Manufacturing routes for stainless steel first wall panels

Hot isostatic pressing (HIP) techniques are being considered in the European Home Team as one of the fabrication routes to produce ITER-FEAT primary first wall panels (PFWP). To demonstrate the potential and the availability of such techniques, material development, innovative mock-up fabrications and numerical modeling for the production of near-net shape components are currently been studied by CEA/CEREM in collaboration with the EFDA-CSU Garching. The aim of this work is to investigate the manufacturing feasibility of advanced PFWP concepts, with reduced pitch between FW cooling channels and reduced material thickness between the FW cooling channels and the front surface, in order to improve the thermal fatigue performance of these concepts. In order to select the best fabrication route, two different manufacturing methods based on the HIP process are being considered. The first one consists in manufacturing of the first wall panel by a HIP forming technique. Mock-ups are made of a serpentine tube expanded into a proper matrix. 2-D computer modeling has been performed to estimate the serpentine deformation. The second manufacturing route is based on the powder HIP technique. Mock-ups have been made of a serpentine embedded into SS powder. In both cases, the objective was to obtain the minimum pitch between the stainless steel (SS) tubes and between the SS tubes and the front face.