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.