OL3 is an EPR (European Pressurized Water Reactor) that utilizes technology based on plants commissioned in France and Germany. The 1,600-MW unit is located at the western end of Olkiluoto island, next to OL1 and OL2, which are 890-MW units connected to the Finnish national grid in September 1978 and February 1980, respectively.

Olkiluoto 3 nuclear power plant

OL3 was ordered as a turnkey delivery from a consortium formed by AREVA GmbH, AREVA NP SAS, and Siemens AG. The construction contract was signed on Dec. 19, 2003. However, the plant’s construction license was not issued until Feb. 7, 2005, nearly 14 months later. Construction officially began on Aug. 11, 2005, with the expectation that OL3 would deliver power to the grid by 2009.

Yet, delays ensued nearly from the beginning of the project. In TVO’s 2005 Annual Report, President and CEO Pertti Simola wrote: “The OL3 project at Olkiluoto progressed to the actual construction stage. The preparatory work at the construction site, which was the responsibility of TVO, was completed at the start of the year, and the site was handed over to the plant supplier as planned. The plant supplier’s design work, subcontracting and the manufacture of equipment and components continued on a wide front. However, not every element of the project progressed according to schedule, although the aim is still that the unit will produce electricity in 2009.”

Among the “main reasons for delay” noted in a presentation given by Jukka Laaksonen, director general of Finland’s Radiation and Nuclear Safety Authority (STUK), in 2010, were:

• Too ambitious original schedule for a plant that is first of its kind and larger than any NPP built earlier.

• Inadequate completion of design and engineering work prior to start of construction.

• Shortage of experienced designers.

• Lack of experience of parties in managing a large construction project.

• Worldwide shortage of qualified equipment manufacturers.

Now, more than 12 years after those findings were issued, work continues. In December 2021, STUK granted TVO permission for making the reactor critical and conducting low power tests, after which the startup of OL3’s reactor took place. On March 12, the unit was connected to the national grid at a power output of 103 MW. On March 30, STUK granted TVO permission to increase OL3’s power level to 60% and carry out new power tests at power levels between 30% and 60%. The test production phase was expected to last about four months, with OL3’s power output gradually increased to 1,600 MW.

However, on Wednesday, TVO reported: “Foreign material detached from the steam guide plates was found in the turbine’s steam reheater in May 2022, which requires inspection and repair work. According to investigations from the plant supplier, the repair work will last until the end of July. The plant unit’s test production programme and electricity production can only be continued after the completion of this repair work.”

TVO said it has reserved additional time in the schedule for the plant unit’s upcoming tests and analyses based on previous experiences from the test production phase. The company expects the test production phase will be completed in December 2022, which is when it said the unit’s regular electricity production will start.