The Radiation and Nuclear Safety Authority (STUK) has given permission to nuclear power utility TVO, the owner of the Olkiluoto plant in Southwest Finland, to restart the OL2 reactor again after an automatic emergency shutdown last week.
According to a statement released by the authority, TVO has determined the reasons for the incident and performed the necessary inspections and maintenance work.
OL2 has been in a cold shutdown state since last Thursday after warmer-than-usual water entered the cleaning system of the reactor, causing a momentary peak in the steam line's radiation measurement which triggered the safety systems.
In its statement, STUK admitted that informing the public about the shutdown was too slow. The municipality of Eurajoki, in the immediate vicinity of the plant, was not informed until several hours after the incident.
The reconnection of the OL2 reactor to the grid was delayed a number of times this week, but will proceed later this week, according to TVO.