Grid connection of Finnish EPR postponed

27 January 2022

The connection of unit 3 at the Olkiluoto nuclear power plant in western Finland to the national grid has been delayed due to an unplanned automatic trip during commissioning tests, operator Teollisuuden Voima Oyj (TVO) has announced.

The Olkiluoto 3 EPR (Image: TVO)

The plant will now be connected to the grid in the first half of February, instead of the end of January as previously expected, TVO said. The expected start of regular electricity production remains unchanged as June.

"At the test production phase of a nuclear power plant, the plant unit and its safety systems are tested to verify that the plant operations comply with design," TVO noted. "The commissioning tests also comprise planned reactor trips."

However, it said an unplanned automatic trip occurred on 14 January.

"The causes leading to the automatic trip and corrective measures have now been dealt with, but they caused a delay in the test production programme," TVO said. "The test production programme is currently proceeding normally."

The Areva-Siemens consortium is constructing the OL3 plant under a fixed-price turnkey contract. They have joint liability for the contractual obligations until the end of the guarantee period of the unit. Construction of Olkiluoto 3 began in 2005. Completion of the reactor was originally scheduled for 2009, but the project has had various delays and setbacks.

The Finnish Government granted an operating licence for OL3 in March 2019. Finland's nuclear regulator, STUK, granted a fuel loading permit in March 2021. Fuel loading was completed on 1 April, at which point an October start-up was envisaged. However, this was postponed to allow for extra turbine overhaul and inspection works by the plant supplier. The reactor reached first criticality on 21 December. Electricity production will start when a 30% power level is reached.

Researched and written by World Nuclear News