ASN Report 2020

More generally, the licensee must maintain its efforts to increase its operating rigour, particularly through the detection and effective management of deviations. Orano uranium fluorination plants Pursuant to the ASN requirement, the oldest fluorination facilities were shut down def initively in December 2017. The shut down facilities have since been emptied of the majority of their hazardous substances and are now in the decommissioning preparation phase. The decommissioning of BNI 105 is now authorised by Decree 2019-1368 of 16 December 2019. The main issues associated with decommissioning concern the risks of dissemination of radioactive substances, of exposure to ionising radiation and of criticality, on account of the residual uranium-bearing substances present in some items of equipment. ASN expects the licensee to make the necessary efforts to repackage the packages containing radioactive and hazardous substances stored on areas 61 and 79 within the set deadlines. ASN also inspected the upgrading of the process core of the Philippe Coste plant, whose facilities are classified Seveso high threshold and replace those of BNI 105 (formerly Comurhex). The main units of this plant were commissioned in 2019 and revealed design defects. The second fluorine production unit underwent tests with a view to gradual commissioning until the end of 2020. For the Philippe Coste plant the year 2020 was thus marked by a “major shutdown” during which, among other things, all the crystallisers were replaced further to design defects which had led to degraded operating conditions for several months and to compensatory measures. ASN notes that the licensee conducted the analysis and resolved these technical difficulties efficiently. ASN verified that the process core had been properly upgraded but nevertheless detected a lack of supervision and monitoring of the crystalliser replacement work. Commissioning of the Philippe Coste plant’s unit 68 for treating non-uranium-bearing effluents has again been postponed until 2021, on account of an inappropriate initial design. Lastly, ASN notes that the year 2020 was marked by high production expectations of the Philippe Coste plant in a context where the licensee had to cope with difficulties due to the defects in its new facilities and the design obsolescence of the old facilities still in service. Through its oversight actions ASN observed that this context led to a reduction in the control of risks in the management of nonconformities and technical problems. This context also led to the reporting of numerous events significant for the environment. In 2021, ASN will be attentive f irstly to the conditions of commissioning of the new fluorine production unit and the effluent treatment unit of the Philippe Coste plant, and secondly to the repackaging and processing of the uranium- bearing materials present in BNI 105 in preparation for its decommissioning. Georges Besse I enrichment plant The Georges Besse I (Eurodif) uranium enrichment facility (BNI 93) consisted essentially of a plant for separating uranium isotopes by the gaseous diffusion process. After stopping production at this plant in May 2012, the licensee carried out, from 2013 to 2016, the Eurodif “Prisme” process of “intensive rinsing followed by venting”, which consisted in performing repeated rinsing of the gaseous diffusion circuits with chlorine trifluoride (ClF 3 ), a toxic and dangerous substance. These operations, which are now completed, allowed the extraction of virtually all the residual uranium deposited in the diffusion barriers. The licensee submitted its application for final shutdown and decommissioning of the facility in March 2015. Examination of the file continued in 2019 and the decree instructing Orano to proceed with the decommissioning of the Georges Besse I plant was published on 5 February 2020. The decommissioning issues particularly concern the large volume of very low level waste (VLLW) produced, including 160,000 tonnes of metal waste. In 2020, ASNmonitored firstly the licensee’s preliminary studies and operations to determine the procedures for cutting up the components, and secondly the supervision of the effluent transfers and the materials still to be removed. In 2020, ASN checked the effective operation of the facility for hydraulic containment and treatment of the alluvial water table polluted with perchloroethylene and trichloroethylene and considers the results satisfactory. The main residual risk of BNI 93 is now associated with the UF 6 containers in the storage yards, which are still attached to the perimeter of the facility. These yards should ultimately be attached to the Tricastin uranium storage yards (BNI 178). Georges Besse II enrichment plant The Georges Besse II plant, BNI 168, became the site’s new enrichment facility following the shutdown of Eurodif. It uses the centrifuge process to separate uranium isotopes. The standard of safety of the plant’s facilities in 2020 was satisfactory. The technologies utilised in the facility enable high standards of safety, radiation protection and environmental protection to be reached. ASN considers that the licensee ASN has noted that the Covid‑19 pandemic has not disrupted the normal operation of the plants in service. The licensee managed to maintain safety and radiation protection both in the production units and on the BNI construction or modification worksites. During the first lockdown of the pandemic, all the facility decommissioning worksites were stopped, resulting in the year’s targets falling behind schedule. THE IMPACT OF COVID-19 ASN Report on the state of nuclear safety and radiation protection in France in 2020 45 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION AUVERGNE-RHÔNE-ALPES