- 165 - 6 Severe accident management This chapter presents the organisational and material measures implemented by EDF to managing severe accidents (SA). Severe accidents are characterised by significant damage to the fuel in the reactor building or the fuel building. In order to fulfil the duties incumbent upon it in an emergency situation, the licensee must have a robust organisation, particularly for the extreme situations studied in the context of the Complementary Safety Assessments (CSAs). ASN will therefore instruct EDF to integrate in the hard core provisions (see § 8), the elements vital for emergency management, that is to say the emergency management rooms, the necessary material resources, the communication means and the technical and environmental instrumentation. ASN will also ask EDF to include in the hard core the operational dosimetry, measuring instruments for radiation protection, and the personal and collective protection equipment. The emergency management premises shall be designed to deal with hazards beyond the current baseline safety requirements. They shall be accessible and habitable during long-duration emergencies and be designed to accommodate the crews necessary for the long-term management of the site. The control rooms are also vital for emergency management, therefore it is important that their accessibility and habitability should permit the management and monitoring of all the site reactors if hazardous or radioactive substances are released. ASN will also prescribe the implementation of an emergency response system comprising specialised teams and equipment, capable of taking over from the personnel on a site affected by an accident and of deploying additional emergency response resources within 24 hours, with operations starting on the site within 12 hours from the time of call-out. The Fukushima accident proved that an external hazard could affect several facilities on a given site simultaneously. In the light of the CSAs, ASN considers that the EDF's current emergency organisation does not take sufficient account of this possibility. ASN with therefore ask EDF to supplement its emergency organisation so that it can manage a "multi-facility" event. On sites with several licensees, it is also important that they coordinate emergency management and limit the impact on the neighbouring facilities. An instruction will be issued in this respect, demanding the reinforcement of coordination between the licensees and operators of nuclear and non-nuclear facilities alike. Moreover, ASN considers that at present the means of limiting releases in the event of core meltdown are not sufficiently robust for the levels of risk considered in the CSA. In the same way as for the prevention measures, ASN will require EDF to define a series of measures to limit releases in the event of a severe accident resulting from risks of a higher level than those considered in the current baseline safety standard. EDF shall in particular propose improvements to the venting and filtration system in order to improve its robustness and its effectiveness. EDF shall continue with its studies into the prevention of the pollution of groundwater and surface waters in the event of a severe accident with core melt. Regarding the spent fuel pool, given the difficulty or even the impossibility of deploying effective means of mitigating the consequences of prolonged exposure of the fuel assemblies, ASN will require EDF to define and implement tightened measures to prevent the fuel assembly exposure. 6.1 Licensee's accident management organisation and measures 6.1.1 Licensee's accident management organisation In the CSA specifications ASN asked EDF to present its emergency organisation for managing accident situations, including the availability of competent personnel capable of intervening, shift management, measures taken to optimise personnel intervention (consideration of stress, psychological pressure, etc.), recourse in accident situations to outside technical support (and alternative solutions should this support become unavailable), as well as the procedures, training, and exercises.
RkJQdWJsaXNoZXIy NjQ0NzU=