Abstract: A system for vitrifying all kinds of waste, including toxic, industrial, household and radioactive wastes such as those generated by nuclear power plants, including dry active wastes, ion exchange resins and aqueous wastes wherein the wastes are conditioned, blended, mixed with glass formers and then fed into a heating chamber where organic constituents of the waste are burned and inorganic constituents are melted with the glass formers to form a waste glass. The aqueous waste may be conditioned by concentrating its solids content up to as much as 90% solids. The dry active waste is conditioned, and mixed to some extent by shredders. The conditioned waste may be blended to achieve a uniform heat energy content of the waste being fed into the heating chamber. The heating chamber has a larger combustion zone to handle the greater amount of organic waste than would be expected in conventional melters, and a melting zone having a replaceable crucible and liner.