Conceptual design of plasma vacuum vessel for fusion DEMO considering integration of core components

A fusion DEMO will be designed as a long-term D-T reaction machine, and it will provide electricity to the grid. The core components of the fusion DEMO such as superconducting TF coils and vacuum vessel sectors become larger and heavier than those of ITER. The difficulties of manufacturing and handling increase significantly. Therefore, the conceptual design of the plasma vacuum vessel and its leg are carried out based on the consideration of assembly and disassembly processes of the core components. When the global density of the device is assumed to be same as the ITER, the total weight of the fusion DEMO would be about 77,500 tons and one TF coil weigh wound be about 1,200 tons. To carry out the easy works for assembling and disassembling, demountable superconducting TF coils are proposed which will be made of high temperature superconducting tapes so that the enough workspace can be secured. The weld joint of the vacuum vessel with a double wall structure is investigated, and the support leg is designed considering the three-dimensional displacement and the integration processes. (author)