RAFM steels (e.g. Eurofer) are considered as struc-tural material for blanket components of future fusion power plants. One of the envisaged blanket concepts to be tested in ITER foresees the application of a liquid breed-er, the eutectic lead alloy Pb-17Li. Various corrosion experiments have been made in the past, mostly conducted up to temperatures of ca. 480°C, with respect to deter-mine corrosion rates and mechanisms and comparison of the results with earlier tested RAFM-steels of type F82H-mod., Optifer and Manet. In the mean time the envisaged operational temperature increased to around 550°C and flow rates may also have changed. Thus extrapolations of the RAFM-steel corrosion behavior determined in the past to the higher working conditions may be problematic due to large uncertainties in reliability and, additionally, only low knowledge on transport of dissolved components in the Pb-17Li flow is present.

Therefore, the development of modeling tools for de-scribing Pb-17Li corrosion was of absolute necessity. The modular structured code MATLIM is based on physical, chemical and thermo-hydraulic parameters and, in the first stage, the development was focused on the dissolu-tion of Eurofer steel and validation with test results ob-tained at 480 and 550°C in the lead-lithium loop PICOLO of FZK.