- 207 - emergency management centres, the material resources needed for emergency management, the means of communication and the essential technical and environmental instrumentation. ASN shall also ask EDF to include in this hard core the operational dosimetry resources, the measuring instruments required for radiation protection and individual and collective protection systems. The emergency management premises shall be designed for hazards beyond the current baseline safety requirements. They shall be accessible and habitable during long-duration emergencies and designed to accommodate the crews necessary for long-term site management. The control rooms are also areas that are essential in emergency management and it is therefore important that their accessibility and habitability allow operation and monitoring of all the reactors on a given site in the event of a release of dangerous or radioactive substances. ASN shall also require the implementation, before the end of 2013, of intervention measures comprising specialist crews and equipment, able to take over from the operating personnel on a damaged site in less than 24 hours, and to deploy additional emergency intervention resources in less than 24 hours, with operations beginning on the site within 12 hours from the time of call-out. The Fukushima accident proved that an off-site hazard could affect several facilities on the same site at the same time. Following the CSAs, ASN therefore considers that the current emergency organisation at EDF does not take sufficient account of this possibility. ASN will thus be asking EDF to complete its emergency response organisation so that it is able to manage a "multi-facility" event. For multi-licensee sites, it is also important that the licensees coordinate the management of an emergency and limit the impact on the neighbouring facilities. This point will be the subject of a requirement stipulating the reinforcement of coordination between the licensees of nuclear, but also non-nuclear facilities. ASN also considers that to date, the means of limiting releases in the event of a core melt are insufficiently robust to the hazard levels adopted in the CSAs. In the same way as for the preventive measures, ASN will be requiring that EDF define a range of measures able to limit the releases in the event of a severe accident involving hazards in excess of those adopted in the current baseline safety requirements. EDF will in particular propose improvements to the venting and filtration system to improve its robustness and its effectiveness. EDF will also complete its feasibility studies with a view to implementing technical measures such as a geotechnical containment or system with equivalent effect, designed to protect groundwater and surface waters in the event of a severe accident with core melt. More particularly with respect to the spent fuel storage pools, EDF examined the consequences of a natural hazard, assuming that the integrity of the pools equipment remains undamaged. In these situations, EDF concludes that with regard to the residual heat removal from the fuel, long-term topping-up of the water in the pool must be guaranteed, in order to compensate for the boiling induced by the loss of cooling. This will be the subject of an ASN requirement. In the review of the CSA reports by IRSN, the risk of leakage from the equipment, such as to compromise the water inventory in the pools in the reactor building and the pools for spent fuel storage, was also considered. These situations can lead to a cliff-edge effect, particularly owing to the significant drop in the water inventory present, the resulting reduction in the time before dewatering of the fuel and the particular constraints of operational management of these accidents. In this respect, given the difficulty, or even the impossibility of implementing effective measures to limit the consequences of prolonged dewatering of the fuel assemblies, ASN will require that EDF define and implement reinforced measures to prevent dewatering of these assemblies. Organisational and human factors and subcontracting ASN considers that additional measures must be taken regarding emergency management and the training of the personnel involved. It will require that the licensees define the human interventions required for management of the extreme situations studied in the complementary safety assessments and take account of emergency crew shift changes and the required intervention logistics.
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