Finland's Radiation and Nuclear Safety Authority (Stuk) has given permission for fuel to be loaded into the Olkiluoto 3 (OL3) nuclear reactor in Eurajoki, southwest Finland.
The decision marks the beginning of a new stage in the commissioning of the long-delayed reactor, which has been under construction since 2005.
"This is the most significant step in the commissioning of the plant unit so far. OL3 is one of the world's largest and most modern nuclear power plants. The systems have now been rigorously tested, and we will be able to begin fuel loading soon," said Jouni Silvennoinen, project director for nuclear utility company TVO.
In a statement, Stuk said that the granting of permission to load fuel into the reactor meant that OL3 met safety requirements.
According to Stuk Project Manager Essi Vanhanen, once fuel loading begins, OL3 will be regarded as an operating nuclear power plant.
The process will involve 241 fuel assemblies comprising 128 tons of uranium being loaded into the reactor's pressure vessel. The fuel originally arrived onsite in 2018, plant operator TVO said.
The company said regular electricity generation at the plant would begin in February 2022.
The OL3 reactor has been beset by delays. Originally intended to start generating electricity in 2009, the reactor’s start date has been pushed back repeatedly by issues including faulty components and safety tests. The delays led to lawsuits between the plant operator TVO and its builder, the French firm Areva.
Once completed, the OL3 reactor is expected to produce around 14 percent of Finland’s electricity.
Its sister reactor, Olkiluoto 2, made headlines in December 2020 after an emergency shutdown caused by warm water entering the reactor's cleaning system.