France’s Nuclear Safety Authority (ASN) has launched an investigation into fraud affecting nuclear safety, after receiving 22 warnings from whistleblowers.

In November, ASN launched a website where the public can report irregularities following the discovery in 2016 of falsified manufacturing documents at former nuclear reactor maker Areva (now Framatome) and a series of problems with weldings and components French reactors.

ASN said it had launched an investigation into a small number of the warnings, which had the characteristics of potential fraud cases and had referred four to the criminal court. According to ASN, its initial investigations had revealed several problems, such as the use of inappropriate materials; certain activities, such as welding or non-destructive examination, carried out by people who did not have the necessary skills.