- 206 - for the Tricastin, Fessenheim and Bugey sites, provides a study analysing the level of seismic robustness of the embankments and other structures designed to protect the installations against flooding and to present the consequences of a failure of these structures. Flooding Analysis of the CSAs demonstrated that the requirements resulting from the complete reassessment of the consideration of this risk on the nuclear power plants, completed in 2007, give the installations a high level of protection against the risk of flooding. However, ASN observes that the steps such as to meet these requirements have not yet all been taken. In order to ensure that this high level of protection is actually reached, ASN will require that EDF: completes the NPP protective measures within the time allotted following the "flood" reassessment of 2007, and no later than 2014; improves its management of volumetric protection of the installations. The ASN inspections brought to light the fact that the management of volumetric protection needs to be improved on several of the inspected sites; completes the heat sink design review, in particular with regard to prevention of the risk of clogging, initiated subsequent to the Cruas incident in 2009; strengthens the protection of the facilities against the risk of flooding in excess of the current baseline safety requirements, for example by raising the level of the volumetric protection. The CSAs highlighted the existence of cliff-edge effects (loss of electrical power supplies) for levels close to those used in the baseline safety requirements. Hazards resulting from the industrial environment The risk of a threat to an NPP as a result of accidents induced by off-site hazards on nearby industrial facilities or communication axes, was examined in the frame of CSAs. The EDF analyses are based on the data in its possession, because it has no information on the robustness of the off-site industrial facilities to an earthquake or to flooding. ASN will require that EDF completes this analysis, specifying the effects on its facilities of hazardous phenomena liable to occur on the facilities at risk situated in the vicinity of the site, including the extreme situations studied on the occasion of the CSAs. ASN will examine this analysis together with the services of the ministry responsible for the prevention of industrial risks. Loss of electrical power supplies and loss of cooling systems Analysis of EDF's CSAs reports showed that certain loss of heat sink and loss of electrical power scenarios could lead to core melt within a few hours, in the most unfavourable situations. ASN therefore considers that the robustness of the facilities needs to be increased by a certain number of means enabling them to deal with long-duration loss of electrical power sources or heat sink situations, capable of affecting all the facilities on a site. ASN will require that EDF implements strengthened measures, integrated into the hard core mentioned earlier, comprising a diesel generator and an emergency water supply able to withstand large-scale on-site and off-site hazards beyond the current basic safety requirements, able of dealing with a total loss of electrical power supply or cooling systems, such as to prevent core melt in these situations. Pending the progressive deployment of these measures, which will take several years, ASN will require the implementation of interim measures as of 2012, such as mobile electricity generating sets. Management of severe accidents To ensure that its duties in an emergency situation can be carried out, the licensee shall have a robust organisation, in particular in the extreme situations studied on the occasion of the CSAs. ASN shall therefore require that EDF include in the hard core the elements essential for emergency management, in other words the
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