Assessment of Spherical Tokamak Reactors Comparing with Other Fusion Power Plants

抄録

The 1-GWe D-T normal-conducting spherical tokamak (ST) reactor is designed using PEC (Physics-Engineering-Cost) system code, and is compared with conventional superconducting tokamak reactor (TR) and other fusion reactors. Especially two reference ST designs and one reference TR design are defined, and their design and environmental parameters are compared. It is found that the cost of electricity (COE), the life-cycle CO₂ emission rate and the energy payback ratio (EPR) strongly depend on plasma aspect ratio in ST designs, in contrast to TR designs which are insensitive to plasma aspect ratio. The clarification of plasma beta and confinement improvement factor in ST plasmas is crucial for searching for optimized reactor designs.