New delay in start-up of Finnish EPR

Thursday, 29 November 2018

Last month, the plant's supplier - the Areva-Siemens consortium - announced it wanted to update the schedule for completing the unit as commissioning tests were taking longer than planned.

TVO said it has been informed by the Areva-Siemens consortium that fuel will now be loaded into the reactor core in June 2019, with grid connection to take place next October, and the start of regular electricity generation scheduled for January 2020.

Under the previous schedule provided by the plant supplier in June this year, fuel loading was expected in January 2019, grid connection in May and the start of regular electricity production in September.

Hot functional testing of the 1600 MWe pressurised water reactor began last December and was completed in late May, 50 days later than planned. 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 reactor and turbine plant are operated as a whole, although still without fuel.

The delay in completing the hot functional tests was due to vibrations in pressuriser surge line. Based on the test results, TVO said a comprehensive modification package would be implemented at OL3 to update the plant's electrical and instrumentation and control systems.

TVO has now said the commissioning tests of OL3 will take longer than expected and are still ongoing. "The final automation modification package will be implemented and the pressuriser surge line vibrations will be repaired by modifying the pipe support, and the commissioning test will be continued," the company said. "After modifications, the necessary commissioning tests will be repeated and commissioning will continue."

According to the commissioning programme, OL3 will generate 2-4 TWh of electricity with varying power levels during the test programme, which will begin at grid connection and end when regular electricity production starts.

"Although this new delay is disappointing of course, it is important that the whole commissioning is performed with utmost care, without compromise," said TVO's OL3 Project Director Jouni Silvennoinen. "We will have a modern and safe plant, and we are already looking forward to 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.

On 29 June, Taishan 1 became the world's first EPR to achieve grid connection and power generation. It is expected to enter commercial operation later this year. Taishan 2 - which is in the equipment installation phase - is scheduled to begin operating next year.

Construction of the Flamanville EPR began in December 2007, with commercial operation originally expected in 2013. Hot functional tests are now expected to begin before the end 2018. The loading of fuel into the unit's core is expected in late-2019.

Two further EPRs are planned for the Hinkley Point C plant in Somerset, England.