Overview of the TBM R&D activities in Japan

In Japan, development of Water Cooled Ceramic Breeder (WCCB) blanket is being performed as the primary candidate of Test Blanket Module (TBM) toward DEMO. Also development of high temperature Li–Pb blanket, Li/V blanket and Flibe blanket are being performed toward the advanced DEMO blanket. Regarding the WCCB TBM development, real scale First Wall (FW) was fabricated using Reduced Activation Ferritic Martensitic Steel (RAFMS), F82H and successfully tested by heat flux equivalent to ITER TBM condition, 0.5 MW/m2, 80 cycles with the same coolant condition as DEMO. Also, real scale Side Wall (SW) and real scale breeder pebble bed structure are successfully fabricated. Furthermore, asemmbling test of the real scale FW plate mockup and SW plate mockup was performed to clarify the welding condition to form TBM box structure. All key technologies of blanket module fabrication has been addressed and almost achieved toward TBM. Regarding the development of liquid breeder blankets, all key technologies, such as, material compatibility and mass transfer, tritium recovery performance, insulation coating development, were covered, by using elementary experiments to convection loops of Li–Pb, Li and Flibe. High temperature heat exchange test up to 900 °C has been initiated by using Li–Pb test loop.