Regulator concludes Finnish EPR can operate safely

Tuesday, 26 February 2019

TVO submitted its 130,000-page application to the Finnish Ministry of Employment and the Economy (TEM) in April 2016. The application contained information on, among other things, the technical and operational safety principles, arrangement for nuclear waste management, and details of TVO's expertise and financial position.

In addition to seeking approval to operate Olkiluoto 3 for an initial 20-year period (from the beginning of 2018 to the end of 2038), TVO's application also seeks permission to use the existing on-site interim storage facilities for the used fuel and other radioactive wastes that will be generated by the unit over this period. The application does not concern the use of final disposal facilities for nuclear wastes.

The application has been reviewed by Stuk, as well as several ministries and certain other authorities and communities. Stuk has now given its overall safety assessment for the application, while the others will submit statements to TEM. The Finnish government will make a decision on TVO's application based on the ministry's recommendations.

In a statement yesterday TEM, Stuk said it has "assessed that the operations intended by the licence applicant are safe and meet the requirements laid down in the applicable legislation". It added, "Stuk has found no reasons that would prevent the granting of the licence in accordance with the application until 2038."

Stuk said: "While supervising and preparing the safety assessment, Stuk has assessed, besides the technical and structural safety, also the preparedness of TVO's organisation and employees to operate the plant safely."

Stuk's safety assessment has concluded that the plant has been constructed to be safe and that TVO is able to operate it safely. Minna Tuomainen, Stuk's project manager for the OL3 project, said, "In brief, safety means here that the use of nuclear energy does not cause injury to people, or damage to the environment or property."

She noted, "All supervision is based on legislation and more specific regulations and guidelines laid down in it. At this point, we can state that the plant and TVO, the organisation operating it, meet the Finnish safety requirements."

As a condition of the licence, Stuk requires TVO to perform a periodic safety assessment on the plant by the end of 2028 and submit it for Stuk's approval.

Preparations for the start-up of Olkiluoto 3 are progressing. Stuk noted that it will closely monitor work after the operating licence is granted. For fuel loading, TVO still requires a separate authorisation from Stuk.

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 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.

Stuk said that work to suppress the pressuriser surge line vibration is one area to be supervised and inspected before fuel loading. It noted technical solutions exists for fixing this issue.

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. Under the latest schedule, fuel will now 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.

In December, unit 1 of the Taishan plant in China's Guangdong province became the first EPR to enter commercial operation. Taishan 2 is scheduled to begin commercial operation 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.