EPR Reactor: Information Letter n°2: ASN asks EDF for tighter control on construction work

View taken on 25 October 2007 © AFP/MYCHELE DANIAU

During its inspection activities concerning the construction of the EPR, ASN has detected several anomalies in concrete structural work since the beginning of 2008.

On 21 May 2008, EDF informed ASN about an issue concerning the rebars in a part of the foundation raft of a building designed to house some of the reactor safeguard systems. This problem was reported after several others, the last of which, concerning rebars in the foundation raft of the future spent fuel storage building, was detected by ASN on 5 March 2008 during one of its routine site inspections.

ASN believes that while these recurrent anomalies have no negative impact on safety, they point to a lack of rigour from the operator regarding the supêrvision of construction operations, difficulties in monitoring the work of external service providers and organisational shortcomings.

Under current conditions, it considers that concrete pouring activities on the site do not guarantee a standard of quality control in compliance with the requirements of a nuclear facility.

For this reason, ASN asked EDF:

• first, to suspend concrete pouring operations on safety-related structures, as announced by Thomas Houdré, the Head of ASN's Caen Division, at the regional press conference held on 27 May 2008,
• secondly, to analyse the malfunctions observed and the corrective action required. More particularly, the Authority has asked EDF to tighten up not only the technical controls carried out by service providers working on the site, but also its own monitoring activities and discrepancy management procedures.

This suspension does not apply to concrete pouring work on non safety-class structures or on reinforcement operations, which continue.