Commercial operation of the EPR at unit 3 of Finland’s Olkiluoto NPP (OL3)  has been further delayed and is now expected to begin in September 2019, Teollisuuden Voima Oyj (TVO) announced on 13 June. Commissioning tests are taking longer than planned.

Under the previous schedule provided by the Areva-Siemens consortium, fuel loading was projected for later this year with grid connection taking place in December ready for electricity production in May 2019.

Hot functional testing of OL3 took place between December 2017 and late May. However, in April, TVO said it was waiting for "an overall rebaseline schedule" from Areva-Siemens "due to some delays in the hot functional testing phase". TVO has now said the hot functional tests took 50 days longer than planned. 

TVO said that "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." 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.

"The hot functional testing has now been successfully completed and the schedule for the next phases has been defined," noted Jouni Silvennoinen, TVO's OL3 project director. "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."

Construction of the first-of-a-kind EPR at OL3 began in 2005 under a turnkey contract signed with TVO in late 2003 for completion in 2009, but the project has suffered various delays and court battles. After a long-running court dispute, which was settled in March, Areva agreed to pay TVO €450m for cost overruns and the delays. OL3 will be Finland’s fifth and largest nuclear reactor and provide about 10% of its power needs.
China’s Taishan 1, which also experienced delays, is now expected to be the first EPR to begin operation, later this year, having achieved criticality on 6 June. The similarly delayed EPR at France’s Flamanville 3, is likely to be the second to begin operation toward the end of this year.

Photo: Primary circuit rinsing was carried out at Olkiluoto 3 in October 2016 (Photo: TVO)