Mechanical arrangement for assembly of IWS blocks to ITER Vacuum Vessel

The ITER In-Wall Shielding (IWS) consists of blocks sandwiched between inner and outer shells of the ITER Vacuum Vessel. Typically an IWS block is assembled to vessel by first fixing a lower bracket to the vessel rib, followed by putting the block on the bracket and then fixing the upper bracket to block and rib using bolts and cap screws. As the ITER Vacuum Vessel consists of several ports and penetrations, the IWS block is aligned along different paths and angles before putting the block on the Vessel. A conventional system cannot handle the heavy IWS blocks with required flexibility, hence a mechanical system is proposed to assemble the IWS blocks at multiple degrees of freedom with fine accuracy. This paper describes a mechanical system proposed to assemble the blocks at the configuration with the required precision.