11 Oct (NucNet): French nuclear regulator ASN said on 10 October 2018 that it had authorised state-controlled utility and nuclear operator EDF to commission and use the reactor pressure vessel in the Flamanville-3 EPR nuclear reactor under certain conditions.
ASN said the authorisation was based on conclusions published in October 2017 and subject to the implementation of a test programme and specific controls during the operation of the RPV.
In April 2015, ASN, EDF and RPV manufacturer Areva – since restructured and renamed Orano – revealed that tests had shown higher than expected carbon segregation in RPV material samples, indicating a possible manufacturing flaw and potentially affecting the vessel’s ability to withstand the propagation of cracks.
The tests followed earlier chemical and mechanical examinations on forged steel parts representative of the RPV, which showed the carbon segregation phenomenon was higher than expected in a certain area.
Earlier this month ASN said faulty weldings at the Flamanville-3 EPR, under construction in Normandy, northern France, may need more repairs than originally estimated and EDF will have to carry out a quality audit of materials it is using for the plant.
In July, problems with the weldings forced EDF to delay the start-up date for the plant to the second quarter of 2020 and announce an increase in the cost of the project to €10.5bn. An estimate of the cost in July 2011 was €8bn.