[en] Cement is a very good matrix for immobilization for different types of wastes. In India, the cementation process has been adopted and used for the last four decades. Depending on the waste composition, there is need to formulate the cement waste matrix appropriately to ensure adequate compressive strength and chemical durability. This has been achieved by using different additives/backfill materials during the cementation process with cements for example Ordinary Portland Cement (OPC) and Slag Based Cements (SBC). Backfill materials studied include vermiculite and bentonite. They were evaluated for sorption characteristics, particle size distribution, water equilibration, etc. They were incorporated in the OPC-CWP (Cement Waste Product) with various waste compositions. The composition developed for ILW generated during reprocessing and during spent solvent hydrolysis were successfully adopted on a plant scale. Some of the compositions which are being developed are also in the process of being adopted in-plant. The long-term evaluation study of the CWP was carried out at actual site conditions where CWP in carbon steel drum, plastic drums and bare CWP were disposed in 2001 and removed in 2010: parameters including compressive strength and release of activity to the soil were measured. (author)