Finland has successfully completed its first nuclear decommissioning project with the dismantling of the FiR1 research reactor, which operated for over 50 years at the VTT Technical Research Centre premises in Otaniemi, Espoo, near the capital Helsinki.

The decommissioning project was carried out by utility Fortum, which owns and operates the Loviisa nuclear station in Finland, in collaboration with VTT, the reactor’s owner.

The dismantling process, which began in June 2023 and ended in April 2024, marked a significant milestone in Finland’s nuclear industry, said Fortum. VTT received regulatory approval for decommissioning in 2021.

The company handled the full scope of the decommissioning work including planning, preparatory measures, reactor dismantling, waste management and the final disposal of radioactive waste.

Fortum said the project provided significant experience for both Fortum and VTT, particularly in preparing the extensive documentation required for the decommissioning licence. It said the experience will be valuable for future projects.

The decommissioning generated approximately 60 cubic meters of demolition waste, primarily concrete, which will be disposed of in Fortum’s Loviisa nuclear power station’s repository for low- and intermediate-level waste.

Fortum said that given the reactor’s use for research and educational purposes, the amount of decommissioning waste and its associated radioactivity were relatively small.

FiR1 was Finland’s first nuclear reactor. It was of the Triga design with a thermal output of 250 kW.

The reactor began operation in 1962 and was first used by the Helsinki University of Technology. It was permanently shut down in 2015.

According to VTT, after 1999, the FiR1 reactor was used in collaboration with the Hospital District of Helsinki for cancer therapeutic purposes until the treatment provider went out of business in 2012.