- 23 - 2.1.12 Site isolation in the event of flooding The characteristics of site isolation in the event of flooding are known and described in the safety report. They depend on numerous parameters (elevation of roads, vulnerability of the environment, etc.) and differ from site to site (7 days for Belleville, 3 days for Nogent, 12 hours for Gravelines, 2 days for Tricastin). For the sites impacted by the risk of isolation, procedures to deal with this situation are defined (Nogent, Saint-Alban), in particular in the PUI. It should be pointed out that the new 2011 flood RPC for Tricastin states that this site is now exposed to isolation, requiring that the site review its entire strategy in this area. Similarly, at Cruas, the new procedures have extended the isolation period from 2 days to 12 days, yet no steps have been taken on the site to deal with this extension. Certain flood situations are foreseeable (Blayais, Belleville) or would develop slowly (Fessenheim) making it possible to anticipate organisation of the alert. Some sites have also signed agreements with the Government departments concerned, such as the SDIS (Belleville, Blayais). ASN considers that overall, site isolation management is satisfactory, except for Tricastin and Cruas which will rapidly need to include the risk of isolation in their operating procedures and organisational arrangements. Several sites have limited the risk of isolation by building heliports (Cattenom, Chooz, Nogent, Tricastin and 2 at Belleville) or plan to build them in the coming years (Fessenheim in 2015). Saint-Alban plans to modify the access roads to prevent them from becoming flooded and a helicopter landing exercise was held. The provisions in terms of the resources (human, material, supplies, etc.) in the event of flooding in order to guarantee the living conditions of the staff blocked on the site are generally those of the PUI (Cattenom, Fessenheim) or the RPC (Blayais). Some sites have taken steps in case it is necessary for the personnel to stay on the site (Fessenheim). Certain sites, not subject to flooding (Nogent for example), nonetheless have 90 inflatable mattresses and inflators as part of the PUI arrangements, enabling a 60strong duty crew to sleep on-site, along with survival rations for 24 hours permanently stored in the warehouse. ASN finds that EDF has made adequate provision for isolation of the sites in its definition of the resources deployed in the event of site isolation. 2.1.13 Flooding of galleries between units and management On certain sites (Chooz, Nogent, Paluel) the turbine hall galleries between units cannot be sealed, potentially leading to flooding of the turbine hall (as happened at Nogent in 2006), which could require multi-unit management. Nonetheless, this appears to be defined in most of the operating procedures (Blayais, Cattenom, Chooz, Fessenheim). ASN finds that EDF has taken satisfactory account of the possibility of flooding of the galleries between units in its operating procedures. 2.1.14 Diversity of telecommunication resources The telecommunication resources would appear to be diversified and the internal connection cables are designed to withstand flooding. The sites inspected have at least one satellite phone. ASN finds this organisation and its implementation to be satisfactory. 2.1.15 Optimisation of discharges at the prediction of a flooding risk When there is a predicted flooding risk, most of the operating procedures define what steps are to be taken (drainage of tanks for instance). The inspectors did however observe that the Chooz site failed to take this into account, considering that the know-how of the staff was sufficient. ASN finds that the steps to be taken when a flood risk is announced must be clearly indicated. 2.1.16 Exercises: deployment of flood protection and prevention equipment (cofferdams, sandbags, mobile pumping resources) The inspectors asked whether mobile pumping resource deployment exercises were held. This is the case on most sites, but the exercises are often incomplete and do not include a real operating test (Blayais, Belleville, Tricastin) or are held too infrequently (last exercise in 2008 at Saint-Alban and in 2004 at
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