Plasma Stabilization Conducting Shells and their Impact on TBR and Activation in CLiFF Design

Plasma stabilization and plasma elongation are best achieved by keeping a stabilizing shell as close as possible to the plasma. In CLiFF design, a 2-cm-thick flowing liquid layer is placed in front of a solid FW and is thought to be used as an active conduction shell if its conductance is relatively high such as with liquid lithium. On the other hand, higher conductance is achieved by solid shells (e.g. Cu, Al, FS, W, V alloy). In the present study, the adverse effect of this stabilizing shell (whether it is liquid or solid material) on tritium breeding ratio (TBR) is investigated. Among the design features that quantify this effect are: the type of breeder and structure, the degree of Li-6 enrichment, the material and thickness of the shell, and whether or not there is a front beryllium multiplying zone in the blanket. Additionally, the presence of a solid conducting shell near the FW will impose a safety concern in the case of LOCA. The present study addresses this concern and comparison of the level of decay heat and waste disposal rating is made among the candidate materials for the stabilizing shell.