Radioactive waste management: the need for multiple barriers

Isolation criteria for the disposal of high-level radioactive waste are critically examined. The results indicate that the essential period for isolation of high-level waste is about 1,000 years. Multiple barriers, such as a solidified, leach-resistant waste form (i.e. fixation in glass), a corrosion-resistant outer container, and a stable geological formation, which limit the transport of radioactivity into the human food-chain are recommended. The multiplicity of barriers allows for the unlikely event of failure in one or two of the barriers while still providing adequate isolation of the waste.