Design And Analysis Of Remote Handling Compatible Structures For CFETR Divertor Module

As one of the most important in-vessel components in vacuum vessel, the divertor module plays an essential role in fusion reactor. It can exhaust particles, He ashes and heat loads generated by fusion reaction. But it can be easily damaged due to the high temperature and high radiation environment which needs to be maintained regularly. However, the maintenance for the divertor will have to be handled in remote ways by manipulating the computers and robots rather than by personnel directly because of neutron activation to exchange the in-vessel components, namely,remote handling(RH).The remote handling system for the divertor module includes the divertor module itself, transferring tools, welding tools, cutting tools and end-effectors, et al.As the compatible structures, support structures and cooling pipes, they are important for the remote handling process. In this paper, the inner and outer supports compatible with remote handling ways for CFETR divertor module and the process of the welding and cutting for the cooling pipes are discussed based on the analysis of spatial degree of freedom theory and stability theory of a rigid body. Then four schemes about RH compatible supports are put forward. And according to the distribution of RH ports, there are three divertor modules for every port to handle: one central divertor module located in front of the port and two second divertor modules located in the left and right side of the central divertor module. At the same time, due to the instability of the plasma, Halo current and Eddy current would be generated when the plasma disrupts which will leads to the electromagnetic (EM) loads occurring. Therefore, the newly designed support structures should meet these requirements: high efficiency, reliability and high strength to resist EM loads. It can still fix the divertor module well even though the EM loads existing. The electromagnetic analysis is based on the disruption time 16ms, four working situations are put forward: the first situation is Halo current is only; the second situation is Eddy current is only; the third situation is the Halo current generated the maximum elctromagneic force coupling with Eddy current; the fourth situation is the Eddy current generated the maximum electromagnetic force coupling with Halo current.According to the analysis results, the supports, especially the inner support, are optimized to meet the working requirements.Then the installation processes of the divertor module in the virtual environment are conducted according to the different design schemes leading to the different simulation process and different ports to choose simulation methods in the different port. During simulation, the newly design supports are validated to ensure that they are feasible to work in the virtual environment.In addition, as the other aspect of the compatible structures, the cooling pipes in diverter should be considered about how to connect the pipes in the vacuum vessel outside when the divertor module is fixed in the vacuum vessel. On the other hand,how to disconnect the pipes when the divertor module needs to be maintained,disassembled and replaced which are discussed in this paper accordingly. Firstly, the connection between pipes is operated by welding, and then the seal ring is added in the area of welding seam for the air tightness. When disassembling the divertor, the seal ring should be taken away, and then the pipes are cut by cutting tools.