Vitrification of UK intermediate level radioactive wastes arising from site decommissioning : property modelling and selection of candidate host glass compositions

Vitrification was considered as a potential treatment option for four types of radioactive wet intermediate level waste (ILW) arising from decommissioning of a UK Magnox nuclear power station. Some of the ILWs under consideration were eminently suitable for vitrification as they consisted largely of SiO2, MgO, Fe2O3, Na2O, Al2O3 and CaO. However, the high organic and sulphur contents of some of the ILWs, particularly spent ion exchange (IEX) resins, presented a number of challenges. Here we discuss the ILWs concerned and the property and processing requirements for suitable glass host materials. A total of 80 glass compositions was surveyed and a combination of measured and modelled properties and processing requirements was used, on the basis of the property selection criteria, to select suitable candidate glass compositions for detailed study in laboratory-based trials.