The Structural Design of a CFETR Divertor IT with RH Compatibility

A single divertor module is generally composed of an inner target (IT), a dome, an outer target (OT), and a cassette for a tokamak fusion reactor. As the plasma-facing components (PFCs), the IT, dome and OT are highly likely to be destroyed, while the cassette, in principle, is not damaged. The neutron irradiation dose anticipated for the China fusion engineering test reactor (CFETR) divertor is about one order of magnitude higher than that of ITER. Therefore, the neutron-rich environment in the future device needs the implementation of teleoperation for component replacement.

These days, divertors have two maintenance strategies, integral and separated, respectively. In the second version, the water-cooled divertor design of CFETR, a separate maintenance scheme was chosen in which a damaged PFC is removed from the vacuum vessel. The overall structure design of the IT, the remote handling (RH) compatibility of the IT, and the IT stainless steel support design are presented first in this paper. Then, a material choice suitable for the IT target is discussed. Finally, a hydraulic analysis of the IT cooling system and a thermal analysis of the bolts are carried out to testify to the rationality of the IT target structure design. This provides a possible technical solution for the PFC structural design in the fusion reactor divertor.