Advances in Additive Manufacturing of fusion materials

Abstract

Recent analysis result in significant impact on the design of the Helium Cooled Pebble Bed (HCPB) Breeding Blanket (BB). Especially the main demanding sub-component of the BB in terms of fabrication, the First Wall (FW) is highly affected. As a matter of fact, the relevance of the developments made for the industrial fabrication of the FW used e.g. in the EU HCPB Test Blanket Module (TBM) for ITER is limited: On one hand in terms of the overall dimensions, but also in terms of geometry and cooling channel configuration. Thus, a fabrication strategy for the FW was proposed as an option in 2018 based on Additive Manufacturing (AM) offering a solution to cover the new aspects. The dedicated fabrication routine is based on Cold Spray (CS) in alternation with machining. In terms of manufacturing of non-plasma facing complex shaped thin- or double wall BB structures (e.g. Fuel Pins proposed for the HCPB BB) the use of AM also provides benefits compared to conventional technologies. Therefore, the AM process of Selective Laser Melting (SLM) is also investigated in terms of applicability for BBs. This paper gives an overview about the advances in different AM options applied for nuclear fusion structural low activation steels. Possibilities for spin-offs to other technological fields are discussed and conclusions are drawn reflecting licensing aspects and technological limits.