AbstractFabrication studies have been performed for the first wall and blanket box structure in the fusion experimental reactor designed in Japan. The hot isostatic pressing technique has been proposed as one of the most promising candidate methods for fabricating the first wall. This paper describes the trial fabrication of a half-scale mock-up for part of an outboard module near the midplane, without the internal structure of a breeding region, to investigate its feasibility and to clarify technological issues associated with the proposed fabrication technologies.