Final disposal of low and intermediate level wastes from nuclear power plants in Finland

Finland produces 35-40% of its electricity from its four nuclear power plant units. The plant utilities are responsible for management of the radioactive waste, including its final disposal. LLW and ILW are presently treated and stored at the power plant sites; the amounts of waste are moderate. The suitability of the bedrock of the power plant sites for final disposal was assessed in 1982, and the principle of disposing of LLW and ILW at the sites was approved. During 1983-1985 the site investigations were complemented by additional field investigations, more detailed repository design and related safety analyses. The location and layout of the repositories at both sites are determined on the basis of geological conditions. The Loviisa repository consists of a cavern for solidified waste and tunnels for dry waste. The Olkiluoto repository consists of a waste cavern with two silos. Provisions have been made for later enlargement of the repositories for decommissioning waste. After operation the repositories will be backfilled and sealed. The safe final disposal will be based on the principle of multiple barriers. The performance of each disposal system will be evaluated with a comprehensive safety analysis and will be expressed in terms of the total health risk for various release scenarios. Results are to be presented to the authorities in preliminary safety analysis reports by the end of 1986. Construction of the repositories will be started during 1988, in which case the repositories could be commissioned by the end of 1992. (author)