Onkalohankkeena

Onkalohankkeena, which translates to "The Onkalo Project" in English, refers to the Finnish plan for a deep geological repository for spent nuclear fuel. The project is managed by Posiva Oy, a subsidiary of Finnish nuclear power companies Fortum and Teollisuuden Voima. The chosen site for the repository is Olkiluoto, located on the west coast of Finland, which already hosts two operating nuclear power reactors.

The primary goal of Onkalohankkeena is to provide a permanent and safe solution for the disposal of high-level radioactive waste generated by Finland's nuclear power plants. The repository is designed to be constructed deep underground, within the stable crystalline bedrock of the Olkiluoto island. This depth is intended to isolate the spent fuel from the biosphere for hundreds of thousands of years, the estimated time required for its radioactivity to decay to safe levels.

The construction of the repository involves a multi-stage process, including extensive site investigations, the excavation of access tunnels and deposition tunnels, and the development of specialized handling and sealing techniques. The design emphasizes multiple barriers, both engineered and natural, to prevent the release of radionuclides. These barriers include the spent fuel canisters, the buffer material surrounding the canisters, and the surrounding bedrock itself. Onkalohankkeena represents one of the world's leading efforts in the long-term management of nuclear waste, aiming to establish a precedent for safe disposal.