WELDING AND CUTTING METHODS FOR BLANKET SUPPORT LEGS OF FUSION EXPERIMENTAL REACTOR

A modular blanket has been proposed for a fusion experimental reactor, such as ITER, to enhance its maintainability as well as improve its f ablicability. The blanket module is connected to a strong back plate v ia support legs protruded From both of the module and the back plate. A welding approach has been investigated for the joining of the suppor t leg that is 70 mm thick to withstand electromagnetic forces and with limited welding/cutting heads working space of 100 mm x 150 mm adjace nt to the support leg. After comparison of several methods, e.g. NGTIG , NGMIG and iodine laser, NGTIG has been selected as a reference for w elding and plasma cutting for cutting. Iodine laser has been chosen as an alternative for both of welding and cutting. Through preliminary d esign studies, the possibility of small welding/cutting heads includin g their driving systems available to the limited space has been shown. Maintenance route for in-situ module replacement with temporary fixtu re jigs has been also investigated.