Since 2008, several inspections by ASN have examined the prestressing system of the Reactor Building containment. During construction of the first concreting lifts of the inner containment wall, EDF notified ASN of noncompliance issues relating to the prestressing system (see Information Notice No. 8).
In May 2011, new noncompliance issues regarding positioning of portions of the prestressing sheaths were identified. In addition to occasional deviations, ASN found that recurring anomalies in the system indicated a lack of preparation, skills and training in safety culture on the part of workers and shortcomings in EDF’s monitoring of its subcontractors. As a result, ASN requested EDF to suspend concreting of the inner containment wall on 23 June 2011 and to present an action plan to avoid any further deviations in constructing the prestressing sheaths.