In February 2005, the Finnish government gave its permission to TVO to construct a new nuclear reactor, making Finland the first Western European country in 15 years to order one.
The construction of the unit began in 2005.
The start of commercial operation was planned for 2010, but has been pushed back several times.
As of August 2020, the estimate for start of regular production is February 2022.

Olkiluoto 3 is the first EPR, which is a type of third generation PWR, to have gone into construction.
It will have a nameplate capacity of 1600 MW.
Japan Steel Works and Mitsubishi Heavy Industries manufactured the unit's 526-ton reactor pressure vessel.

At the start of construction, the main contractor was Areva NP (now Framatome, after the sell-off mentioned below), a joint venture of Areva and Siemens.
However, in 2009, Siemens sold its one-third share of Areva NP to Areva, which is now the main contractor.
Siemens remained on the project as the subcontractor with the main responsibility for constructing the turbine hall.
Areva sold its majority stake in Framatome (previously Areva NP), its nuclear reactor and fuel business, to Électricité de France.

According to TVO, the construction phase of the project would create a total of about 30,000 person-years of employment directly and indirectly; that the highest number of on-site employees has been almost 4,400; and that the operation phase would create 150 to 200 permanent jobs.
In February 2005, the Finnish government gave its permission to TVO to construct a new nuclear reactor, making Finland the first Western European country in 15 years to order one. The construction of the unit began in 2005. The start of commercial operation was planned for 2010, but has been pushed back several times. As of August 2020, the estimate for start of regular production is February 2022.
Olkiluoto 3 is the first EPR, which is a type of third generation PWR, to have gone into construction. It will have a nameplate capacity of 1600 MW. Japan Steel Works and Mitsubishi Heavy Industries manufactured the unit's 526-ton reactor pressure vessel.
At the start of construction, the main contractor was Areva NP (now Framatome, after the sell-off mentioned below), a joint venture of Areva and Siemens. However, in 2009, Siemens sold its one-third share of Areva NP to Areva, which is now the main contractor. Siemens remained on the project as the subcontractor with the main responsibility for constructing the turbine hall. Areva sold its majority stake in Framatome (previously Areva NP), its nuclear reactor and fuel business, to Électricité de France.
According to TVO, the construction phase of the project would create a total of about 30,000 person-years of employment directly and indirectly; that the highest number of on-site employees has been almost 4,400; and that the operation phase would create 150 to 200 permanent jobs.
Olkiluoto Nuclear Power Plant