allowable material limits.