LES ACTIVITÉS NUCLÉAIRES : RAYONNEMENTS IONISANTS ET RISQUES POUR LA SANTÉ ET L’ENVIRONNEMENT 2.5 The support facilities (storage and treatment of radioactive effluent and waste) Many of these facilities, most of which were commissioned in the 1960’s and whose level of safety does not comply with current best practices, have been shut down. Old storage facilities were not initially designed to allow the removal of the waste, and in some cases they were seen as being the definitive waste disposal site. Examples include the silos at Saint-Laurentdes-Eaux (BNI 74), the pits, trenches and hangars of BNI 56, and the shafts of BNIs 72 and 166. Retrieval of the waste from these facilities is complex and will span several decades. The waste must then be packaged and stored again in safe conditions. New packaging and storage facilities are thus either planned or actually under construction. The STEs for their part have been shut down due to their ageing or because the facilities producing the effluents treated in these stations have stopped functioning. Examples include BNI 37-B at Cadarache. The difficulties associated with decommissioning of the STEs are closely linked to their shutdown conditions, particularly the emptying and rinsing of their tanks. The decommissioning of these support facilities raises many issues. Firstly, poor knowledge of the operating history and the state of the facility to be decommissioned (taking account of the corrosion of waste drums or pollution of soils resulting from significant events that occurred when in service, for example) necessitates prior characterisation of the stored legacy waste and of the sludges or deposits present in certain tanks and silos. Moreover, taking into account the quantities, the physical and chemical forms and the radiotoxicity of the waste contained in these facilities, the licensee must develop means and skills that involve complex engineering techniques (radiation protection, chemistry, mechanics, electrochemistry, robotics, artificial intelligence, etc.). In fact, this waste is highly irradiating and heterogeneous, as it comprises structural elements from fuel reprocessing, technological waste, rubble, soils and sludge. Some of the waste has been stored in bulk with no prior sorting. The retrieval operations therefore require remotely operated pick-up means, conveyor systems, sorting systems, sludge pumping and waste packaging systems. The development of these means, carrying out the operations under conditions ensuring a satisfactory level of safety and radiation protection and perhaps even the creation of new WRP facilities represent a major challenge for the licensee. Given that these operations can last several decades, the management of ageing of the facilities is also a challenge. HIGHLIGHT No.3 Extension of the operation of three evaporators in the HAPF facility at BNI 33 The High Activity Fission Products (HAPF) facility at BNI 33 contains evaporators that were used to purify the acid solutions used to dissolve irradiated nuclear fuels in order to extract their components, or to rinse equipment. This purification was necessary to make the acid solutions compatible with treatment. As part of the plant’s decommissioning, some process equipment still needs to be rinsed with acid solutions before it can be decommissioned. Evaporators are therefore needed to purify these solutions until the rinsing operations are complete. As the solutions treated in the evaporators are highly acidic, the constituent materials of this equipment are subject to very significant corrosion phenomena. The BNI 33 decommissioning file submitted for public enquiry at the end of 2020, on which the amended decommissioning Order of 8 November 2013 is based, stipulated that the rinsing operations and the use of the evaporators should be completed by 31 December 2024. However, the schedules for rinsing and decommissioning operations at BNI 33 have been delayed for various technical reasons. As a result, rinsing could not be completed before 31 December 2024. Orano has therefore asked ASNR for authorisation to extend, for a period of seven years, the operation of the three evaporators in the HAPF facility that it still needs to complete the purification of the acid solutions used for rinsing prior to decommissioning of the equipment. The ASNR review of this request highlighted a number of technical issues, in particular the need to take account of localised corrosion phenomena in the in-service monitoring of the evaporators. Based on the information currently available on the condition of the three evaporators in the HAPF facility, they could be restarted for one operating cycle only, representing around one hundred days of actual operation. An extension beyond one operating cycle will require additional information, particularly concerning localised corrosion phenomena. As a result, at the end of November 2025, ASNR granted authorisation for three evaporators in the HAPF facility to restart for one operating cycle, and stipulated technical requirements with respect to this restart. ASNR Report on the state of nuclear safety and radiation protection in France in 2025 343 11 13 12 A / Z 10 09 08 01 05 02 06 03 07 04
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