ASN Report 2017

456 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 16  - Radioactive waste and contaminated sites and soils reminded Areva of the need to define and finalise solutions for packaging this waste within time frames that enable the 2030 deadline to be met. These solutions will require the prior approval of ASN in accordance with the provisions of Article 6.7 of the Order of 7th February 2012 (see point 1.2.2). Within the framework of the waste retrieval and packaging operations, Areva NC is examining packaging solutions that necessitate the development of new processes, particularly for the following IL-LL waste: ཛྷ ཛྷ the sludge from the STE2 facility; ཛྷ ཛྷ the alpha technological waste coming primarily from the La Hague and MELOX plants, which is not suitable for surface disposal. For other types of IL-LL waste resulting from the waste retrieval and packaging operations, Areva NC is examining the possibility of adapting existing processes (compaction, cementation, vitrification). Part of the associated packaging baseline requirements are currently being examined by ASN. Facilities operated by Areva The waste management strategy of Areva is based essentially on the La Hague site. This site is presented in chapter 13 covering fuel cycle installations. ཛྷ ཛྷ Ecrin (BNI 175) The Areva NC plant on the Malvési site transforms the concentrates from the uranium mines into uranium tetrafluoride. The transformation process produces liquid effluents containing nitrated sludge loaded with natural uranium. These effluents are settled and evaporated in ponds. The sludge is stored in ponds and the supernatant is evaporated in evaporation ponds. The entire plant is subject to the Seveso high-threshold ICPE System. The Ecrin facility was authorised by Decree of 20th July 2015 for the storage of radioactive waste for a period of thirty years with a volume of waste not exceeding 400,000 m 3 and total radiological activity of less than 120 terabecquerels. It comprises two sludge storage ponds (B1 and B2) for sludge from the Areva NC plant on the Malvési site. These ponds alone are subject to the BNI System due to the presence of traces of artificial radioisotopes from the processing of reprocessed uranium from the Marcoule site. Ponds B1 and B2 have not been used for the settling of liquid effluents since the B2 pond embankment failed in 2004 (utilisation prohibited by Prefectural Order). Once commissioned, BNI 175 situated on the site of ponds B1 and B2 will also contain the solid residues from the Malvési site’s ponds B5 and B6, which will be emptied when the facility enters service. Ponds B1 and B2 and their content will be covered with a bituminous cover. Areva applied for commissioning authorisation on 15th October 2015. This application was supplemented on 2nd June 2016 and is currently being examined by ASN. ASN will adopt a position on this application in 2018, provided that Areva NC has submitted the last additional information requested. ASN is particularly attentive to the stability of the embankments and their earthquake resistance, and the safety of the work involved in the transfer of the sludge, the filling of the compartment and the laying of the bituminous cover. Within the framework of the PNGMDR, ASN asked Areva to study the different long-term disposal options for the waste contained in the Ecrin BNI. These studies are currently being examined. 1.4.3 EDF waste management EDF waste management strategy The waste produced by EDF Nuclear Power Plants (NPP) is activated waste (from reactor cores) and waste resulting from their operation and maintenance. Some legacy waste and waste resulting from ongoing decommissioning operations can be added to this. EDF is also the owner, for the share attributed to it, of HL and IL-LL waste resulting from spent fuel reprocessing in the Areva NC La Hague plant. Activated waste This waste notably comprises control rod assemblies and poison rod assemblies used for reactor operation. This is IL-LL waste that is produced in small quantities. This waste is currently stored in the NPP pools pending transfer to the Iceda facility. Operational and maintenance waste Some of the waste is processed by the Centraco facility in Marcoule in order to reduce the volume of ultimate waste. The other types of operational and maintenance waste are packaged on the production site then shipped to the CSA or Cires repositories for disposal (see points 1.3.1 and 1.3.2). This waste contains beta and gamma emitters, and few or no alpha emitters. At the end of 2013, EDF submitted a file presenting its waste management strategy. This file was examined by the competent Advisory Committees of Experts in 2015. Further to this examination, ASN asked EDF more specifically in 2017 to continue its measures to reduce the uncertainties concerning the activity of the waste sent to the CSA, to improve its organisational arrangements to guarantee the allocation of adequate resources to radioactive waste management, and to present the most appropriate process for the treatment of used steam generators. The issues and implications The main issues related to the EDF waste management strategy concern the management of legacy waste and changes linked to the fuel cycle. ཛྷ ཛྷ The management of legacy waste primarily concerns structural waste (graphite sleeves) from the graphite- moderated gas-cooled reactor fuels. This waste could be disposed of in a repository for LLW-LL waste (see point 1.3.4). It is stored primarily in semi-buried silos at Saint-Laurent-des-Eaux. Graphite waste is also present in the form of stacks in the gas-cooled reactors currently being decommissioned.