ASN Report 2020

change in organisation in the Orano group BNIs undergoing decommissioning, liable to compromise the principle set out in the Environment Code, whereby operational responsibility for a BNI lies with its nuclear licensee. Orano thus submitted a request for a waiver to this principle in December 2020 and ASN will issue a position statement on it in 2021. 2.2  Lessons learned from the Fukushima Daiichi accident Priority was given to integrating the lessons learned from the Fukushima Daiichi Nuclear Power Plant (NPP) accident (in Japan) on all the fuel cycle facilities. The licensees supplied stress test reports in September 2011 for all facilities and sites, with the exception of BNI 63 in Romans-sur-Isère, for which the report was submitted in September 2012. In June 2012, ASN set additional requirements for the Orano and Framatome facilities assessed in 2011, in the light of the conclusions of the stress tests. These requirements more specific­ ally stipulate the deployment of a “hardened safety core” of material and organisational provisions designed to prevent a severe accident or limit its spread, mitigate large-scale releases and enable the licensee to fulfil its emergency management duties. Generally speaking, Orano and Framatome designed and implemented new means to deal with extreme situations in their facilities in good time. More specifically, the Local Emergency Command Posts (PCD‑L) on the Romans-sur-Isère and Tricastin sites were relocated to new emergency management buildings designed to withstand extreme hazards. These buildings more specifically contain a ventilation system with filtration enabling the personnel present to be protected against a toxic release from the site’s facilities, neighbouring facilities or, on the Tricastin site, a radioactive release from the neighbouring NPP. With regard to the La Hague site, Orano carried out work and deployed means to ensure significant water reserves in the event of an extreme situation, and means to ensure recirculation of water under the storage pools and thus maintain a minimum water level above the fuel assemblies in the event of a leak. Finally, the site’s new PCD-L emergency building, which is robust to extreme hazards, has been operational since 2019. On the Marcoule site, Orano has begun the construction of its new emergency building, designed to withstand extreme hazards. This construction site is however considerably behind schedule owing to recurring difficulties between the licensee and its civil engineering contractor and it might not be completed before the end of 2021. ASN nonetheless considers that the progress of the post- Fukushima work and the organisational measures adopted are satisfactory at Orano and Framatome. 2.3  Periodic safety reviews of fuel cycle facilities Since the publication of the Decree of 2 November 2007, all the BNI licensees must carry out periodic safety reviews of their facilities at least every ten years. These exercises were carried out gradually on the fuel cycle facilities. The first reviews concerned BNIs 151 (Melox) and 138 (Socatri) and identified numerous points on which these facilities could be reinforced. Most of this work has today been completed. The examination of these periodic safety reviews confirmed that the subjects to be examined by the licensee during the periodic safety reviews, along with the required methodologies, should be defined during what is referred to as the orientation phase. In addition, probabilistic analyses must be added to the safety cases for all the BNIs. Following the periodic safety review of plant UP2-800 (BNI 117), Orano established an ambitious safety analysis methodology based on methods applied to Installations Classified for Protection of the Environment and presented it to ASN in 2020 with a view to extending it to all of its BNIs. Its implementation for the forthcoming periodic safety review of BNI 116 will represent significant progress for analysis of the complex accident sequences to be examined by ASN. The periodic safety review of BNI 98 (FBFC) comprises safety improvements to the facility, notably with regard to controlling fire risks, controlling criticality and reinforced civil engineering. However, it demonstrated the need for improved incorporation of the hazards linked to dangerous substances into the safety case of the fuel cycle facilities, while ensuring a level of stringency at least equivalent to that of Seveso classified upper-tier facilities. In 2020, ASN therefore issued a binding requirement in its resolution associated with this periodic safety review, for updating of the safety case with regard to the risks resulting from dangerous substances. The periodic safety reviews show the importance of an in situ verification of the conformity of the Protection Important Componant (PIC) that is as exhaustive as possible, or as represent­ ative as possible of the PIC that are not accessible. They also illustrate the need for a robust approach to the control of the ageing of fuel cycle facilities. It may be complex to develop these approaches because most of the fuel cycle facilities are unique. In the context of the faster-than-anticipated corrosion of the fission products evaporators-concentrators and other equipment in the La Hague plant, the management of ageing is a priority issue for ASN with regard to the cycle back-end facilities, which are the subject of dedicated inspections and increased vigilance in the examination of the ongoing periodic safety reviews. 2.4  Particular regulatory actions conducted in consultation with the Defence Nuclear Safety Authority The upcoming declassification of the Tricastin DBNI to a BNI will mean that ASN will take over responsibility for oversight of a part of the facilities it contains. Together with the Defence Nuclear Safety Authority (ASND), ASN ensures that consistency is maintained in the application of the safety and radiation protection requirements for the facilities under their respective responsibility on the Tricastin site. Most of the facilities regulated by the ASND have in fact been shut down or are being decommissioned and no longer play a role in national defence. They should therefore no longer be subject to secrecy measures and will thus be gradually declassified to BNI status in the coming years. ASN and ASND have set up a working group to clarify the steps of ASN’s takeover of the regulation of the safety of activities on this site. The decision was made that this takeover will be gradual and will be an opportunity to reorganise the oversight of the Tricastin site, so that the whole site, including soils contaminated by legacy pollution, are under the control of one or other of the safety regulators. In 2020, ASN informed the Minister in charge of nuclear safety of its opinion on Orano’s proposal to reorganise the platform following declassification of the DBNI. Depending on their purpose, the various DBNI facilities should be grouped within existing or new BNIs. Their safety baseline requirements will then need to be brought into line with the BNI System. 328 ASN Report on the state of nuclear safety and radiation protection in France in 2020 11 – “NUCLEAR FUEL CYCLE” INSTALLATIONS