Abstracts ASN Report 2021

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 def initively shut down in March 2019. Following submission of the decommissioning f ile 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. 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. Control of the f ire risk is characterised by good f ire permit management and constructive improvement measures in view. However, the monitoring of fire loads, especially the waste accumulated in the facility, is inadequate. The monitoring of outside contractors performing the periodic inspections and tests is not sufficiently formalised. The electrical equipment maintenance operations are performed correctly, despite some shortcomings in the verifications performed by outside contractors. Improvements are expected in the follow-up of the recommendations for protection against lightning-related risks. Management of the decommissioning preparation operations is satisfactory from the technical aspects, but delays are observed, as in the previous years. ASN considers that the licensee must be attentive to control of the decommissioning preparation operations and improving waste management. 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. Based on the facility inspections and monitoring carried out in 2021, ASN considers that the level of safety of the Orphée reactor is on the whole satisfactory. Nevertheless, some aspects in the management of radioactive sources and pressure equipment require particular attention, and individual assessments of exposure to ionising radiation at the work station must be established. The management of fire loads, the management of a waste storage area and the conformity of waste zoning must be improved. Although the preparation of the decommissioning preparation operations is satisfactory, delays are observed. Progress in fulf illing the commitments following the periodic safety review is satisfactory. The significant events nevertheless show that vigilance is required with the organisation of equipment maintenance. 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 fulf illed within the deadlines. In particular, the CEA has requested pushing back of the deadlines for removal of the radioactive substances whose utilisation cannot be justif ied, and for 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. In the years to come, BNI 72 will no longer accept irradiating waste from the CEA Saclay site. Consequently, the CEA has started the clean-out work on a unit of the LECI which will be dedicated to the overpacking of the waste from BNI 50. ASN will check the progress of the associated work. Operational management of the Organisational and Human Factors (OHF) is satisfactory, despite a high staff turnover. Improvements are however expected in the management of the criticality risk, in the integration of the lightning-related risk and the monitoring of outside contractors, notably with the adaptation of the BNI monitoring programme to the activities entrusted to these contractors. 66 ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2021 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION