We have a solution for final disposal of spent nuclear fuel

Posiva has resolved final disposal in a safe manner, thus enabling the operation of nuclear power plants in Finland and in the world also in the future. The solution comprises the final disposal concept, the complex comprising the encapsulation plant and the final disposal facility, and the final disposal process.

Ms. Tiina Jalonen, Senior Vice President, Development, for Posiva, says that the future outlook is promising.

- The safety case compiled for Posiva's application for the operating licence is the outcome of more than 40 years of research and demonstrates the safety of final disposal. The review procedure of the operating licence application is estimated to proceed so that Posiva will be in a position to start the final disposal operation in mid-2020s, Ms. Jalonen explains.

Geological final disposal deep in the bedrock is the method which, of the studied alternatives for final disposal, offers the best solution for isolating the high level radioactive spent fuel from the biosphere, i.e., from the living environment of people and the rest of organic nature. In Olkiluoto, the bedrock is one of the oldest and most stable in the world and the conditions of the bedrock have also in other respects been shown to be accommodating for the engineered barriers of the final disposal system, particularly for the canister. The bedrock areas with the highest integrity are determined based on rock suitability classification for drilling of the deposition holes.

Safety is a prerequisite

Spent nuclear fuel must be isolated from the living environment for a very long period of time. It takes hundreds of thousands of years for radioactivity to be reduced to a level where it is insignificant to the safety of the living environment. For this reason, the key to final disposal is the long-term safety of the solution and that is assessed and demonstrated with the safety case.

According to the international definition, the safety case refers to all technological and scientific materials, analyses, observations, trials, tests and other proof used to justify the reliability of the assessments made of the long-term safety of final disposal.

- The more than four decades of research work is transformed into a detailed description of the geological final disposal solution, analysing different evolutionary paths and demonstrating the safety of final disposal in the conditions of Olkiluoto bedrock, Ms. Jalonen continues.

The safety case takes account of the various changes occurring in nature over the long term, such as possible earthquakes in the far future and future ice ages up to a timeframe of a million years.

Text: Pasi Tuohimaa, photo: Natalie Kylliäinen

Read the nwes, "Posiva submits application for operating licence for encapsulation and final disposal facility of spent nuclear fuel":
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