Abstract: A current conducting melting vessel within which glass can be melted is provided. At least two induction heating coils are provided at selected locations proximate to the melting vessel. Power is selectively supplied to the coils to thereby selectively energize the coils so that the mutual induction of current in a non-energized heating coil adjacent to an energized heating coil is prevented via a switching element in power supply circuitry associated with the non-energized coil.

Abstract: A method for vitrification of high level waste to reduce the formation of persistent secondary phases comprising the steps of providing a high level waste for vitrification; providing a glass frit additive for mixing with said high level waste; redistributing selected constituents of said glass frit for mixing separately as raw chemicals with said high level waste; and, feeding said high level waste, said glass frit additive, and the redistributed glass frit constituents to a melter for vitrification of said high level waste so that formation of secondary phases is suppressed.