Chemical composition and properties of lava-like fuel-containing masses from the ―Shelter‖ (LFCM) are considered. It is noted the necessity of further LFCM conditioning to ensure the safety of their prolonged storage and disposal in a geological repository. As an optimal method of conditioning it is suggested the joint vitrification of LFCM and of liquid boron-containing radioactive waste from VVER NPP using an induction ―cold crucible‖ melter.

Keywords: borosilicate glass, vitrification, lava fuel-containing mass, liquid radioactive waste, high-level waste.