Environmental and Economical Assessment of Various Fusion Reactors by the Calculation of CO2 Emission Amounts

Abstract

We compared the CO2 emissions of several fusion reactors. The magnetic confinement systems evaluated here are the tokamak reactor (TR), helical reactor (HR), and spherical tokamak reactor (ST). These models are calculated by the Physics-Engineering-Cost (PEC) code. The inertial confinement fusion reactor (IR) is also evaluated, assuming its driver energy and driver efficiency. In addition, different blanket modules and fuels are considered in the TR designs. To calculate life-cycle CO2 emission from fusion reactors defined by plasma parameters and radial build, we used a basic unit for CO2 weights (kt-CO2/t-material). Calculation results indicate that CO2 is emitted mainly in the construction stage of superconducting magnet systems for magnetic confinement fusion reactors. For the IR design, the driver system construction and pellet fabrication stages involve considerable CO2 emission. By comparing fusion reactors with other electric power generation systems in terms of CO2 emission, we confirmed that fusion reactors emit less CO2. Therefore, introducing a carbon tax has little effect on the economics of fusion reactors, and the cost of electricity (COE) from fusion reactors might be lower than that of oil-fired electric power plants when a carbon tax of around several hundred yen/t-CO2 is introduced.