Trial Run of Final Disposal started today in Olkiluoto

30.8.2024

The final disposal of spent nuclear fuel will be tested without actual spent fuel during the upcoming months. The equipment and systems of the final disposal facility will be tested together for the first time in accordance with planned processes during the Trial Run stage that started today. The purpose of the Trial Run is to verify safe final disposal before the start of the actual final disposal operation.

In Finland, the power companies have decided to deposit the spent nuclear fuel produced by the nuclear power plants deep in the stable bedrock for final disposal. Prior to final disposal, the fuel is allowed to cool for about 40 years. In the final disposal facility of Posiva Oy, the fuel is packed in cast iron cannister inserts enclosed in an outer cannister made of anti-corrosion copper. The cannisters are placed in deposition holes drilled in ONKALO® at a depth of about 430 metres and covered with bentonite clay.

In the Trial Run, the operation of the final disposal facility is tested comprehensively, albeit still without the spent fuel. Four canisters will be disposed of in eight metres deep deposition holes bored in the bottom of the 70 metres long tunnel excavated specially for Trial Run of Final Disposal. The final disposal tunnel is then filled with bentonite clay and sealed with a concrete plug. The Trial Run also covers the retrieval of a damaged cannister back above ground.

Finland is the first country in the world where a solution has been developed for the final disposal of spent fuel. The facility features many unique systems and equipment produced as a result of decades of research and now used together for the first time. The Trial Run of Final Disposal can be described as a joint functional test of all the systems and equipment. The Trial Run will take several months.

- Posiva has come a long way to reach this point. The Trial Run of Final Disposal is not only an excellent opportunity for learning and development, but also an extremely demanding showcase of the capabilities of our organisation, says Posiva’s Production Director Karri Osara.

According to Posiva’s President and CEO Ilkka Poikolainen, the Trial Run of Final Disposal that has now been launched is a historical milestone for both Posiva and the whole world.

- Posiva’s operation now takes a significant step toward the start of the actual final disposal operation. This is a momentous occasion also to our employees and cooperation partners, Poikolainen praises.

Posiva Solutions, the subsidiary that markets Posiva’s unique expertise, has offered the global nuclear waste organisations an opportunity to attend and learn about the implementation of safe final disposal in practice. In effect, the Trial Run of Final Disposal plays a significant role in demonstrating the joining of the final link in the sustainable use of nuclear energy, i.e., returning the spent fuel back in the bedrock.


For more information and requests for interviews, please contact:
Pasi Tuohimaa, Communication Manager, tel. +358 40 544 5001

Through these links, you can learn more about Posiva's final disposal activities:
Animation about the final disposal of spent nuclear fuelOpen link in a new tab
Animation about the operation of the encapsulation plantOpen link in a new tab