Complementary-safety-assessments-french-nuclear-safety

- 346 - In the particular case of the Jules Horowitz reactor (JHR), it should be noted that margins are already designed into this facility in compliance with the most recent requirements. However, its current situation - under construction – led the licensee to propose additional improvements. For the other facilities, ASN will submit requests to CEA regarding the few nonconformities or missing design studies that need to be addressed. The flooding risks are minor for the CEA facilities examined in 2011. However, given the particular vulnerability linked to the presence of large quantities of sodium, ASN will be asking that additional studies be conducted on this risk and that improvements be made to the Phénix facility. Improving risk management For the ATPu facility and the Masurca reactor fissile materials store, the main risk concerns the possible dissemination of materials in the event of destruction of the buildings. The risk of criticality or fire could also make crisis management more difficult. Given the current state of the facilities, ASN will be asking the licensee:  concerning ATPu, to provide an operational estimate of the quantities of radioactive material present per area and to take the necessary steps to ensure that this estimate is available at all times, to allow effective management in an accident situation;  for Masurca, to relocate the fissile material as rapidly as possible to a facility designed in compliance with seismic standards, at a time to be set in an ASN requirement. CEA has already made a previous commitment to ASN to carry out this relocation no later than at the end of 2013. For the reactors (Jules Horowitz, Phénix and Osiris), the main risk is the loss of cooling. However, a considerable time would elapse before the occurrence of any cliff-edge effects. ASN will be asking that the improvements identified for the RJH be implemented, in order to reinforce the ultimate backup cooling in the event of the most extreme situations involving multiple loss of redundant equipment. Finally, ASN will be asking that additional steps be taken so that, in all circumstances, essential technical and environmental data be transmitted to a centre allowing management of the accident situation. Research facility operated by ILL Reinforcing the robustness of the facilities to the earthquake and flooding risk Seismic behaviour nonconformities were identified. Most are the result of delays in processing the follow-up to the last periodic safety review. ASN will be asking for conformity work to be initiated in the very short term; some steps are already in progress. The flooding risk was examined conservatively by the licensee; it would be a major risk in the event of multiple dam bursts on the Drac, especially with regard to crisis management, given the loss of several means of information and intervention. The licensee proposed building a new crisis PC, with information and intervention resources, designed in compliance with seismic standards and protected from flooding, even in an extreme situation. In the meantime, ASN will be asking for interim improvements to be put into place. Improving risk management With regard to the loss of cooling, it would appear that a considerable time would elapse before the occurrence of any cliff-edge effects, except in the event of significant breaches following an earthquake. The main risks are linked to the effect on the facility of extreme off-site hazards (flooding, earthquake). ASN will be asking for the planned improvements to be implemented in the near future, as proposed by the licensee, in particular concerning the resources for managing an accident situation. Additional measures will in particular need to be taken so that in all circumstances, essential technical and environmental data can be transmitted to a centre allowing management of the accident situation.

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