EDF has stated that it wishes to build a new electricity generating unit using a third-generation nuclear reactor, the EPR, on the Flamanville site (Manche).

In accordance with the Environment Code, EDF referred the issue to the National Public Debates Committee (CNDP) on 4 November 2004. The CNDP decided to hold a national public debate on the EPR project and handed the matter over to a Special Public Debates Committee (CPDP). The aim is to ensure that all the stakeholders concerned (owner, public authorities, elected officials, associations, experts, local residents, general public, etc.) are informed and can express themselves as extensively as possible during the project preparation phase.

The four-month long debate is being held both locally where project construction is planned, and nationally. The ASN is involved in the public meetings held to deal with the various topics. At the end of this debate, EDF will take a decision on whether or not to build an EPR reactor in Flamanville.

• worker radiation protection;
• the corium recovery system (core-catcher);
• dealing with heatwave situations;
• design of the rod cluster control mechanisms;
• assumption discounting the possibility of a primary and secondary pipe break;
• steam generator design.

With regard to worker radiation protection, in 2004 the ASN considered that the target was not ambitious enough. The new dossier presented this year by EDF demonstrated a real effort to optimise the work sites which make a significant contribution to the collective dose. This now means that EDF can aim for a collective dose that is significantly lower than the lowest value obtained by the French nuclear power plants in service. At this stage in the design, this point is considered to be satisfactory by the ASN.

With regard to the core-catcher, the ASN considers that the design modifications and additional technical justifications presented are such as to demonstrate correct operation of the system. At this stage in the design, this point is considered to be satisfactory by the ASN.

Concerning heatwave situations, the ASN considers that the design measures for dealing with extreme climatic situations and which take account of the expected climate change over a time-frame of a century, are satisfactory. However, given the uncertainties surrounding this subject in the light of current knowledge, the ASN asked that in addition to the design measures adopted, facilities for in-service adaptation also be designed-in, should actual climate change prove to be greater than originally anticipated.

The planned rod control cluster mechanisms for the EPR reactor are appreciably different from those used in the existing EDF reactors, but similar to those fitted to the German Konvoi type reactors. The manufacturer plans to assemble two stainless steels of different grades to produce the mechanism's envelope structure. The ASN expressed reserves regarding the manufacturer's choice of these materials and the number of welds needed to make each envelope structure.

With regard to the primary and secondary piping, the EPR reactor designer envisages ruling out the possibility of pipe break in the safety demonstrations. The ASN reviewed the demonstration of this "break preclusion" concept, considering that it constituted the first level of a "defence in depth" type approach. On the basis of the SPN’s recommendation, it clarified the technical design, manufacture and operational requirements which would confirm the highly improbable nature of a pipe break.

The design choices for the steam generators were evaluated in the light of the new nuclear pressure vessel regulations (see point 3.1 below and chapter 3 point 2.2.1). The design of the EPR reactor steam generators benefits from the experience acquired with the N4 type reactor, the design of which had already taken account of the damage observed on the 900 and 1300 MWe series steam generators. However, the ASN considers that the data presented at this stage cannot confirm that the geometrical characteristics chosen actually meet the requirements of the new regulations.

The Flamanville nuclear site was chosen by EDF at the end of 2004 for siting of the EPR reactor if it were to be licensed. The ASN is preparing to review the studies concerning specific aspects of the chosen site (seismic activity, flooding risk, design of the pumping station, etc.).