Batch type melting and mass-forming device, and dissolving and mass-forming method

A melting crucible and a mass-forming crucible are disposed vertically and contained in an atmospheric chamber. Oxides as radioactively contaminated materials and a required amount of reducing agent are supplied to the melting crucible. High frequency electric currents is supplied to an upper and lower induction coils in the melting crucible. The temperature of a portion of the materials is risen by induction heat, and then oxides start melting. When the temperature of the oxides rises, and self heat generation is started, the supply of the high frequency electric current for the lower induction coil is stopped. Electric power is supplied to the lower induction coil when the melting reduction reaction reaches saturation. When an opening of a predetermined size is formed on the reactor bottom, a high temperature finger inside a molten material-discharge nozzle is transferred. Then, the molten metal and molten oxides are charged into the mass-forming crucible. The molten materials charged into the mass-forming crucible are gradually cooled and formed into solids. (I.N.)