Finland’s oldest nuclear reactor, FiR1, located in Espoo, has been retired after operating for 50 years. Commissioned in 1962, this research reactor played a pivotal role in scientific research and supported healthcare applications. Operating at 250kW thermal power, it did not generate electricity or heat for commercial use.

The reactor ceased operation in 2015, initiating a process for decommissioning and dismantling. By 2020, a significant step was achieved as 103 spent nuclear fuel rods, weighing approximately 300kg, were shipped to the United States.

In 2021, VTT secured the decommissioning license, leading to Fortum starting dismantling in June 2023, completing the task by April 2024. Fortum will now manage the final disposal of waste at the Loviisa power plant’s repository for low and intermediate-level waste.

Despite its small size, the FiR1 decommissioning project in Finland is set to serve as a blueprint for future commercial nuclear reactor decommissionings and has enhanced expertise for international use by VTT and Fortum.

Alongside FiR1, VTT collaborated with Finnish partners on the dECOmm project, funded by Business Finland, using it as a testing ground for various applicable technologies. This initiative successfully achieved its goal of exporting technology.

According to Markus Airila, principal scientist at VTT, the dismantling phase proceeded swiftly due to thorough planning and preparation. Leveraging Fortum’s nuclear safety culture and expertise from the Loviisa nuclear power plant ensured the work was completed safely, efficiently, and on schedule, with minimal delays. Safety considerations at Aalto University’s Otaniemi campus were meticulously addressed during site organization and waste transport arrangements.

Demolition waste classified as radioactive is being transported for final disposal at Fortum’s Loviisa nuclear power plant’s repository for low- and intermediate-level waste.

Approximately 60 cubic meters of waste, predominantly concrete, was produced and transported to the Loviisa repository as part of the decommissioning of FiR1. Surrounding the reactor were structures like a six-meter-high water tank and a two-meter-thick concrete shell.

According to Fortum’s project director, Antti Ketolainen, the successful completion of the project underscores their extensive expertise across the entire lifecycle of nuclear facilities. They have applied the same high standards used in operating nuclear facilities to executing decommissioning projects, a capability developed over decades of serving external customers.

The FiR1 project provided valuable lessons and experience that Fortum plans to apply to enhance their operations and support their service business customers. This includes developing decommissioning plans and cost estimates.

The total cost of decommissioning FiR1 amounted to approximately €24 million (AUD$38.7 million), which was pre-funded by the Finnish Nuclear Waste Management Fund.