Start-up of Finnish EPR put back four months

Regular electricity generation at the Olkiluoto 3 EPR in Finland is now expected to begin in September 2019 as commissioning tests will take longer than planned, Finnish utility Teollisuuden Voima Oyj (TVO) announced yesterday. According to the previous schedule provided by plant supplier the Areva-Siemens consortium, production was planned to start next May.

The Olkiluoto EPR, pictured in August 2016 (Image: TVO)

In April, TVO said it was waiting for "an overall rebaseline schedule" from the Areva-Siemens consortium "due to some delays in the hot functional testing phase".

Hot functional testing of the Olkiluoto 3 (OL3) EPR began in December and was completed in late May. These key pre-operational tests ensure coolant circuits and nuclear safety systems are functioning properly before fuel is loaded. They are the first tests at plant-level where the 1600 MWe pressurised water reactor and turbine plant are operated as a whole, although still without fuel. During the tests, the water temperature and the pressure of the primary circuit were gradually increased to the level where they would be during actual operation.

TVO has now said completion of the hot functional tests took 50 days longer than planned. "Based on the findings of the commissioning tests, a comprehensive modification package will be implemented at OL3 over the next few months to update the plant's electrical and instrumentation and control (I&C) systems," the company said. "After the modification works, the necessary parts of the commissioning tests will be repeated and commissioning will continue. In addition, the pressuriser surge line vibrations that delayed the hot functional tests will be corrected before fuel loading."

Fuel loading will begin once a safety assessment of Olkiluoto 3 is carried out by the Radiation and Nuclear Safety Authority and a decision by the Finnish government to issue an operating licence.

The Areva-Siemens consortium has informed TVO that the loading of fuel into the core of OL3 is now expected in January 2019, connection of the plant to the electrical grid in May and the start of regular electricity production in September next year. Under the previous schedule, fuel loading was planned for later this year, grid connection taking place in December, with the start of regular electricity production in May next year.

"The hot functional testing has now been successfully completed and the schedule for the next phases has been defined," said TVO's OL3 Project Director Jouni Silvennoinen. "The whole commissioning is performed with utmost care, without compromise. We will have a modern and safe plant, and its commissioning will strengthen our know-how for the operating phase."

The Areva-Siemens consortium began construction of Olkiluoto 3 - the first-of-a-kind EPR - in 2005 under a turnkey contract signed with TVO in late 2003. Completion of the reactor was originally scheduled for 2009, but the project has suffered various delays and setbacks.

Fuel was loaded into the core of the Taishan 1 EPR in China's Guangdong province in April and that reactor achieved first criticality on 6 June. The unit is later this year scheduled to become the first EPR reactor to enter operation. Fuel loading at the Flamanville EPR in France is scheduled to begin in the fourth quarter of this year.

Researched and writtenby World Nuclear News