The results from the BETA molten core/concrete interaction (MCCI) experiments conducted at Kernforschungszentrum Karlsruhe (KfK) and the associated analyses using computer models developed by KfK and by Sandia National Laboratories, i.e., WECHSL and CORCON, are described. Two important observations were made in the BETA steady-state tests: The first observation could be modeled by WECHSL and CORCON by modifications when interface heat transfer considered a “transition boiling” analogy model. The second observation was not modeled but is expected to be important during the high-temperature phase of the MCCI when fission product release is of concern. These results suggest that the BETA experiments provide necessary information to validate MCCI models for silicate (basaltic) concrete. For limestone (carbonatic) concrete, there are still open questions that further tests must address.