Following the accident at the Fukushima Daiichi nuclear power station, the Japanese government launched a years-long effort to stabilize and decommission the facility. One of the greatest technical challenges of this effort, which is directed in part by the International Research Institute for Nuclear Decommissioning (IRID), is the safe removal of molten fuel debris and internal furnace structures.
To enable debris removal, Mitsubishi Heavy Industries (MHI) is building a seven-meter-long robotic arm capable of withstanding up to 2000 kg of processing reaction force. Designed and verified in Simulink®, the robot’s hydraulic control system can move the arm’s six axes to achieve a positioning accuracy at the tool tip of just 5 mm—well within the IRID requirement of 10 mm.
“Working on a project such as this without Model-Based Design often entails trial-and- error methods, leading to major refactoring work performed under cost and time pressure,” says Tadashi Murata, engineer at Mitsubishi Heavy Industries. “Using MATLAB and Simulink in the initial phases of the project helped us to identify issues early. As a result, we were able to halve the time spent on development and debugging on the actual device.”