[en] The Melt Attack and Coolability Experiments (MACE) program has been underway at Argonne National Laboratory addressing the ability of water to quench and thermally stabilize a molten core concrete interaction (MCCI) when the interaction is flooded from above. In this program, which has been sponsored by the EPRI-headed Advanced Containment Experiments (ACE) international consortium, large scale reactor material integral effects experiments have been conducted, in parallel with related modeling efforts. Plans are currently being developed for continued utilization of the MACE facility under the sponsorship of the Nuclear Energy Agency (NEA) to achieve the following objectives: (i) resolution of the ex-vessel debris coolability issue through a redirected program which focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests; and (ii) address remaining uncertainties related to long-term two-dimensional MCCI under dry cavity conditions. In terms of the ex-vessel debris coolability issue, separate effects tests are planned to provide data on key melt coolability mechanisms identified in MACE integral effects tests. The results of these tests will provide both confirmatory evidence and test data to support development of validated models for extrapolation to plant conditions. In terms of dry cavity conditions, reactor material tests are planned to address remaining uncertainties related to long-term 2-D MCCI; in particular, lateral vs. axial power split. This paper describes the essential elements of the program to address these two remaining important LWR safety issues