Safety of Nuclear Waste Management

In the interest of safe nuclear waste management, research work is conducted within the KIT Energy Center about the immobilization of high-level radioactive waste, reduction of radiotoxicity, and long-term safety of nuclear repositories. For safe final storage, liquid radioactive high-level waste of the kind arising from reprocessing processes of spent nuclear fuels is solidified in a glass matrix. For this purpose, Karlsruhe scientists have developed a vitrification technology which is used internationally to immobilize high-level radioactive fission product solutions. When it will be possible to separate long-lived radionuclides from radioactive waste (partitioning) and convert these nuclides into short-lived or stable products in suitable facilities (transmutation), the long-term radiotoxicity of the residual waste can be reduced decisively. Within the framework of international cooperation, the KIT Energy Center investigates the technical feasibility of partitioning and transmutation and the advantages of this technology in the disposal of long-lived radionuclides.

Disposal of radioactive waste in deep geologic formations is aimed at to isolate waste from the biosphere on a long-term basis. KIT scientists are developing the principles of a scientifically based demonstration of long-term safety. The actinides and long-lived fission products responsible for the radiotoxicity potential of high-level radioactive waste for hundreds of thousands of years are in the focus of research. The KIT scientists study the geochemical-physical processes causing release or retention of radionuclides under repository conditions. This fundamental work is closely connected with application-oriented studies of real radioactive waste, and with studies under near-natural conditions, for instance in underground laboratories in Sweden, Switzerland, and France. The research results are used to evaluate, select and study repository sites up to the point at which geochemically reliable proof of long-term safety can be produced. On the KIT Campus North, Karlsruhe scientists have sophisticated experimental facilities available, such as controlled areas, actinide laboratories, and hot cells which, combined with analytical and spectroscopic methods for studying radioactive materials, are unique in the world.