Radioactive waste gets generated at different stages of nuclear fuel cycle like mining/milling, fuel fabrication, reactor operation, reprocessing of spent fuel and the production & application of radioisotopes for various industrial, medical and research purposes. High Level radioactive Waste (HLW) is generated during reprocessing of spent nuclear fuel and it contains most of the radioactivity present in entire fuel cycle. Vitrification of HLW in borosilicate matrix is being practiced using induction heated metallic melters at industrial scale plants at Tarapur and Trombay [1]. The nature of HLW largely depends on off – reactor cooling of spent nuclear fuel, its type and burn – up, and reprocessing flow sheet. In view of varying characteristics, processing of HLW at Tarapur and Trombay has offered a wide spectrum of challenges in terms of development of matrices and characterization to accommodate compositional changes in waste. The present paper summarizes details of extensive R and D efforts made in the Department of Atomic Energy towards development and characterization of glass formulations for immobilization of HLW.