Background and broader context of NF-Pro
Nuclear power constitues an important share in the energy mix of the European Union. At present, 32 percent of the electricity produced in the EU comes from nuclear power. Nuclear power makes a positive contribution to the energy-independency of the EU and produces only a negligible quantity of CO2. Nonetheless, the future of nuclear energy remains uncertain since the management of long-lived and high-level radioactive waste and spent nuclear fuel is one of the most challenging issues regarding nuclear power generation.
In the 1970's, national and international research programmes were set up with the purpose of investigating various options for the long-term management of radioactive waste. Today, broad consensus exists in the scientific community on deep (geological) disposal as the ultimate solution for the safe management of the radioactive wastes. Through geological disposal, radioactive waste is isolated from the biosphere by multiple engineered and natural barriers.
Countries like Belgium, Finland, France, Germany, Sweden, Switzerland and the United Kingdom have established extensive radioactive waste management programmes and have conducted detailed investigations in underground research laboratories and facilities. Data from these studies are applied in determining the expected safety performance of future geological repositories for radioactive waste disposal.
Despite some differences in the national programmes, potential repository systems all have common elements and are based on well established technologies.
Radioactive waste
Spent fuel from nuclear power reactors can be disposed of without separation of radionuclides or additional treatment. This approach is known as direct disposal. Alternatively, the spent fuel can be reprocessed, this means chemically treated prior to disposal with the aim of recycling fissile radionuclides and separating fission products in view of incorporating these into a stable solid matrix like glass (vitrified waste).
Geological disposal
Radioactive waste arises from a wide range of nuclear applications. In terms of volume and concentrations of activity, radioactive waste from nuclear power production is most important while medical applications, R&D and industrial processes give rise to relatively small amounts of waste with comparatively moderate levels of activity.
During the last decades, a substantial amount of scientific effort has been deployed to finding a permanent and sustainable solution to the safe management of radioactive waste. Today, broad consensus exists in the international scientific community on geological disposal as the most effective option for the long-term management of high-level radioactive wastes. Accordingly, countries depending on nuclear power have developed national programmes focussing on land based disposal in various types of host rock such as granite, clay and salt. Repository designs for deep repositories that are currently under investigation in the EU Member States are all based on the multiple barriers concept. In this concept, the disposed waste is enclosed by a succession of man-made barriers in the near-field and the natural host rock in the far-field.