ASN Report 2022

With regard to environmental protection, ASN wants to see improvements in the site’s practices. Although waste management remains satisfactory on the whole, the analysis of significant environmental events – including the groundwater pollution by effluents containing tritium in December 2021 and the exceeding of the maximum regulatory concentration of hydrocarbons at the outlet of an oil remover in October 2022 – has shown that the control of effluent storage areas and liquid containment, and the maintenance of the associated monitoring devices, need to be improved. As far as occupational safety is concerned, ASN considers that the site’s results are satisfactory and stable with respect to the preceding year. The accident rate, particularly during the reactor outages, was kept down. ASN nevertheless notes that a serious accident occurred this year during work on a ventilation system motor. THE “NUCLEAR FUEL CYCLE” FACILITIES The Tricastin “fuel cycle” installations mainly cover the upstream activities of the “fuel cycle” and, as of the end of 2018, they are operated by a single licensee, Orano Cycle, which became Orano Chimie-Enrichissement on 1 January 2021 and is called “Orano” hereinafter. The site comprises: • the TU5 facility (BNI 155) for converting uranyl nitrate UO2(NO3)2 resulting from the reprocessing of spent fuels into triuranium octoxide (U3O8); • the W plant (ICPE within the perimeter of BNI 155) for converting depleted uranium hexafluoride (UF6) into U3O8; • the former Comurhex facility (BNI 105) and the Philippe Coste plant (ICPE within the perimeter of BNI 105) for converting uranium tetrafluoride (UF4) into UF6; • the former Georges Besse I plant (BNI 93) for the enrichment of UF6 by gaseous diffusion; • the Georges Besse II plant (BNI 168) for centrifuge enrichment of UF6; • the uranium storage areas at Tricastin (BNI 178, 179 and 180) for storing uranium in the form of oxides or UF6; • the maintenance, liquid effluent treatment and waste packaging facilities (IARU – BNI 138); • the Atlas process samples analysis and environmental monitoring laboratory (BNI 176); • a Defence Basic Nuclear Installation (DBNI), which more specifically accommodates former facilities undergoing decommissioning, radioactive substance storage areas and a liquid effluent treatment unit. Following the inspections it conducted in 2022, ASN considers that the level of safety of the Orano facilities on the Tricastin site is satisfactory. In 2022, Orano improved its organisation for analysing the conformity of the facilities with the regulations and further improved its follow-up of the commitments made to ASN. Trident, the new waste processing facility in BNI 138, continued its gradual start-up. Construction of the new Uranium Reprocessing Storage Facility called “FLEUR” (BNI 180) was completed and its commissioning has been authorised by ASN resolution 2023-DC-0750 of 3 January 2023. Lastly, ASN continued examination of the Creation Authorisation Application (DAC) for the future containers maintenance unit (AMC2). This DAC was the subject of a public inquiry from 10 December 2021 to 12 January 2022. The AMC2 unit will take over from the existing unit (AMC) which should stop operating in 2024. Orano did not start the construction work at the end of the public inquiry because of contractual problems, which will delay commissioning of the AMC2 unit. In 2022, ASN conducted a campaign of simultaneous unannounced inspections on BNIs 93, 105, 138, 155, 168, 178 and 179, focusing on the management of the facilities in normal operating situations with the aim of checking Orano’s organisation in this area. During these inspections the inspectors observed changes of shift, operators at work in the control room and during patrols and lockout/tagout operations. The overall result of these inspections is satisfactory. To check the progress of treating the backlog of diverse radioactive substances stored on the site, ASN asked Orano to present an annual statement on the progress of its action plan for the treatment of these substances. Some operations planned with Russia have been suspended and alternatives must be found. Lastly, in 2022, to increase its enrichment capacities, Orano initiated the project to extend the Georges Besse II North enrichment plant, which will undergo public consultations as of 2023. In 2023, ASN will also ensure that Orano has and engages all the necessary resources in the new construction projects, whether to increase its production capacity or to improve certain support functions such as the AMC2 project or treating the backlog of radioactive substances stored on the site. Orano uranium chemistry plants TU5 and W BNI 155, called “TU5”, can handle up to 2,000 tonnes of uranium per year, which enables all the UO2(NO3)2 from the Orano plant in La Hague to be processed for conversion into U3O8 (a stable solid compound that can guarantee storage of the uranium under safer conditions than in liquid or gaseous form). Once converted, the reprocessed uranium is placed in storage on the Tricastin site. The W plant situated within the perimeter of BNI 155 can process the depleted UF6 from the Georges Besse II plant, to stabilise it as U3O8. ASN considers that the facilities situated within the perimeter of BNI 155 are operated with a satisfactory level of safety. Although 2022 was marked by a significant drop in the number of significant or notable events, ASN was attentive to the lessons learned from the two contamination events in the drumming enclosure of the TU5 plant. In 2023, ASN will be attentive to the maintaining of due operating rigour and will examine the impacts that the project to increase the capacity of the Georges Besse II North plant has on the W plant. 42 ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2022 Regional overview of nuclear safety and radiation protection • AUVERGNE‑RHÔNE‑ALPES •