Permanent safe solutions are needed for isolating from the human environment the radioactive waste resulting from the operation of commercial nuclear power plants, as well as long-lived wastes from other nuclear applications in research, industry and medicine. The only option currently regarded by the scientific and engineering community as viable is deep disposal in stable geologic formations. National and international repository concepts are being developed for this option. A further – and more urgent – challenge is presented by the need to deal with the many tonnes of plutonium and highly enriched uranium, which have arisen from dismantling of nuclear weapons. Most of these materials may be converted into fuel for nuclear reactors. The deep disposal of the resultant spent fuel along with conditioned plutonium is a key economic and security issue for the world. There is a common solution to the challenges of ensuring long term safety for spent fuel and of preventing weapon grade materials being illegally diverted and misused. Deep geologic repositories are the answer. The paper describes the specific engineering, geological, hydrogeological and geotechnical challenges involved at each phase in the development of a geologic repository. It then briefly considers the particular case of Australia. We point out that there is a requirement for geologic disposal of limited quantities of Australian wastes, that this could be accomplished in a national or international framework and that relevant expertise is available for repository implementation in Australia.
Long-lived radioactive wastes are produced primarily in nuclear power generation – but also in other applications such as medical isotope production, medicine, research and industry. The isolation times required to ensure safety are in some cases extremely long (over 100,000 years) - although never infinite, as for some chemo-toxic wastes.