Apparatus and methods of operation are provided for a
cold-crucible-induction melter for vitrifying waste wherein a single
induction power supply may be used to effect a selected thermal
distribution by independently energizing at least two inductors. Also, a
bottom drain assembly may be heated by an inductor and may include an
electrically resistive heater. The bottom drain assembly may be cooled to
solidify molten material passing therethrough to prevent discharge of
molten material therefrom. Configurations are provided wherein the
induction flux skin depth substantially corresponds with the central
longitudinal axis of the crucible. Further, the drain tube may be
positioned within the induction flux skin depth in relation to material
within the crucible or may be substantially aligned with a direction of
flow of molten material within the crucible. An improved head design
including four shells forming thermal radiation shields and at least two
gas-cooled plenums is also disclosed.