The solidification of high-level liquid wastes (HLLW) arising from reprocessing of spent nuclear fuel represents an important step of the nuclear fuel cycle. Current technologies apply the vitrification of HLLW in borosilicate glass. A vitrification process based on the liquid-fed ceramic melter (LFCM) has been under development since the 70s at the Institute fur Nukleare Entsorgungstechnik (INE) of the Forschungszentrum Karlsruhe. Recent improvements were made in melter design regarding the processing of wastes with a high content of the platinum metals Ru, Pd and Rh. These elements are insoluble in the glass melt and form separate phases with high electrical conductivity and viscosity affecting the melter's operability. The paper describes the advanced melter technology and gives information about the operational performance of the new design.
