Assessment status of the WECHSL-Mod3 code

The predictive capability of the WECHSL-Mod3 code is evaluated on the basis of a significant set of experiments selected from the BETA I, SURC and ACE test matrices. The prediction of concrete erosion is generally in close agreement with data for all corium compositions and concrete types. The modeling of condensed phase chemistry appears as a major contribution to the proper calculation of the tests where Zr oxidation played a role. Some discrepancies observed for the prediction of concrete ablation and melt temperature for the case of oxidic melts are discussed with respect to the modeling of liquidus/solidus temperatures, of melt-concrete heat transfer and of Zr chemistry at very high temperature. (orig.)