Hot functional tests have been completed at unit 3 of Finland’s Olkiluoto NPP (OL3), Teollisuuden Voima Oyj (TVO) said in a statement on 30 May. The tests are part of commissioning process for the EPR reactor and took around five months to complete.
The systems of the 1600MWe Generation III+ pressurised water reactor unit were tested comprehensively, but without the fuel. The temperature and pressure values of the water in the primary circuit were gradually raised to levels reached during operation. TVO said more than 200 tests were carried out at different pressure and temperature levels.
The hot testing followed cold functional tests to confirm whether components and systems important to safety were installed correctly and ready to operate in a cold condition. Cold testing began in June 2017 and took about four weeks to complete. The primary purpose of those tests was to verify the leak-tightness of the primary circuit.
Preparations for fuel loading are now underway, signalling the start of the final stage of the commissioning process, the statement said. TVO has announced OL3 is scheduled to be connected to the grid in December followed by commercial operation in May 2019. Fuel loading will begin after a safety assessment by the Radiation and Nuclear Safety Authority and a decision by the Finnish government to issue an operating licence. TVO expects to start loading the 241 fuel assemblies into the reactor in the autumn.
Photo: The Olkiluoto nuclear plant (credit: TVO)
