Test blanket modules in ITER: An overview on proposed designs and required DEMO-relevant materials

Within the framework of the ITER Test Blanket Working Group, the ITER Parties have made several proposals for test blanket modules to be tested in ITER from the first day of H–H operation. This paper gives an overview of the proposed TBMs designs, of the ITER boundary conditions and of the expected TBM operating conditions. Operating conditions will vary throughout the various ITER phases, starting from the initial H–H phase where no neutrons and, therefore, no nuclear volume heating will be present, to the later D–T phase where pulses of up to 3000 s length may be expected. The paper is focused on the design requirements for the materials and subcomponents that will be used in the various TBMs, from the viewpoint of both the materials performance and the required R&D.