The outage of Olkiluoto 3, Finland's newest nuclear reactor which is currently offline for maintenance, is being extended by six days due to technical problems, operator Teollisuuden Voima (TVO) announced on Sunday.
The facility was shut down for its first round of annual maintenance on 2 March, according to the firm, which added that around 1,100 professionals were involved in the effort.
The firm's other two reactors, Olkiluoto 1 and 2, were generating electricity at normal levels of approximately 1,780MW, the company said.
Maintenance on OL3 is now scheduled to be completed on 4 May. The reactor was put into service just over a year ago, following constrution delays of 14 years.
The scheduled break was originally due to end on 8 April.
When the maintenance was set to begin last month, TVO noted that in its first years, OL3 will operate with annual maintenance breaks, but that over time, the gaps between those breaks will increase.
Last year OL3 generated 1,600MW — accounting for more than one-tenth of Finland's electricity.