Operations carried out in the plants The reprocessing plants comprise several industrial units, each intended for a particular operation. Consequently, there are facilities for the reception and storage of spent fuel assemblies, for their shearing and dissolution, for the chemical separation of fission products, uranium and plutonium, for the purification of uranium and plutonium, for treating the effluents and for packaging the waste. When the spent fuel assemblies arrive at the plants in their transport casks, they are unloaded either “under water” in the spent fuel pool, or “dry” in a leak-tight shielded cell. The fuel assemblies are then stored in pools to cool them down. They are then sheared and dissolved in nitric acid to separate the pieces of metal cladding from the spent nuclear fuel. The pieces of cladding, which are insoluble in nitric acid, are removed from the dissolver, rinsed in acid and then water, and transferred to a compacting and packaging unit. The nitric acid solution comprising the dissolved radioactive substances is then processed in order to extract the uranium and plutonium and leave the fission products and other transuranic elements. After purification, the uranium is concentrated and stored in the form of uranyl nitrate (UO2(NO3)2). It will then be converted into a stable solid compound (U3O8) in the TU5 facility on the Tricastin site. The uranium resulting from this process is called “reprocessed uranium”. After purification and concentration, the plutonium is precipitated by oxalic acid, dried, calcined into plutonium oxide, packaged in sealed containers and stored. The plutonium is then used for the fabrication of MOX (Mixed OXide) fuels in the Orano plant in Marcoule (Melox). The effluents and waste produced by the operation of the plants The fission products and other transuranic elements resulting from reprocessing are concentrated, vitrified and packaged in standard vitrified waste packages (CSD-V). The pieces of metal cladding are compacted and packaged in standard compacted waste packages (CSD-C). Furthermore, the reprocessing operations described in the previous paragraph involve chemical and mechanical processes which produce gaseous and liquid effluents and solid waste. The solid waste is packaged on site by either compaction or encapsulation in cement. The solid radioactive waste resulting from the reprocessing of the spent fuel assemblies from French reactors is, depending on its composition, either sent to the Aube repository (CSA) or stored on the Orano Recyclage La Hague site until a definitive disposal solution is found (particularly the CSD‑V and CSD‑C packages). In accordance with Article L. 542-2 of the Environment Code, radioactive waste from the reprocessing of spent fuels of foreign origin is shipped back to its owners. It is, however, impossible to physically separate the waste according to the fuel from which it originates. In order to guarantee an equitable distribution of the waste resulting from the reprocessing of the fuels of its various customers, the licensee has proposed an accounting system that tracks the entries into and exits from the La Hague plant. This system, called “EXPER”, was approved by the Order of 2 October 2008 of the Minister responsible for energy. The gaseous effluents are released mainly when the fuel assemblies are sheared and during the dissolution process. These gaseous effluents are treated by washing in a gas treatment unit. The residual radioactive gases, particularly krypton and tritium, are checked before being discharged into the atmosphere. The liquid effluents are treated and usually recycled. Some radionuclides, such as iodine and tritium, are directed, after monitoring, to the sea discharge outfall. This outfall, like the other outfalls on the site, is subject to discharge limits. The other effluents are routed to the site’s packaging units (solid glass or bitumen matrix). FINAL SHUTDOWN AND DECOMMISSIONING OPERATIONS ON CERTAIN FACILITIES The former spent fuel reprocessing plant UP2‑400 (BNI 33) was commissioned in 1966 and has been definitively shut down since 1 January 2004. Final shutdown also concerns three BNIs associated with the UP2‑400 plant: BNI 38 (which comprises the Effluents and solid waste treatment station No. 2 – STE2, and the Oxide nuclear fuel reprocessing facility No. 1 – AT1), BNI 47 (Radioactive source fabrication unit – ELAN IIB) and BNI 80 (HAO facility). Orano submitted two partial decommissioning authorisation applications for BNIs 33 and 38 in April 2018. The schedule push-backs requested by the licensee lead to decommissioning completion deadlines in 2046 and 2043 instead of 2035, the previous deadline prescribed for the two BNIs. Further to Orano’s additions to the file concerning firstly the elimination of the interactions between the MAPu facility and the plutonium BST1 facility in the event of an earthquake, and secondly the memorandum in response to the opinion of the Environmental Authority, a public inquiry was held from 20 October to 20 November 2020. At the end of the inquiry, the inquiry commission issued a favourable opinion. ASN issued an opinion on the draft decrees in July 2022. Decrees 2022-1480 and 2022-1481 dated 28 November 2022 were published in the Official Journal of 29 November 2022. ASNR notes that the schedule push-backs requested are significant and largely due to the delays in legacy Waste Retrieval and Packaging (WRP). Consequently, ASNR will continue to monitor the management of these projects in 2026. LEGACY WASTE RETRIEVAL AND PACKAGING OPERATIONS Unlike the direct on-line packaging of the waste generated by the new UP2-800 and UP3-A plants at La Hague, most of the waste generated by the first UP2-400 plant was stored in bulk without permanent packaging. The operations to retrieve this waste are complex and necessitate the deployment of substantial means. They present major safety and radiation exposure risks, which ASNR monitors with particular attention. The retrieval of the waste contained in the old storage facilities of the La Hague site is also a prerequisite for the decommissioning and clean-up of these facilities. Retrieval and packaging of the STE2 sludges The STE2 station served to collect the effluents from the UP2‑400 plant, to treat them and to store the precipitation sludges resulting from the treatment. The STE2 sludges are precipitates that fix the radiological activity contained in the effluents and they are stored in seven silos. A portion of the sludges has been encapsulated in bitumen and packaged in stainless steel drums in the STE3 facility. Following ASN’s banning of bituminisation in 2008, Orano studied other packaging methods for the non-packaged or stored sludges. The scenario for the retrieval and packaging of the STE2 sludges presented in 2010 was broken down into three steps: • retrieval of the sludges stored in silos in STE2 (BNI 38); • transfer and treatment, initially envisaged by drying and compaction, in STE3 (BNI 118); • packaging of the resulting pellets into “C5” packages for deep geological disposal. Normandie 76 ABSTRACTS – ASNR Report on the state of nuclear safety and radiation protection in France in 2025
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