ASN Report 2022

Given the old design of this facility by comparison with the best available techniques for protection against external hazards and for containment of materials in the event of an accident, the Osiris reactor was shut down at the end of 2015. The Isis reactor was definitively shut down in March 2019. Following submission of the decommissioning file for the entire facility in October 2018, ASN requested and received additional information giving more details on the operations planned at each stage of decommissioning and substantiating more precisely the initial state envisaged at the start of decommissioning and the results of the impact assessment. In late 2021, the CEA announced a radical change in the decommissioning strategy of BNI 40 with the postponement of commissioning of the equipment for treating and packaging irradiating waste. For the purpose of its examination, ASN is waiting for information on the new decommissioning scenario, particularly regarding the management of irradiating waste. Since the shutdown of the Osiris and Isis reactors and pending decommissioning of the facility, the removal of radioactive and hazardous materials and the decommissioning preparation operations are underway, with an organisation adapted to the new state of the facility. More specifically, the last of the irradiated fuel stored in the facility was removed in the second half of 2021. The inspections revealed a robust organisation for conducting the safety review and supervising the associated action plan. Improvements are nevertheless expected in the examination of compliance with regulations and the technical baseline requirements of the facility. The subject of static and dynamic containment is properly understood. The state of conservation of a ventilation duct however, requires particular vigilance. With regard to the prevention of pollution and detrimental effects, the updating of the hazardous substances inventory must be improved and further information on the facility’s water consumption is awaited. The tracking of commitments made to ASN and of deviations is satisfactory. Two significant events reported in 2022 are linked to problems of equipment aging, an important issue for the facility given the forecast time frames of the decommissioning operations. The licensee’s control of the decommissioning preparation operations, the management of waste and the monitoring of aging of the facilities shall be among the themes to which ASN will be attentive in 2023. Orphée reactor The Orphée reactor (BNI 101), a neutron source reactor, was a pool-type research reactor with a licensed power of 14 MWth. The highly compact core is located in a tank of heavy water acting as moderator. Creation of the reactor was authorised by the Decree of 8 March 1978 and its first divergence took place in 1980. It was used for conducting experiments in areas such as physics, biology and physical chemistry. The reactor allowed the introduction of samples to be irradiated for the production of radionuclides or special materials, and to perform non-destructive tests on certain components. The Orphée reactor, which was definitively shut down at the end of 2019, is now in the decommissioning preparation phase. The licensee submitted its decommissioning file in March 2020. The last irradiated fuel from the Orphée reactor was removed in 2020, greatly reducing the risks the facility represents. The continuation of the decommissioning preparation operations and the facility decommissioning scenario are currently being discussed following the CEA’s re-prioritising of the decommissioning operations and its consequences on the updating of the decommissioning strategy of BNI 101. Based on the facility inspections and monitoring carried out in 2022, ASN considers that the level of safety of the Orphée reactor is on the whole satisfactory. However, a number of points requiring special attention, such as identification of the safety important activities and their technical monitoring, and the formalising and tracking of the qualification files of safety important components, are necessary. The significant events show that vigilance is required in the monitoring of the periodic inspections and tests and of the effectiveness of the high efficiency particulate air filters. Improvements are expected regarding compliance with the storage rules for certain potentially activated materials or VLL packages. Following reactor shutdown, the decommissioning preparation phase is subject to particular scrutiny by ASN, notably the adaptation of the organisation and the personnel skills to manage new activities while maintaining the level of safety of the facility and keeping the activity schedules on track. Spent fuel testing laboratory The Spent Fuel Testing Laboratory (LECI) was built and commissioned in November 1959. It was declared a BNI on 8 January 1968 by the CEA. An extension was authorised in 2000. The LECI (BNI 50) constitutes an expert assessment aid for the nuclear licensees. Its role is to study the properties of materials used in the nuclear sector, whether irradiated or not. From the safety aspect, this facility must meet the same requirements as the nuclear installations of the “fuel cycle”, but the safety approach is proportional to the risks and drawbacks it presents. Further to the last periodic safety review, ASN issued the resolution of 30 November 2016 (amended on 26 June 2017) regulating the continued operation of the facility through technical prescriptions relating in particular to the improvement plan that CEA had undertaken to implement. Some of the CEA’s commitments have not been fulfilled within the deadlines. In particular, the licensee has requested pushing back of the deadlines for removal of the radioactive substances whose utilisation cannot be justified, and the implementation where necessary of measures to place and maintain the BNI in a safe condition in the event of fire in the areas adjacent to the nuclear areas. The decommissioning of Célimène (unit formerly intended for the examination of fuels from reactor EL3) is also concerned by this request. ASN is therefore still waiting for the CEA to submit a robust action plan. 64 ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2022 Regional overview of nuclear safety and radiation protection • ÎLE-DE-FRANCE •