This books covers topics on the immobilisation of radioactive waste in glass composite materials.Background on radioactive waste and current immobilisation route is included briefly. Contents are focussing on the recent approach of utilising glass composite materials to immobilise low radioactive waste,mainly ion exchanger e.g. natural zeolite;clinoptilolite.The effects of waste loading on a glass composite materials immobilising simulated spent ion exchanger are made the main highlight. This is due to its relevancy in understanding the material-processing and performance relationship in developing wasteform for radioactive waste. Sintering mechanisms and Percolation Model is also described in explaining the behaviour and performance of a glass composite wasteform.