Glass composition development for immobilisation of legacy nuclear wastes

Glasses have been shown to be suitable immobilisation matrices for high level wastes arising from nuclear fuel reprocessing as they reduce waste volume and can give chemically and mechanically durable wasteforms. Currently borosilicates glasses are the favoured compositions and are used globally for high level wastes and some intermediate level wastes. However there are a range of legacy wastes for which the currently used borosilicate glasses are not suitable. This project will focus on specific legacy waste streams and developing suitable, durable glasses for the immobilisation of these waste streams. The project will involve significant glass compositional development, coupled with structural and durability studies on the glasses developed.

Glass composition development will involve extensive glass melting using our specialist glass melting facilities. Characterisation techniques to be used will include chemical and thermal analysis, electron microscopy, Raman, infra-red and Mössbauer spectroscopies. Particular attention will be paid to the incorporation of the simulant radioactive materials in the glass. Durability testing will involve recognised international standards such as PCT and MCC-1 enabling both rates of alteration and the alteration layers on the glass surface to be studied. The emphasis will be on a) developing practically useful vitreous wasteforms and b) understanding the mechanisms of waste incorporation and glass durability for the glasses developed.

Past projects in this area have looked at the incorporation of waste containing challenging anionic species, the immobilisation of graphitic wastes and the immobilisation of high soda-containing wastes. For more details of the specific projects currently available please contact [Email Address Removed]