Irregularities detected in Areva’s Creusot Forge plant: ASN interim briefing

Since 18^th May, when EDF transmitted its analyses of the irregularities brought to light in the Creusot Forge plant, ASN has been conducting its own technical review on the basis of the data transmitted and the additional evidence it requested. As a priority, ASN is dealing with the cases liable to have the most significant implications for reactor safety. In any case, prior to each reactor restart, it ensures that the irregularities detected do not compromise safety.

On 15^th June, EDF informed ASN that it had completed the characterisation of 79 of the 80 irregularities currently identified in the manufacturing files of the Areva Creusot Forge plant as affecting its reactors in service. EDF concludes that these irregularities have no consequences for the safety of the reactors concerned.

The irregularity still undergoing characterisation concerns a steam generator in Fessenheim NPP reactor 2. In order to carry out additional investigations, EDF shut down this reactor on 13^th June and submitted an initial analysis to ASN on 15^th June.

The 80 irregularities concern the steam generators, vessels or main primary system piping on the following reactors:

• Le Blayais NPP, reactors 1 and 3;
• Bugey NPP, reactors 2, 3 and 4;
• Cattenom NPP, reactor 1;
• Chinon NPP, reactors 1 and 3;
• Civaux NPP, reactor 2;
• Dampierre NPP, reactors 1, 3 and 4;
• Fessenheim NPP, reactors 1 and 2;
• Golfech NPP, reactor 2;
• Gravelines NPP, reactor 3;
• Paluel NPP, reactor 1;
• Saint-Laurent-des-Eaux NPP, reactors 1 and 2;
• Tricastin NPP, reactors 2 and 3.

These extremely varied irregularities comprise inconsistencies, modifications or omissions in the production files, concerning manufacturing parameters or test results. Some information concerning forging, heat treatment, mechanical testing or chemical analyses were thus not sent to the Creusot Forge customer or to ASN. Nineteen of these irregularities concern compliance with the customer’s specifications and the manufacturing rules for nuclear pressure equipment¹.

Areva informed ASN that irregularities had also been identified on components manufactured for the EPR reactor currently under construction in Flamanville. At this stage, ASN has no information on their nature or their consequences.

With regard to the components intended for other countries, Areva has informed the customers concerned.

Investigations are continuing and could well bring further irregularities to light. ASN is ensuring that the review process will be seen through to completion, more specifically through inspections, in order to assess all the anomalies which may have affected past manufacturing operations and draw any relevant conclusions regarding the safety of the facilities.