ASN Report 2023

1.3.2 Low and intermediate-level, short-lived waste Low-level and intermediate-level short-lived waste (LL/ILW-SL) – in which the radioactivity comes primarily from radionuclides with a half-life of less than 31 years – results essentially from the operation of nuclear facilities and more specifically from maintenance activities (clothing, tools, filters, etc.). It can also come from the post-operational clean-out and decommissioning of these facilities. The majority of LL/ILW-SL waste is placed in surface disposal facilities operated by Andra. Once these facilities are closed, they will be monitored for a period set at 300 years by Basic Safety Rule RFS-I.2. The facility safety analysis reports – which are updated periodically, including during the monitoring phase – must show that at the end of this phase, the activity contained in the waste will have reached a residual level such that human and environmental exposure levels are acceptable, even in the event of a significant loss of the containment properties of the facility. There are two facilities of this type in France, the Manche repository (CSM – BNI 66), which operated from 1969 until 1994 and is currently in the closure preparation phase, and the Aube repository (CSA – BNI 149) which is in operation (see “Regional overview” in the introduction to this report). The quantity of LL/ILW-SL waste at the CSA amounted to 371,304 m3 at the end of 2022, representing 37% of the facility’s maximum authorised capacity. This quantity is supplemented by the waste emplaced in the CSM, or 527,225 m3. Therefore, the total quantity of LL/ILW-SL waste stored in Andra’s facilities is 898,529 m3, to be compared with the amount produced at the end of 2021, which was 981,000 m3. According to the data in the national inventory drawn up by Andra, these waste will represent a maximum volume of 2,000,000 m3, following the decommissioning of the existing installations. According to the estimates made by Andra in 2016 at the time of the second periodic safety review of the CSA, this facility could reach its maximum filling capacity by 2060 instead of 2042 as initially forecast, this new estimate being based on better knowledge of the future waste and the waste delivery schedules. 1.3.3 Low-level long-lived waste The low-level long-lived waste (LLW-LL) waste initially comprised two main types: graphite waste resulting from operation of the Gas-Cooled Reactors (GCRs) and radium-bearing waste from the radium industry and its offshoots. Other types of waste have been added to this category such as certain bituminised wastes, substances containing radium, uranium and thorium with low specific activity, as well as certain disused sealed radioactive sources. Furthermore, a fraction of the waste from the Écrin facility (BNI 175) operated by Orano in Malvési (Aude département), produced as from 1 January 2019, is now included in this waste category. The solid waste produced until 31 December 2018, on account of the large volumes it represents, is placed in a specific category of the national inventory called “RTCU” (French acronym standing for “Uranium Fuel Reprocessing Residues”). Putting in place a definitive management solution for this waste is one of the objectives defined by the Act of 28 June 2006. Finding such a management solution necessitates firstly having greater knowledge of LLW-LL waste and secondly conducting safety studies on the associated disposal solution. The successive PNGMDRs have set out this objective. ASN also drafted a notice in 2008 giving general safety guidelines concerning the search for a site capable of accommodating LLW-LL. This notice defines the general guidelines to follow as from the phases of looking for a site and designing an LLW-LL waste disposal facility in order to ensure its safety after closure. The PNGMDR 2010-2012 opened up the possibility of separate disposal of graphite waste and radium-bearing waste, and asked Andra to work on two design options: ∙ reworked cover disposal in an outcropping geological layer by excavation followed by backfilling; ∙ intact cover disposal dug in an underground layer of clay at a greater depth. Implementation of the requirements of the PNGMDR 2013‑2015 enabled the holders of LLW-SL waste to move forward with characterising their waste and studying the treatment possibilities, particularly as concerns the graphite wastes and certain bituminous waste packages. More specifically, the radiological inventory for chlorine-36 and iodine-129 has undergone a downward reassessment. Alongside this, Andra submitted a report in July 2015 containing: ∙ proposals of choices of management scenarios for graphite waste and bituminous waste; ∙ preliminary design studies covering the disposal options referred to as “intact cover disposal” and “reworked cover disposal”; ∙ the inventory of the waste to be emplaced in it and the implementation schedule. In 2016, ASN issued an opinion 2016-AV-264 on this report and began a revision of the general safety guidelines notice of 2008, which will ultimately be replaced by an ASN guide. To this end, a working group bringing together ASN, the French Institute for Radiation Protection and Nuclear Safety (IRSN), Andra, the LLW-LL waste producers and representatives of civil society was set up. The recommendations of the IRSN report published in December 2020 and summarising the work were examined by the Advisory Committee of Experts (GPE) in March 2021. On this basis, ASN began technical discussions with Andra and IRSN in 2021, focusing in particular on the assessment of the longterm dosimetric impact of the disposal project. In 2011 (as part of the PNGMDR 2013-2015 preparatory work) Orano submitted a study concerning the long-term management of the waste already produced by the Malvési site (known as “RTCU”), currently stored in the Écrin facility (BNI 175). Various disposal concepts are being envisaged: ∙ above-ground disposal; ∙ near-surface (40 m), reworked cover disposal, in the former open-cast mine pit; ∙ near-surface (40 m) reworked cover disposal, in a new pit. Given the nature of the waste and the configuration of the site, ASN indicated in its opinion 2012-AV-0166 of 4 October 2012 that it was not in favour of continuing the development of an above-ground disposal facility, as it considers that it does not meet the long-term safety requirements. Since then, Orano has abandoned the option of an above-ground disposal facility. On 2 September 2019, ASN issued its opinion on the studies required by Article 7 of the Decree of 27 December 2013 relative to the implementation of a final management solution for the Malvési legacy waste in a near-surface repository. In 2021, pursuant to Article 7 of the Decree of 20 July 2015, authorising the creation of BNI 175 Écrin, Orano submitted a report to ASN presenting the progress of studies and investigations conducted. Two disposal options envisaged for the radioactive waste on the Malvési site and its immediate environment are being considered. This report, which helped consolidate the waste inventories and acquired knowledge on the site’s geological formations, is currently being reviewed. ASN opinion 2020-AV-0357 of 6 August 2020 details the areas of work it recommends for the management of LLW-LL waste. ASN Report on the state of nuclear safety and radiation protection in France in 2023 373 • 15 • Radioactive waste and contaminated sites and soils 15 05 08 11 04 14 06 07 13 AP 03 10 02 09 12 01

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