TBM testing in ITER: Requirements for the development of predictive tools to describe corrosion-related phenomena in HCLL blankets towards DEMO

Abstract

Compatibility testing of RAFM-steels in Pb–15.7Li environment has shown that liquid metal corrosion is always present and dissolution of steel elements in hot areas of non-isothermal systems takes place whereas a transport of the corrosion products and formed precipitates has to be considered in the TBM design.It is clear that for the design of a HCLL breeding blanket system for DEMO and to ensure the safety over a fusion power plant lifetime, a good knowledge of the corrosion behavior including the dominating mechanisms is required. Simulation tools predicting the corrosion behavior of bare and coated Eurofer in Pb–15.7Li must be implemented and validated in a real fusion environment where numerous physical phenomena are additionally present, compared to the state of the art corrosion knowledge, such as neutron flux, H, T permeation, MHD effects, temperature field with steep gradients.The state of the art will be shown and discussed using some of the main fundamental corrosion data selected from own testing campaigns and published literature regarding corrosion behavior of TBMs.On this basis a test matrix for TBM testing in ITER is presented in the paper and the deficits in present knowledge are outlined deviating future development needs in corrosion.