ASN Report 2020

In 2020, ASN inspected the organisation and methodology put in place by the CEA for the conformity check of the facility against its applicable baseline requirements, and for the development and monitoring of the action plan resulting f rom the periodic safety review report. ASN expects an improvement in the action plan coordination and monitoring in order to reach the level of risk control that the CEA has undertaken to achieve as quickly as possible. The CEA must moreover, when necessary, put in place compensatory measures pending the upgrading of the BNI further to its periodic safety review. ASN underlines that projects that contribute to reducing the potential source term within facilities constitute priorities for safety. Alongside this, ASN’s inspections find the facility to be in good overall condition. ASN nevertheless observes inadequate management of scheduling of the regulatory periodic inspections of the handling cranes. Liquid effluents management zone – CEA Centre The liquid effluents management zone constitutes BNI 35. Declared by the CEA by letter of 27 May 1964, this facility is dedicated to the treatment of radioactive liquid effluents. The CEA was authorised by a Decree of 8 January 2004 to create “Stella”, an extension in the BNI for the purpose of treating and packaging low-level aqueous effluents from the Saclay centre. These effluents are concentrated by evaporation then immobilised in a cementitious matrix in order to produce packages acceptable by the French radioactive waste management agency’s (Andra) above- ground waste disposal centres. The concentration process was put into service in 2010, but the appearance of cracks in the first packages led ASN to limit the packaging operations. The CEA has only packaged some effluents from one of the installation’s tanks that contains 40 cubic metres (m 3 ) of concentrates. The CEA has since made progress in def ining its packaging solution for all the facility’s effluents. Thus, in June 2018, Andra authorised the packaging of these concentrates in accordance with the 12H package approval. In January 2020, the CEA obtained ASN’s authorisation to put this process into service. However, the first cementation tests on 12H packages carried out with inert effluents gave unsatisfactory results and were continued until the end of 2020. Complementary investigations concerning the stability of the structure of the low-level liquid effluents storage room (room 97) have led the CEA to suspend, since 2016, the acceptance of effluents from other BNIs. The majority of the low- and intermediate-level (LL and IL) radioactive effluents produced by the Saclay site production sources are now directed to the Marcoule Liquid Effluent Treatment Station (STEL), a Defence BNI. In November 2018, in accordance with its commitment, the CEA submitted to ASN a file presenting the management strategy for the liquid radioactive effluents from the CEA Île‑de‑France and the overall strategy concerning BNI 35. In this f ile the CEA has set out deadlines for the cementation of the legacy concentrates stored on the site, which is a priority for the facility. Alongside this, the situation of pit 99 containing old tanks of organic effluents, with the presence of contaminated sludge in the bottom of the tanks and the bottom of the pit, remains a major clean-out challenge. Tank clean-out and dismantling studies have been carried out. An application for authorisation to perform these operations is currently being examined by ASN. The Decree of 8 January 2004 authorising the creation of Stella also stipulated that the CEA must, within 10 years, remove the legacy effluents stored in the eight tanks called “MA500” and in tank HA4 of BNI 35. Due to the technical diff iculties encountered in their retrieval and packaging, these operations lasted longer than planned. The operations to empty the last MA500 tank could not be completed, even though the licensee has good technical knowledge of the physical and chemical issues associated with the emptying of this tank. ASN is therefore waiting for the CEA to submit an action plan to complete the emptying of this tank. The inspections carried out in 2020 evidenced good management of the facility’s baseline requirements. ASN does however observe shortcomings in the monitoring and upkeep of the electrical installations of the BNI. Improvements are also expected in the recording of the requalification analyses and Control of urban development around the Saclay site In view of the changes in the Basic Nuclear Installations (BNIs) of the French Alternative Energies and Atomic Energy Commission (CEA) and CIS bio international, ASN had asked the CEA and CIS bio international to update their safety assessments in order to update the hazard zones defined around the BNIs. These updates, which take into account the shutdown of the Orphée reactor and removal of the iodine-131 from the CIS bio international facility, show an effective reduction in the risks induced by the site’s BNIs. The examination carried out by ASN confirms these results, making it possible to revise the provisions for controlling urban development. Thus, applying a cautious approach to the urban development around a nuclear site where decommissioning activities present safety risks and are going to last for several years, the Prefect of the Essonne département has updated the Applicable Public information Notice by maintaining a land-use planning zone over a perimeter of 250 metres starting from the Saclay site fences. The CEA – Saint Aubin station project on the route of the future line 18, which is situated at the Christ de Saclay roundabout, is now compatible with the proposed new urban development restrictions. ASN Report on the state of nuclear safety and radiation protection in France in 2020 69 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION ÎLE-DE-FRANCE