Impact of blanket material and configuration on the size of a tokamak fusion reactor

Abstract

On the basis of the Korean fusion roadmap, conceptual design of the DEMO and R&D on the breeding blanket are ongoing. This article addresses the impact of blanket material and configuration on the tritium breeding, shielding characteristics, and resulting size of a tokamak fusion reactor. The reactor parameters were determined via coupled tokamak systems analysis, which incorporated the effect of various materials and configurations of the blanket self-consistently with the plasma performance and the tokamak engineering constraints. In the homogeneous configuration, the minimum major radius was smaller and the TBR (tritium breeding ratio) was larger than in the vertical configuration due to an increase in slow neutron flux. In the vertical configuration, placing a neutron multiplier in front of the blanket resulted in an increase in TBR due to increased slow neutron flux. The HCSB concept among solid blanket concepts allows for a smaller reactor size which satisfies the tritium self-sufficiency and shielding requirements because of the good tritium breeding capability of the solid breeder; the HCLL concept among liquid blanket concepts does as well, due to the good shielding capability of PbLi. The outcomes of this study provide useful guidelines for the feasibility assessment and selection for the blanket concept of the tokamak fusion reactor.

Keywords

• Tritium breeding blanket
• Blanket material
• Blanket configuration
• Coupled systems analysis
• Reactor size