Design study of plasma-facing components for JT-60SA

The Japanese national project toward DEMO reactor and a satellite tokamak project for ITER in a Broader Approach with Japan and EU collaboration are combined as the JT-60SA (Super Advanced) project. Design of PFC for JT-60SA is widely modified from original national plan due to the increase of plasma heating power and annual neutron yield. Mono-block divertor target aiming at power handling of 15 MW/m2 should be adopted to an outer divertor, because expected heat flux will exceed 10 MW/m2. Since high coolant flow velocity of 10–12 m/s is required to enhance heat transfer and critical heat flux for swirl or screw tube, primary coolant water system is increased from 1300 to 4600 m3/h. Remote handling system similar with ITER blanket manipulator is adopted to maintain plasma-facing components. Divertor cassette has 10° width in toroidal direction and weight of 300 kg itself due to the limitation of port width and manipulator.