Cold functional tests have begun at unit 3 of Finland’s Olkiluoto NPP (OL3), Teollisuuden Voima Oyj (TVO) announced on 12 June. “The main purpose of the tests is to verify the leak-tightness of the primary circuit, a TVO statement said. “ The cold, functional testing stage will take about four weeks, and dozens of tests are to be carried out at different pressure levels. Main coolant pumps will be started for the first time. The pressure is increased gradually in the reactor coolant system to a maximum value significantly exceeding the normal operating pressure.”
TVO added that this was “an important step in plant commissioning” and hot functional tests scheduled for autumn will be the next significant milestone. “Once this stage has been...completed, OL3 will fulfil the preconditions for the granting of the operating licence in early 2018. There are still several significant milestones to be met before the start of the regular electricity production at the end of 2018, OL3 Project Director Jouni Silvennoinen, noted.
TVO applied for an operating licence for OL3 to the Ministry of Employment and the Economy in April 2016 and expected to obtain the licence by the end of this year, after which nuclear commissioning will begin. OL3, An EPR being built by an Areva-Siemens consortium is now some nine years behind the original schedule and significantly over-budget.
Construction of Olkiluoto 3, which began in 2005, has been plagued by delays and is now nine-years behind schedule. In 2009, Siemens sold its shares in Areva NP – Areva's reactor construction company – to Areva, changing its status from the primary contractor to a subcontractor. In September 2014, Areva announced that the unit was on track for completion in mid-2016. However, costs have increased from the original estimate of $3.3bn to $9.3bn. Fuel loading is now expected in spring 2018 for a start up later that year.
Photo of the Olkiluoto nuclear plant, with Unit 3 on the left (Credit: TVO)