EDF Energy on 10 April warned the €10.5bn ($13bn) European Pressurised Reactor (EPR) unit under construction at unit 3 of the Flammanville NPP in France could fall further behind schedule and over budget, after inspections last month revealed problems with welding on pipes. The inspection, a regulatory requirement before start-up of the unit, includes examination of the welds of the primary and secondary systems and allows an initial “reference state” to be established for the plant before its entry into operation.
EDF said the first quality deviation in the welding of the main secondary system was detected on 21 March during the initial comprehensive inspection. EDF added that it had discovered “quality deviations” on 150 welds in a system used to transport steam to the turbines adding that it was performing further checks to see what work would be needed to satisfy the safety requirements of the Autorité de Sûreté Nucléaire (ASN) and would report back in May. In February EDF had said some weldings on Flamanville 3’s secondary cooling circuit did not meet specifications, but the issue would not affect safety or the schedule to start up the plant at the end of 2018.
EDF said in a statement: “Following the current checks and the licensing process by the ASN, EDF will be able to specify whether the project requires an adjustment to its timetable and its costs.” The plant is already three times over its original estimates and several years late. The reactor was originally expected to start commercial operation in 2013 but it is now uncertain whether Flamanville 3 will be operational by the end of 2019. The loading of nuclear fuel is scheduled for the end of the 2018.
Construction of the 1,650MWe unit began in December 2007. The dome of the reactor building was put in place in July 2013 and the reactor vessel was installed in January 2014. Cold functional tests - which verify the leak-tightness of the primary circuit - began at Flamanville 3 on 18 December and were completed on 6 January. Testing of the reactor building to confirm its airtightness was completed on 3 April. Hot functional tests are due to start in July.
Delays have also plagued the first-of-a-kind EPR being built at unit 3 of Finland's Olkiluoto plant (OL3). Construction began in 2005 and has seen several revisions to its start-up date. In October, the schedule for start-up of OL3 was again revised from the end of 2018 to May 2019. The unit began functional hot tests in December. Two EPR units are also under construction at the Taishan NPP in China. Taishan 1 began construction in 2009 and is expected to start up later this year, followed by Taishan 2 in 2019. These units have also experienced delays.
