The start date of Finland's biggest nuclear project Olkiluoto 3 EPR is being pushed to late 2018, which is almost a decade later than the proposed initial timeline.
Areva-Siemens, the consortium constructing the reactor, has said that disagreements with its client Teollisuuden Voima (TVO) over the plant's instrumentation and control (I&C) system has been the reason for the delay.
The project has been hit by delays several times previously in addition to surging costs and disputes between Areva-Siemens and TVO.
The country aims to achieve energy self-sufficiency once the Olkiluoto 3 project is commissioned.
The 1,600MW plant began construction in 2005 and was to have commenced operations in 2009.
According to the new timelines, the project construction will be completed by the third quarter of 2016 and will commence operations in the last quarter of 2018.
Areva urged the owner of the plant, TVO, to take an active role in the project. TVO said the delay was hard to accept, as much of the project was complete.
TVO's owners include Finnish paper firms UPM and Stora Enso and utility company Fortum.
Reuters quoted TVO's project head Jouni Silvennoinen as saying: "The delays are because the planning of the plant has taken needlessly long.
"We haven't examined the supplier's detailed schedules yet, but our preliminary view is that we could do better (than 2018)."
TVO has already received a general license to develop Olkiluoto 4; however, the firm has sought a five-year extension to the permit from the government.
Olkiluoto 3's construction costs were initially estimated to be around €3.2 bn and although TVO has not released the updated figures, it is believed to have increased almost double.
In 2013, Areva-Siemens sought a compensation of €2.7bn; to this, TVO submitted a counter claim of €1.8bn.
The International Chamber of Commerce's (ICC) arbitration court is looking into the dispute between the two parties on cost overruns.
Image: The construction site of Olkiluoto 3 EPR in Finland. Photo: courtesy of AREVA.