Mitigating disruptions with MHD in a multiphase vacuum vessel technology *

A novel multiphase vacuum vessel technology is introduced which combines a liquid lead MHD force disperser with recent advances in silicon carbide (SiC) manufacturing to mitigate disruptions and provide a number of other reactor benefits over conventional RAFM steel vacuum vessels. The multi-layered silicon carbide vacuum vessel structure comprises a thin plasma facing layer, molten salt cooling channels, thick silicon carbide walls, and helical liquid lead channels. The SiC plasma facing layer provides a thin, low-Z material to facilitate heat transfer to the molten salt cooling channels while minimally impacting plasma performance. The helical liquid lead channels force the disruption induced currents to travel largely parallel to the magnetic field in the liquid lead rather than in the SiC structure since lead is much more conductive than SiC. This both reduces the magnitude of the forces and converts any shear stress in the lead into fluid motion and pressure gradients leading to purely compressive or tensile stresses in the thick SiC walls. Other benefits to reactor operations including the possibility of increased operating temperatures and thermal performance as well as drastically reduced radioactive waste are discussed. The modeling efforts to support the design and optimization of this vacuum vessel technology are presented as well.