Irregularities detected at the metallurgist Aubert et Duval: an initial assessment shows there to be no impact on the safety of installations

In December 2018, Eramet (a French mining and metallurgical group) published on its website a report of nonconformities in the quality management system within its Alloys branch, which includes the company Aubert et Duval. This subsidiary manufactures numerous metallurgical products that enter into the composition of diverse equipment items (studs, pump components, pressure equipment, etc.), some of which are intended for the nuclear industry.

The Eramet group informed EDF of this situation on account of the number of potential deviations that could affect the nuclear power plants operated by EDF, and EDF immediately established an inspection plan. This inspection plan was communicated to ASN.

In parallel with this, ASN asked the other basic nuclear installations licensees to check whether any equipment in their facilities having serious implications for safety had been manufactured using materials from the Auber and Duval workshops. This obliged the licensees to question their suppliers to identify the equipment potentially concerned by the observed deviations.

The identified irregularities consisted mainly in inappropriate processing of certain internal anomaly sheets resulting from the manufacturing process, and in modifications of laboratory data. At present, the EDF review is focusing on the verification of the processing of more than 4,500 internal anomaly sheets and the accuracy of more than 700 data items from the laboratories or the metallurgy department. This review at present covers the 2011-2018 period for the laboratory tests and is to be taken back even further. It will continue in 2020.

Over the verification perimeter investigated so far, EDF has found more than 200 deviations requiring specific processing, but concludes that none of the deviations observed renders a metallurgical product supplied by Aubert et Duval unfit for its current use. At this stage of the investigations, the information ASN has received from EDF confirms this analysis.      

Orano, for its part, has asked its subcontractors to check their procurements. The responses are currently being analysed.

The other nuclear licensees have so far not identified any equipment items with safety implications that are concerned by these irregularities.            

The investigations carried out further to the discovery of these nonconformities have revealed the application, within entities internal to Aubert et Duval, of instructions which aimed to modify results in order to render them administratively compliant with the technical requirements. In application of Article 40 of the Code of Criminal Procedure, ASN has reported these practices - which could amount to fraud - to the Public Prosecutor.

ASN is keeping a close watch over this situation and its developments, and the performance and results of the licensees' verifications in particular, in order to ascertain that there is no adverse impact on the safety of any equipment currently in service.