Speaker
Yuto Noguchi
(Fusion Research and Development Directorate)
Description
The ITER blanket module has hydraulic connections to the cooling water manifold. The connections are designed to be cut and re-welded remotely in the vacuum vessel during blanket maintenance due to irradiation of in-vessel components after D-T experiment. In course of the R&D activities for in-vessel pipe welding, a study [1] demonstrated that good weld quality can be achieved by correcting misalignment of weld groove, in parallel with optimizing welding conditions such as heat input and gas pressure. Thus correcting pipe misalignment and confirming that the misalignment is corrected are critical for reliable in-vessel welding of ITER hydraulic connections.
This paper presents development of in-vessel welding tool for ITER blanket remote maintenance, which consists of pipe misalignment correction tool, pipe misalignment measurement tool and welding tool. Whole concept of tooling operation by tool manipulator attached to the ITER in-vessel transporter collaborating with a dexterous manipulator for cable handling is also presented. In particular, test results of a pipe misalignment correction tool and two different types of pipe misalignment measurement tools using laser light are shown. The misalignment measurement tools are those by (a) reflection intensity measurement of incident laser to the pipe weld groove by photodetector, and (b) image observation of weld groove by near-infrared laser, respectively. In both methods, in view of limited accessibility to the hydraulic connections in ITER blanket modules, measurement of weld groove was done from the inner side of φ42 mm inner diameter pipe with 3 mm thickness. Moreover, these tools are designed to be integrated with laser welding tool. Integrated testing of pipe misalignment correction, weld groove measurement and welding is to be carried out.
Co-authors
Nobukazu Takeda
(Fusion Research and Development Directorate, ITER Project Unit, Remote Handling Technology Group, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Ryuichi Inoue
(Fusion Research and Development Directorate, ITER Project Unit, Remote Handling Technology Group, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Satoshi Kakudate
(Fusion Research and Development Directorate, ITER Project Unit, Remote Handling Technology Group, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Takahito Maruyama
(Fusion Research and Development Directorate, ITER Project Unit, Remote Handling Technology Group, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Yuto Noguchi
(Fusion Research and Development Directorate, ITER Project Unit, Remote Handling Technology Group, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
