French nuclear group EDF has confirmed it will carry out further tests on the reactor vessel at the heart of the new Flamanville-3 nuclear plant in Normandy, the same reactor model as the one planned for Hinkley Point in Somerset. In a statement the firm conceded that problems in the steel casing for one reactor vessel extended beyond the point they have so far tested. Or, in their own words: “Initial analyses conducted on two parts similar to those at Flamanville 3 have shown that the carbon segregation phenomena extend beyond mid-thickness on one of them.
Energy Desk 14th April 2016 read more »
French electric utility EDF and nuclear equipment manufacturer Areva have recommended to the French nuclear safety authority ASN (Autorité de Sûreté Nucléaire) to extend the testing programme for the 1,600-megawatt Flamanville-3 EPR reactor pressure vessel (RPV) until the end of 2016, the two companies said in separate statements. In April 2015, ASN, Areva and EDF 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 for the RPV, which showed the carbon segregation phenomenon was higher than expected in a certain area. According to Areva and EDF, analyses showed that the carbon anomaly extended beyond mid-thickness in one of the two steel parts under examination – representative for the RPV head and bottom – which required material sampling and related tests to be extended to three-fourths of the thickness of the part concerned. The suggested testing programme extension will therefore include examinations of a third forged steel part with the goal to “strengthen the robustness of the demonstration” of the EPR, EDF and Areva said. The companies said the proposed additional tests will examine 1200 material samples, a two-fold increase in comparison with previous analyses.
Nucnet 14th April 2016 read more »
Areva and EDF’s program for testing the mechanical properties of Flamanville 3’s reactor pressure vessel has been extended. Previously the tests were to be carried out on samples from two forged parts but will now be conducted on three. The French nuclear regulator – the Autorité de Sûreté Nucléaire (ASN) – released information in April 2015 about the discovery of anomalies in the composition of the steel in certain parts of the reactor vessel of the EPR under construction at Flamanville. Chemical and mechanical tests were conducted by Areva in late 2014 on a vessel head similar to that of the Flamanville EPR. These test results “revealed the presence of a zone in which there was a high carbon concentration, leading to lower than expected mechanical toughness values”. Both affected components – the vessel head and the vessel bottom – were manufactured at Areva’s Chalon/Saint-Marcel plant in France.
World Nuclear News 14th April 2016 read more »