Abstracts ASN Report 2021

THE CEA FONTENAY-AUX-ROSES SITE Created in 1946 as the CEA’s f irst research centre, the Fontenay-aux-Roses site is continuing its transition from nuclear activities towards research activities in living sciences. The CEA Fontenay‑aux‑Roses site, part of the CEA Paris‑Saclay centre since 2017, comprises two BNIs, namely Procédé (BNI 165) and Support (BNI 166). BNI 165 accommodated the research and development activities on nuclear fuel reprocessing, transuranium elements, radioactive waste and the examination of irradiated fuels. These activities were stopped in the 1980s-1990s. BNI 166 is a facility for the characterisation, treatment, reconditioning and storage of legacy radioactive waste from the decommissioning of BNI 165. Broadly speaking, the CEA’s decommissioning and waste management strategy has been examined by ASN, which stated its position in May 2019 on the priorities def ined by the CEA (see chapter 13 of the full ASN Report). Decommissioning of the Fontenay‑aux‑Roses site includes priority operations because it presents particular risks, linked f irstly to the quantity of radioactive waste present in the facilities, and secondly to the radiological contamination of the soils under part of one of the BNI 165 buildings. In addition to this, the Fontenay‑aux‑Roses centre, which is situated in a densely-populated urban area, is engaged in an overall delicensing process. Procédé and Support facilities Decommissioning of the two facilities Procédé and Support, which constitute BNI 165 and BNI 166 respectively, was authorised by two Decrees of 30 June 2006. The initial planned duration of the decommissioning operations was about ten years. The CEA informed ASN that, due to strong presumptions of radioactive contamination beneath one of the buildings, to unforeseen difficulties and to a change in the overall decommissioning strategy of the CEA’s civil centres, the decommissioning operations had to be extended and that the decommissioning plan would be modified. In June 2015, the CEA submitted an application to modify the prescribed deadlines for these decommissioning operations. ASN deemed that the first versions of these decommissioning decree modif ication application f iles were not admissible. In accordance with the commitments made in 2017, the CEA submitted the revised versions of these f iles in 2018. These f iles were supplemented over the 2019‑2021 period, particularly with respect to the planned decommissioning operations and their schedule. The CEA forecasts end of decommissioning of the BNIs beyond 2040, perhaps even 2050 in the case of BNI 165. The two draft decommissioning decree modifications are under examination. The new decrees will set the decommissioning characteristics, notably their completion time frame. Assessment of the CEA Fontenay-aux-Roses site The licensee must maintain its efforts to ensure the operational safety of its facilities. Safety is considered acceptable, even if areas for improvement have been identified in a number of technical subjects. The points requiring particular attention concern more specifically control of the lightning-related risk for BNI 165 and the prolonged unavailability of the fire extinguishing systems of the shielded systems of said BNI. The management process for noteworthy modifications of the facilities is appropriate. Tracking of the maintenance and inspections of the power generating sets must nevertheless be improved. The CEA also reported one environment-related significant event in 2021, following the discovery of legacy pollution in an inspection port linked to old pipes of the CEA Fontenay-aux-Roses site effluents system (traces of plutonium in sediments). ASN conducted a reactive inspection on this subject. The CEA took action to remove the pollution, which included cleaning operations and post-clean-out inspection. In the light of the elements given to ASN by the CEA, no consequences for people or the environment have been identified. Broadly speaking, ASN concedes that the CEA is encountering real technical difficulties in retrieving the legacy waste currently stored in these facilities, but it again underlines the delays in performing the studies and in the scheduling of these projects. In 2021, as in the preceding year, the CEA presented ASN its forecasts concerning the coordination of the studies and work planned on the site to reduce the “dispersible inventory” within the facilities. The new organisation deployed since September 2020 for the periodic safety reviews and work on the facility decommissioning files is found to be robust but must continue to prove its effectiveness. ASN expects the CEA to continue to implement proactive measures to control and render reliable the time frames associated with these projects, particularly the deadlines announced for the submission of the decommissioning worksite preparatory studies. ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2021 71 REGIONAL OVERVIEW OF NUCLEAR SAFETY AND RADIATION PROTECTION ÎLE-DE-FRANCE