The random network structure of glass provides a unique matrix that is particularly suited to incorporating and immobilizing potentially hazardous radioactive and non-radioactive materials. Performance of a wide variety of waste glass systems and their ability to retain hazardous species is excellent when tested under realistic conditions, according to data currently available from characterization studies and leaching tests performed in studies by many different investigators in many countries. In addition to possessing outstanding chemical durability, the durability of nuclear waste glasses generally improves over time. This behaviour has been observed in laboratory tests as well as in field experiments conducted with simulated US HLW glasses buried in granite in Sweden, clay in Belgium, limestone in the UK and salt in the US.
