[en] The activities of the INR concentrate on problems in nuclear technology, especially on problems encountered in the development of sodium-cooled fast reactors. Most of the work is carried out under the roof of projects in cooperation with other institutes or industrial research groups. The studies performed within the fast-breeder project (PSB) relate to reactor physics, design data and safety problems of fast reactors. The environmental impacts of nuclear reactors in case of accidents are investigated by the Institute within the framework of the nuclear safety project (PNS), whereas the problems to be studied for the reprocessing project (PWA) relate to the activity inventary and to instrument development. Another main field of interest is nuclear safeguards, the Institute being concerned with the isotope correlation technique and its application. For the fusion reactor technology project, the research work carried out by the Institute deals with fusion techniques using inertial confinement. (orig./HP)