[Machine Translation] Irregularities at Creusot-Forge: a widespread practice that affects the entire nuclear fleet. The discovery of anomalies in the steel composition of the EPR caps produced quality audits and a review by the manufacturer, Creusot-Forge. On 25 April 2015, Areva, the owner of the forge, informed the ASN of the discovery of “barred files”, that is to say marked by two bars in order to indicate that they had to remain internal. Of the 430 “barred files”, 283 are related to nuclear equipment. The review of the “barred files” carried out during the year 2016 led to the discovery of 87 irregularities for equipment of the French nuclear fleet in operation. The list was published by the ASN. The most serious case concerns a steam generator at Fessenheim 2 which was shut down on 16 June 2016. The test certificate for this generator has been suspended since 18 July 2016 and the reactor is still stationary. See our timeline. According to the ASN, steam generators are particularly important safety equipment because they contribute to the cooling of the reactor core and the containment of radioactive substances. In 2008, during the forging of the lower ferrule in question, Creusot Forge decided not to cut one of the two ends of the ingot, called “mass”, because the length was too short, but continues manufacturing. The major part of this is therefore present in the final part, which can lead to the presence of inclusions in the steel and to a local chemical composition of the material which can degrade its weldability, its aging and its mechanical properties.
Transparence Nucleaire 7th Oct 2017 read more »
