Finland is a pioneer of final disposal of spent fuel. No other country has yet reached the implementation phase of final disposal. Many countries using nuclear power have final disposal facilities for low- and medium-level waste, but final disposal of high-level spent nuclear fuel has not yet been launched anywhere.
The final disposal solution of spent nuclear fuel has been planned in Finland with great detail. Posiva has made decisive progress towards the implementation of final disposal, i.e. the production phase, according to the planned schedule, as there is no desire to pass on the decision to future generations.
The final disposal solution includes
- The final disposal concept, which includes methods for the safe implementation of final disposal. These include the engineered release barriers, i.e. the final disposal canister, buffer bentonite, tunnel backfill and plugs, and the natural release barrier, i.e. the Olkiluoto bedrock.
- The encapsulation and final disposal entity. This consists of two nuclear waste facilities: the above-ground encapsulation plant and the disposal facility in ONKALO®. The disposal facility, for one, consists of the actual repository and other underground facilities (access tunnel, vertical shafts). In addition, the disposal facility includes above-ground auxiliary buildings, such as the ventilation, lifting equipment and tunnel buildings.
- The deposition process wherein spent nuclear fuel is transported from the interim storage to the encapsulation plant for packaging in a disposal canister and for transfer to the repository at the depth of over 400 m. On a global scale, unique technological solutions have been developed for the work phases of the process.
The actual production phase is preceded by the EKA project, which means concisely that Posiva is the first in the world to implement geological final disposal. The project is an investment of approximately EUR 500 million.
The EKA project is an important international trailblazer, as it includes the construction of the facilities used in final disposal, the preparation of technology and the application process for the operating licence. In the EKA project, the encapsulation plant is constructed and commissioned, the technical building systems are installed in ONKALO, the first five deposition tunnels are excavated, the supply chains for the canisters and bentonite clay are prepared and the final disposal activities are started in one tunnel. In the project, Posiva demonstrates that final disposal works as planned.
In addition, the interim storage for spent fuel and the repository for low and intermediate-level radioactive waste (VLJ repository) are located in Olkiluoto. In the future, dismantling waste generated by the dismantling of the plant units will also be placed in the facilities to be excavated in connection with the VLJ repository. The solutions related final disposal have been planned and scheduled to the end.