Earlier this year the plant supplier, Areva-Siemens, said it would update the schedule because modification outage work was not progressing as expected.
Regular electricity production was previously planned to start in January 2020.
According to the new schedule, announced today by TVO, nuclear fuel will be loaded into the reactor in January 2020. The first connection to the grid will take place in April 2020 and the start of regular electricity production, or commercial operation, will take place in July 2020.
According to a commissioning programme for Olkiluoto-3, the unit will produce 1-3 terawatt hours at various power levels during a test period, which will begin with connection to the grid and end with electricity production.
Construction of Olkiluoto-3, a 1,600-MW EPR unit, began in August 2005 and is about nine years behind schedule. In March the Finnish government granted an operating licence for the unit.
In February TVO said construction work was mostly complete, with electrical, automation and mechanical installation still partly in progress.
In March 2018 TVO signed an agreement with Areva-Siemens over costs and losses caused by delays to the project. The settlement included compensation of €450m to be paid in two instalments.
