R. Raffray

Lifetime analysis of the ITER first wall under steady-state and off-normal loads

The lifetime of the beryllium armor of the ITER first wall is evaluated for normal and off-normal operation. For the individual events considered, the lifetime spans between 930 and 35×106 discharges. The discrepancy between low and high estimates is caused by uncertainties about the behavior of the melt layer during off-normal events, variable plasma operation parameters and variability of the sputtering yields. These large uncertainties in beryllium armor loss estimates are a good example of the experimental nature of the ITER project and will not be truly resolved until ITER begins burning plasma operation.

Progress on performance assessment of ITER enhanced heat flux first wall technology after neutron irradiation

ITER first wall (FW) panels are irradiated by energetic neutrons during the nuclear phase. Thus, an irradiation and high heat flux testing programme is undertaken by the ITER organization in order to evaluate the effects of neutron irradiation on the performance of enhanced heat flux (EHF) FW components. The test campaign includes neutron irradiation (up to 0.6–0.8 dpa at 200 °C–250 °C) of mock-ups that are representative of the final EHF FW panel design, followed by thermal fatigue tests (up to 4.7 MW m−2). Mock-ups were manufactured by the same manufacturing process as proposed for the series production. After a pre-irradiation thermal screening, eight mock-ups will be selected for the irradiation campaigns. This paper reports the preparatory work of HHF tests and neutron irradiation, assessment results as well as a brief description of mock-up manufacturing and inspection routes.

Assembly and remote handling of ITER plasma facing components

The assembly and remote maintenance of the plasma-facing components of ITER presents major challenges for the construction, operation and maintenance of ITER. The main plasma-facing components, the divertor and the blankets, are large components, with exceptionally demanding alignment requirements, and require complex support systems to sustain loads under normal and off-normal operational conditions. The plasma-facing components are designed to be maintained using special remote handling (RH) tools. These tools and the associated RH systems and processes are currently undergoing detailed design and certain key processes have been subject to extensive R&D / prototyping activities.