Olkiluoto nuclear power plant in Eurajoki. Photograph: Greenpeace Finland

“At the moment, the situation is stable,” said Petteri Tiippana, director-general of the Radiation and Nuclear Safety Authority (STUK), in a press conference related to the disturbance at Olkiluoto 2 nuclear power plant on Thursday afternoon in Eurajoki, western Finland.

The disturbance occurred at 12:22 in the afternoon. According to Teollisuuden Voima Oyj (TVO), the energy company that operates the unit, the main steam line’s isolation has been triggered and the containment has been isolated. “An automatic reactor scram has occurred at the plant,” the company noted in a statement.

During the reactor scram, the plant has operated as planned, and according to TVO, a cold shutdown is not necessary.

TVO noted that there is no release from the plant. “No harm has been caused on people or the environment,” the company concluded.

The cause of the disturbance is being investigated.