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

Compatibility study of plasma grown alumina coating with Pb–17Li under static conditions

“…dissolution of reduced activation ferritic martensitic steel (RAFMS) with liquid Pb-17Li in the range of 32-480°C. Krauss et al [3] reported an estimated dissolution of $4 kg/m 2 of TBM steel (RAFMS) per year in flowing Pb-17Li. Such dissolution not only reduces the section thickness of structural material, but also poses a threat of choking of the test blanket module (TBM) flow channels due to precipitation of dissolved elements at colder sections.…”

MHD R&D Activities for Liquid Metal Blankets

“…Although the PbLi loop piping will be internally coated by alumina ceramics to face the high corrosiveness of PbLi and to reduce tritium permeation to the coolant and environment [109], theoretical predictions are needed to assess the feasibility and safe operation of breeding blankets for DEMO and ITER. Modelling tools have to be validated against experimental data [140]. Several experimental campaigns have been performed to study the corrosion of RAFM steels in flowing PbLi.…”

“…Since corrosion in fusion blankets is a complex phenomenon that includes kinetics of solution and deposition mass transfer and interaction with impurities, the development and validation of modelling tools is necessary for predictive design input data. To date, the code MATLIM found validation against corrosion data of RAFM steels in turbulent/mixed regime [140,146], but validation still needs to be performed in laminar conditions, as expected in BUs of WCLL blankets, where the PbLi velocity is few mm/s. Hence, experimental campaign in relevant conditions of flow and thermal gradients should be performed for code validation, also considering the effect of magnetic field and applied stress.…”

“…For reliable application of predictive tools, values for solubility and diffusivity of dissolved species have to be known with better accuracy. These properties are very important for the implementation of models as they reflect the mass transfer coefficients [140,145]. Solubility values of Fe in PbLi were obtained experimentally by various authors, but they differ by orders of magnitude [147].…”

“…The solubility value of Cr is completely missing. In addition, in most of the experimental campaigns no monitoring of impurity levels, e.g., of dissolved metals and non-metal impurities, has been performed [140]. The presence of dissolved corrosion products and the formation of precipitates affect the evaluation of corrosion rates during the tests.…”