- 321 - premises could be effective insofar as the chemical or radiological environment will not permit on-site intervention with the extinguishing powder. Consequently, the CEA envisages firstly providing a rapidly deployable nitrogen tank, and secondly creating a dedicated access to the rooms so that the extinguishing powder can be introduced via a dry riser-type connection. It does not envisage additional means in the event of a concomitant leak of the double-walled main vessel and the primary containment, considering that the earthquake robustness of the primary containment vessel is amply sufficient (estimated safety factor of 25). The CEA also proposes parking the two FLS fire-fighting trucks (one filled with Marcalina powder) in a place that will not be impacted by the possible effects of an earthquake. In the event of a sodium-water reaction, the licensee plans venting the hydrogen produced. Nevertheless, if a large-scale sodium-water reaction takes place, the intervention possibilities will be very limited, and perhaps inexistent. In an earthquake occurs, only sodium leaks in the double-walled vessel and the fuel storage tank vessel can be detected by the SAMU (Ultimate Situation Measurement Acquisition System) which has an autonomy of 8 hours and can be resupplied by a diesel generator set. It should be noted that the CEA has undertaken to detail its action plan relative to additional sodium fire extinguishing means as envisaged in the ECS report. In the event of flooding, a sodium-water reaction could be detected with the portable hydrogen detection instruments of the FLS. Identification of the factors potentially hindering accident management and of the resulting constraints In its CSA report the CEA analyse the possible consequences of an earthquake or flood on the availability of the emergency intervention means, and notably: total loss of electrical power supplies and fluid supplies; a secondary accident due to a fire, explosion or a criticality accident; damage to the access road to the centre; potential contamination of water in the event of flooding; atmospheric contamination; the presence of propane in the northern area of the centre; the presence of hydrogen in the NPP; the presence of corrosive water (sodium hydroxide) in and near the NPP; uncertainty of the availability of the technical intervention means owing to their potential damage further to the earthquake. The licensee has given a commitment regarding the assessment of the induced hazards external and internal to the facility (global CEA commitment). Conclusion on the planned organisational measures for accident management The CEA indicates in its CSA report that the availability and functionality of the technical and human resources necessary for the intervention might not be fully guaranteed after an earthquake of exceptional intensity: the implementation of emergency management such as it is planned for in the PUI risks being disrupted by shortcomings in equipment and personnel availability. The CEA nevertheless underlines the ongoing construction of a building designed to seismic standards, situated outside the floodable zone, and accommodating the emergency command post in particular. Moreover, the CEA indicates in the CSA dedicated to the Phénix facility that further measures are planned to improve the situation, such as having vehicles stationed in appropriate places out of range of the impacts of an earthquake: a vehicle equipped with portable radiation protection equipment, two FLS fire-fighting vehicles, pumping gear and a diesel generator set. A satellite telephone will also be provided in the centre's FLS security command post.
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