DECOMMISSIONING OF NUCLEAR INSTALLATIONS REQUIRES SPECIAL TECHNIQUES FOR THE DISMANTLING OF COMPONENTS. CUTTING OF THE HIGHER-LEVEL RADIOACTIVE COMPONENTS IS PREFERABLY PERFORMED UNDER WATER. TO ASSURE ADEQUATE CUTTING QUALITY, SOME ESSENTIAL PROBLEMS REMAIN TO BE SOLVED, SUCH AS ADAPTIVE PARAMETER CONTROL, EXACT POSITIONING OF THE CUTTING TOOL AND CONTROL OF CUTTING ACTIONS UNDER WATER. SUITABLE CONTROL SYSTEMS AND SPECIAL SENSORS HAVE TO BE MADE AVAILABLE.
THE PRINCIPAL AIM OF THIS RESEARCH IS TO CONTRIBUTE TO HIGH-QUALITY CUTTING UNDER WATER BY THE DEVELOPMENT AND APPLICATION OF INNOVATIVE CONTROL SYSTEMS AND SENSORS APPROPRIATE FOR A WIDE RANGE OF DISMANTLING TASKS IN NUCLEAR INSTALLATIONS.
THE DEVELOPED SYSTEM WILL BE TESTED BY APPLICATION TO VARIOUS UNDERWATER CUTTING PROCEDURES IN COLLABORATION WITH UNIVERSITAT HANNOVER (CONTRACT NR FI1D-0036).
Research and development focused on the development of different sensor systems and their application to cutting tasks. A new image processing system was developed, along with a modified underwater television camera, for optical process control (in plasma and abrasive wheel cutting). To control process parameters different inductive, ultrasonic and optical sensors have been modified and tested.
A workpiece recognition system was developed which enables the workpiece position under water to be measured in 3 dimensions by means of a camera system. In addition, there is the potential to adapt handling movements in accordance with camera information. Fine positioning is performed with the help of additional inductive and optical sensors. The overall performance of the system was tested and demonstrated with a 4-axis manipulation system. We were able to conclude that the decommissioning of nuclear components by an automated under water system is definitely possible, provided that the water is clean and that components stand clearly out against the background.
B.1. DESIGN AND ASSEMBLY OF AN APPROPRIATE SYSTEM FOR UNDERWATER WORK PIECE RECOGNITION, INCLUDING OPTICAL SENSING, IMAGE PROCESSING AND ANALYSIS, FOLLOWED BY PRACTICAL TESTING WITH VARIOUS CUTTING TECHNIQUES.
B.2. SPECIFICATION, HARDWARE AND SOFTWARE DEVELOPMENT FOR REMOTE CONTROL OF THE CUTTING TOOL, PROVIDING FOR AUTOMATIC POSITIONING AND COLLISION AVOIDANCE.
B.3. DEVELOPMENT OF A SYSTEM FOR THE CONTROL OF THE CUTTING ACTION, INCLUDING HARDWARE AND SOFTWARE, AND SUBSEQUENT TESTING OF A PROTOTYPE.
B.4. DEVELOPMENT AND TESTING OF AN ADAPTIVE CONTROL SYSTEM, ASSURING OPTIMUM CUTTING CONDITIONS FOR VARYING CUTTING PARAMETERS (NATURE AND THICKNESS OF MATERIAL, CUTTING SPEED AND LENGTH).
B.5. CONCLUSIVE ASSESSMENT OF OBTAINED RESULTS AND IDENTIFICATION OF REMAINING TASKS.