Fuel loading delayed at Finnish EPR

Wednesday, 19 June 2019

On 10 April, TVO said the Areva-Siemens Consortium that is constructing the plant will provide a schedule review this month. However, it now says according to the information provided by the consortium the schedule review will be completed in July.

TVO also announced in April that the modification outage work during the first quarter of this year at Olkiluoto 3 "had not been progressed according to the updated schedule issued by the plant supplier Areva-Siemens Consortium in November 2018". The utility said that, based on the information provided by the plant supplier in April, fuel "will not be loaded into the reactor before the end of August".

Hot functional testing of the 1600 MWe pressurised water reactor began in December 2017 and was completed in May last year, 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 the pressuriser surge line. Based on the test results, TVO had said a comprehensive modification package would be implemented at Olkiluoto unit 3 (OL3) to update the plant's electrical and instrumentation and control systems. Suppressing the vibrations is one of the issues TVO must resolve before the regulator will allow fuel loading to proceed.

TVO announced on 23 May that it had started work to install liquid absorbers featuring bitumen to resolve the vibration issue. At that time, the company said installation of absorbers was expected be completed in the early summer.

TVO was granted an operating licence by the Finnish government for Olkiluoto 3 on 7 March. For fuel loading, TVO still requires a separate authorisation from the country's Radiation and Nuclear Safety Authority (Stuk).

The Areva-Siemens Consortium began construction of Olkiluoto 3 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. Under the latest schedule, fuel was to be loaded into the reactor core in June this year, with grid connection to take place in October, and the start of regular electricity generation scheduled for January 2020.

Once it enters commercial operation early next year, OL3 will supply about 15% of Finland's electricity demand.

In December last year, unit 1 of the Taishan plant in China's Guangdong province became the first EPR to enter commercial operation. Taishan 2, which achieved first criticality on 28 May, is scheduled to begin commercial operation later this year. The loading of fuel into the core of the Flamanville EPR in France is expected towards the end of this year. Two EPR units are also under construction at the Hinkley Point C project in Somerset, UK.