DEVELOPMENT OF A PIPE CUTTING TOOL FOR ITER BLANKET REMOTE HANDLING SYSTEM

抄録

This paper reports on the development of a Pipe Cutting Tool for the Blanket Remote Handling System, an essential tool for remote maintenance of the Blanket Module (BM) attached to the Vacuum Vessel (VV) of the international fusion experimental device, ITER. The BM, comprising a First Wall (FW) and a Shield Block (SB), necessitates cutting and welding water cooling pipes before removing or after installing the BM. Ensuring quality welding without leaking and with strength is crucial to maintain the vacuum environment inside the VV. Therefore, before blanket replacements, a deformation of the pipe is required to be as small as possible after cutting.

In this study, we have designed the Pipe Cutting Tool with a pad-type centering mechanism and fabricated prototype pipe cutting test equipment to evaluate the effectiveness of the developed mechanisms. This design enables the Pipe Cutting Tool to mitigate its own weight during cutting in any orientations and maintain load stability. We conducted the cutting tests under multiple cutting conditions. Specifically, we identified the influence of cutter feed rate to the pipe deformation. Consequently, we have confirmed the cutting condition to minimize the deformation of the pipe in the event that the feed rate is below 0.004 mm/s using the equipment. In the past, the pipes processed with machining were used for the welding tests, simulating the pipe weld after FW replacements. However, in the future, the welding tests will be performed using pipes cut with the swage cutter to better simulate the actual conditions.