The ARIES-CS team has concluded an integrated study of a compact stellarator power plant, involving physics and engineering design optimization. Key engineering considerations include the size of the power core, access for maintenance, and the minimum distance required between the plasma and the coil to provide acceptable shielding and breeding. Our preferred power core option in a three-field-period configuration is a dual-coolant (He + Pb-17Li) ferritic steel modular blanket concept coupled with a Brayton power cycle and a port-based maintenance scheme. In parallel with a physics effort to help determine the location and peak heat load to the divertor, we developed a helium-cooled W alloy/ferritic steel divertor design able to accommodate 10 MW/m2. We also developed an intercoil structure design to accommodate the electromagnetic forces within each field period while allowing for penetrations required for maintenance, plasma control, coolant lines, and supporting legs for the in-vessel components.

This paper summarizes the key engineering outcomes from the study. The engineering design of the fusion power core components (including the blanket and divertor) are described and key results from the supporting analyses presented, including stress analyses of the components and thermal-hydraulic analyses of the power core coupled to a Brayton cycle. The preferred port-based maintenance scheme is briefly described and the integration of the power core is discussed. The key stellarator-specific challenges affecting the design are highlighted, including the impact of the minimum plasma-coil distance, the maintenance, integration, and coil design requirements, and the need for alpha power accommodation.