MELTER-ISV Simulator is being developed as the industrystandard computational model for simulating in-situ vitrification (ISV) processes that are currently being considered as alternative remediation technologies for hazardous-waste sites. The advanced state-of-the-art computational model is able to simulate the transient, three-dimensional, chemically reacting, multi-constituent-material, multi-phase [solid, liquid, gas (vapor)] convection-flow and heat-transfer conditions in the melt and in the surrounding ground, during ISV processes. Therefore, it will be able to predict, accurately, the detailed geometry of the molten ground-materials that can be generated during a site-specific ISV process and, consequently, whether or not the planned site-specific remedial action program can actually stabilize and immobilize by encapsulation, the contaminants at the hazardous-waste site. MELTER-ISV Simulator establishes the urgently needed computational analysis capability for the emerging ISV technology which can be used by the regulatory agencies; in feasibility studies; by the research and development (R&D) organizations; and the industry in the engineering-design and planning of site-specific ISV systems that can be implemented, cost-effectively, as remedial action programs for hazardous-waste sites in the United States and around the world.The potential commerciai application as described by the awardee: MELTER-ISV Simulator will be used as commercially available software (leased) by consulting services as: (1) feasibility studies; (2) design and planning projects for site-specific ISV systems; (3) R&D projects for advanced ISV processes and technology; and (4) for international marketing.