Annual report 1983

An autonomous OECD/NEA Project relating to the final disposal of highly radioactive waste from nuclear power generation is currently under way in an abandoned iron ore mine at Stripa, in central Sweden. Research is being performed in a granite formation 350 meters below ground. The first phase of the project, scheduled for completion in 1984, consists essentially of three parts: - hydrogeological and geochemical investigations in boreholes down to a depth of 1230 metres below the ground surface, tracer migration tests to study radionuclide transport mechanisms in the rock fractures, and large-scale tests of the behaviour of backfill material in deposition holes and tunnels. The second phase, started in 1983 and is scheduled for completion in 1986. The investigations included in the second phase are: development of crosshole geophysical and hydraulic methods for the detection and characterization of fracture zones - extended tracer experiments in fractured granite, and the sealing of boreholes and shafts, using highly compacted bentonite. The KBS Division of the Swedish Nuclear Fuel Supply Company acts as the host organization, and provides the management for the Project. It is responsible for mine operations and for the procurement of equipment and material for experimental work (G.B.)