Naotaka Suganuma

Decreasing Waste of Laser Cutting by Metal Fume Capturing With Water

Decommissioning of aged nuclear reactors is planned, and cutting technologies for thick structure are necessary to reduce storage space of radioactive wastes. Though thermal cutting technology is suitable for cutting thick materials, radioactive fume is one of the problems due to increase the environmental dose. A water jet-guided laser cutting technology is one of the solutions for cutting irradiated materials, because radioactive fume is confined in the water and doze level won’t be increased. However, this technology was developed for precision machining like dicing and slotting of silicon wafers, cutting thick materials by using this process is very diffcult. In this study, cutting technology for thick material with a water jet-guided laser was discussed. Phenomenon during cutting thick stainless steel was observed by using high speed camera and optimum conditions for both water jet and laser cutting were derived. Finally, 50mm thick stainless steel plate was successfully cut by using this technology.© 2014 ASME

A Remote Operated Quadruped Robot System for Investigation of Reactor Building

A remote operated quadruped robot has been developed for disaster site which can move on stairs, slopes, and uneven floor under the radiation-polluted environment, such as TEPCO Fukushima Daiichi nuclear power plants [1][2].In particular, the control method for stable walking and the remote operation system have been developed to move on stairs in the reactor building.We applied this robot to investigation of suspicious water leakage points in reactor building at Fukushima Daiichi nuclear power plants unit2[3]. In this investigation, a small vehicle equipped with camera and a manipulator which is connected the vehicle with cable were mounted on the robot and were carried to near the target by the quadruped robot and the investigation was carried out with the small vehicle.© 2014 ASME