ASN validates the inspection method adopted by Areva NC following an incident affecting a uranium hexafluoride transport packaging

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On 18^th December 2013, ASN was informed by Areva NC of the discovery of a lifting lug weld that had separated from a 48Y^[1] cylinder stored on the Pierrelatte site (Drôme département).

Following this discovery and the first checks performed on the 48Y cylinders, ASN on 17^th March 2014 asked all those in possession of such cylinders in France to carry out no shipments with these cylinders on the public highway when filled with uranium hexafluoride and to neither handle nor transport 48Y cylinders filled with liquid uranium hexafluoride within the nuclear sites, if these operations entail loading of the cylinder lifting lugs and unless the satisfactory strength of these lugs has been checked in accordance with criteria approved by ASN.

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Following this request, Areva NC proposed a method for inspecting the lifting lugs on the 48Y cylinders, based on:

• a visual and magnetic particle inspection of the lifting lug welds;
• a load test with 1.5 times the maximum working load on the two pairs of diametrically opposed lifting lugs;
• a second visual and magnetic particle inspection of the lifting lug welds.

If no defect is detected further to these checks, the cylinder lifting lugs are considered to be suitable for handling or stowage on and off the site. The cylinders for which one of the checks performed revealed a defect are removed from service pending the definition of repair methods.

ASN examined the procedure submitted by Areva NC and the results of the measurements in high acceleration and snatch lifting situations. Based on these results, ASN considered that the method proposed was suitable for handling conditions on the Tricastin site, where this type of cylinder is used. The 48Y cylinders inspected by this method can thus be transported on the Tricastin site and shipped on the public highway.

ASN also asked Areva NC to provide it with a summary of the tests carried out, every two months and to send it a document summarising the analysis of the incident of 18^th December 2013.