A modular blanket has been proposed for a fusion experimental reactor, such as ITER, to enhance its maintainability as well as improve its fablicability. The blanket module is connected to a strong back plate via support legs protruded from both of the module and the back plate. A welding approach has been investigated for the joining of the support leg that is 70 mm thick to withstand electromagnetic forces and with limited welding/cutting heads working space of 100 mm × 150 mm adjacent to the support leg.

After comparison of several methods, e.g. NGTIG, NGMIG and iodine laser, NGTIG has been selected as a reference for welding and plasma cutting for cutting. Iodine laser has been chosen as an alternative for both of welding and cutting. Through preliminary design studies, the possibility of small welding/cutting heads including their driving systems available to the limited space has been shown. Maintenance route for in-situ module replacement with temporary fixture jigs has been also investigated.