Abstracts ASN Report 2021

The management of an accidental spillage situation, checked during an exercise, is appropriate and the various retention systems inspected are well kept. Some improvements are nevertheless required in the knowledge of hazardous substances volumes and the volumes to be contained. The labour inspections carried out in 2021 under national or local initiatives revealed some weaknesses in the site’s organisation and the correction of deviations, and in the management of risks of falling from height. They have also prompted the labour inspectorate to ask for additional information in several areas, such as the optimisation of radiation protection on work sites, the cleaning and filtration of the air in certain rooms presenting particular risks and the management of risks associated with the Covid-19 pandemic. Reactors A1 and A2 undergoing decommissioning The former Saint‑Laurent‑des‑Eaux NPP constitutes a BNI comprising two “integrated” GCRs, reactors A1 and A2. These first-generation reactors used natural uranium as the fuel, graphite as the moderator and were cooled by gas. Their f inal shutdown was declared in 1990 and 1992 respectively. Complete decommissioning of the installation was authorised by the Decree of 18 May 2010. On completion of the analysis of the periodic safety review concluding reports for all the GCRs, ASN indicated in December 2021 that it has no objection to the continued operation of BNI 46 (Saint‑Laurent reactors A1 and A2). It will verify during the examination of the new decommissioning files for these reactors, which are to be submitted by EDF in late 2022 to set out the new “in air” decommissioning strategy, that the decommissioning operations are carried out under suitable conditions of safety and radiation protection, within controlled time frames. In 2021, EDF resumed the decommissioning work sites that were stopped on account of the restrictions laid down to combat the Covid-19 pandemic. ASN considers that the level of safety of the Saint‑Laurent‑des‑Eaux A reactors is satisfactory. ASN’s inspections found that the overall upkeep of the premises and worksites was good. In addition, the organisation put in place to meet the commitments made further to the inspections and significant events is satisfactory, as is waste management. However, improvements are required in the management of fire-extinguishing waters and the traceability of the monitoring of outside contractors working in the facility. Saint‑Laurent‑des‑Eaux silos The facility, authorised by the Decree of 14 June 1971, consists of two silos whose purpose is the storage of irradiated graphite sleeves originating from the operation of Saint‑Laurent‑des‑Eaux A GCRs. Static containment of this waste is ensured by the concrete bunker structures of the silos, which are sealed by a steel lining, but whose behaviour in the event of an earthquake needs to be assessed. In 2010, EDF installed a geotechnical containment around the silos, reinforcing the control of the risk of dissemination of radioactive substances, which is the main risk presented by the installation. Operation of this BNI is limited to surveillance and upkeep measures: radiological monitoring inspections and measurements in the silos, checking there is no water ingress, checking the relative humidity, the dose rates around the silos, the activity of the water table, monitoring the condition of the civil engineering structures. In the context of the change of decommissioning strategy for the GCRs, EDF announced in 2016 its decision to start removing the graphite sleeves from the silos without waiting for a graphite waste disposal route to become available. To this end, EDF envisages creating a new graphite sleeve storage facility on the Saint‑Laurent‑des‑Eaux site. ASN is waiting for EDF to declare final shutdown of the facility. Submission of the decommissioning f ile, which will take into account the emptying, post-operational clean-out and demolition of the existing silos, is planned for the end of 2022. 56 ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2021 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION