Manufacturing of ITER vacuum vessel In-Wall Shielding

ITER vacuum vessel is a double wall structure, comprising of inner and outer shells. Space between two shells is filled up with ITER vacuum vessel In-Wall Shielding blocks to, (i) provide neutron shielding to toroidal magnetic field coil and (ii) reduce toroidal magnetic field ripple. There are about 8960 IWS blocks of different sizes, shapes and materials distributed over nine vessel sectors and corresponding nine field joints. Manufacturing of IWS requires various processes like water jet cutting, precision CNC machining, assembly with tight tolerances, accurate dimension measurements, spot welding, full penetration welding, Non Destructive Testing etc. Various IWS mock ups are manufactured to establish and validate manufacturing and inspection procedures. With sufficient experience gained from manufacturing and testing of mock ups, final manufacturing of IWS has started at M/s. Avasarala Technologies Limited, India. This paper describes important features of IWS design, results of mock ups' manufacturing, optimization of manufacturing and inspection processes, assembly and progress of actual IWS manufacturing.