Remote handling of the blanket segments: testing of 1/3 scale mock-ups at the Robertino facility

The remote replacement of blanket segments inside the vacuum vessel of a fusion reactor is probably the most complex task from the maintenance standpoint. Its success will rely on the definition of appropriate handling concepts and equipment, but also on a “maintenance friendly” reactor layout and blanket design. The key difficulty is the lack of rigidity of the segments which results in considerable deformations since they cannot be gripped above their centre of gravity. These deformations may be up to five times greater than the assembly clearance and one order of magnitude larger than the required positioning accuracy. Experimental activities have been undertaken to select appropriate handling devices and procedures, to assess the design of the components handled, and to review specific technical issues such as kinematics and dynamics performance, trajectory planning and control and sensors requirement for the handling devices. Work was performed in the Robertino facility where two handling concepts have been tested at a 1/3 scale.