R&D achievements for vacuum vessel towards CFETR construction

Abstract

The next generation of magnetic confinement fusion experimental facility, the China Fusion Engineering Test Reactor (CFETR), is currently undergoing physical and engineering design. The essential technology research and development projects related to CFETR manufacture are in progress. As one of the demo projects for CFETR R&D, a 1/8 full-scaled vacuum vessel (VV), which aims to solve the key technologies of forming, welding, measurement, assembly, etc in the future manufacturing process of VV, was initiated in 2015 by Institute of Plasma Physics Chinese Academy of Science (ASIPP). The fabrication of two full-scaled 22.5° toroidal sectors, which are composed of two 11.25° sectors, was successfully completed in June 2019. In the manufacturing process of the VV mockup, the progress has been made in the following six aspects: engineering design and safety evaluation of the VV mockup, the high-precision forming of the hyperbolic shell, the welding deformation control of 50 mm thick full penetration structure, the nondestructive testing of the complex welds by full volume covering, the establishment of high-precision 3D measurement fiducial network and the high-precision assembly of the VV parts. This article describes the progress and achievements of the above six aspects for the CFETR VV.

Evaluation of the functional acceptability of the ITER vacuum vessel

“…Figure 6 shows the three-dimensional measurement scheme and strategy for the final dimensional inspection. A portable coordinate measuring system with a laser tracker (AT 960, Leica Absolute Tracker), a retro-reflector, and portable metrology software (SpatialAnalyzer, HEXAGON, and PolyWorks, InnovMetric, respectively) are employed for the measurement [19,[32][33][34]. Because multiple measurements are undertaken, the application of a fiducial post (mounting of the target nest and retro-reflector) is required as a physical reference (figure 6(a)).…”

Numerical Analysis of Electron Beam Welding Deformation for the Vacuum Vessel Lower Port Stub of 316L Stainless Steel

“…As the safety important class (SIC) components, all welds of the VV must be fully penetrated [3]. However, the VV has extremely high manufacturing tolerance requirements, and the port stub as its sub-component has stricter tolerance requirements [4]. The port stub has complex three-dimensional features, and there are many fully penetrated joints.…”