Mechanical Design and Fabrication of the U.S. Solid Breeder Blanket for ITER

The solid breeder blanket has been chosen as the first option for ITER, with three of the four participating international groups submitting designs utilizing solid breeding materials. This paper describes the design submitted by the U.S. group. The ITER chamber will have both inboard and outboard blankets. The outboard side is divided into 48 modules, three per TF sector, where one central module fits between TF coils and two side modules fit partially within the coils. The central module is divided into an upper and lower segment leaving space at the midplane for penetrations. These penetrations include spaces for test modules, neutral beams and RF heating units. The two side modules extend the full height of the reactor. The inboard side is divided into 32 modules with each module separated into three electrically insulated front zones. A slab configuration is used within the blanket, where Be zones are interleaved with thin LiO₂ solid breeder zones and water coolant panels. In the outboard blanket the first wall and coolant panels have toroidal channels while the inboard blanket has poloidal channels. The first wall has to be designed to be capable of withstanding the pressure generated by plasma disruptions. An independent coolant loop is used for the first wail while the blanket and shield are integrated into another loop.