At present about ten projects of this type are underway in the former facilities. They will span several decades and are a prerequisite to the complete decommissioning of these facilities, whereas the decommissioning of the process parts of the plant is continuing with more conventional techniques. 2.5 The support facilities (storage and processing 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 SaintLaurent-des-Eaux silos (BNI 74), the Orano plant silos in La Hague (silos 115 and 130 in BNI 38, the HAO silo in BNI 80), the pits and trenches of BNI 56 and the wells of BNI 72 and BNI 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 projected or in the course of construction. The Effluent Treatment Stations (STEs) for their part have been shut down due to their ageing or because the facilities producing the effluents treated in these STEs have stopped functioning. Examples include the Radioactive Effluent and Waste Treatment Station (STED) at Fontenay-aux-Roses, BNI 37-B at Cadarache, STE2 at the La Hague plant and the Brennilis’ STE. The difficulties associated with the decommissioning of the STEs are closely dependent on 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 old stored waste and of the sludge or deposits in the STE tanks. Secondly, the difficulty in accessing the waste for retrieval, which was not taken into consideration in the design (silos, trenches, concrete-lined pits, cramped premises, etc.), necessitating the costly construction of infrastructures in conformity with current safety requirements and leading to long retrieval times. A number of unforeseeable industrial setbacks are also encountered during these operations, leading to additional delays. 3 // ASN actions relating to facilities being decommissioned: a graded approach 3.1 The graded approach according to the risks of the facilities ASN ensures the oversight of facilities undergoing decommissioning, as it does for facilities in operation. The BNI System also applies to definitively shut down facilities. ASN implements an approach that is proportional to the extent of the risks or drawbacks inherent in the facility. The risks with facilities undergoing decommissioning differ from those for facilities in operation. For example, the risks of significant off-site discharges decrease as decommissioning progresses because the quantity of radioactive substances decreases. Consequently, the requirements relating to the control of risks and drawbacks are proportionate to the risks borne by the facilities. ASN thus considers that it is generally inappropriate to start significant reinforcement work on a facility undergoing decommissioning, on condition that the decommissioning operations reduce the sources of danger in the short term. 3.2 The periodic safety reviews of facilities undergoing decommissioning Given the diversity of the facilities and the situations in question, each periodic safety review necessitates an appropriate examination method. Some facilities undergoing decommissioning warrant particular attention owing to the risks they present and may be reviewed by the GPDEM. For others presenting a lower level of risk, the extent of the inspections and examinations is adapted accordingly. In 2021, ASN continued the examination of the safety review reports of some twenty facilities undergoing decommissioning that have been received since 2015. Inspections focusing on the periodic safety review were conducted in 2021 on four facilities undergoing decommissioning. These inspections are used to check the means implemented by the licensee to carry out its review, as well as compliance with the action plan resulting from its conclusions. They led to several requests for corrective action and additional information. In 2021, ASN rendered public its conclusions on the safety review of the GCRs (BNIs 45, 46, 133, 153 and 161), of Superphénix (BNI 91), of Rapsodie (BNI 25), of the MCMF facility (BNI 53), of the Cadarache storage yard (BNI 56), of the ATUe’s (BNI 52) and AMI Chinon (BNI 94). 3.3 Financing decommissioning: ASN’s opinion on the triennial reports The regulatory framework for ring-fencing the funds necessary for management of the long-term decommissioning and waste management expenses is presented in point 1.4. On 13 August 2020, ASN published opinion CODEP-CLG-2020- 040124 of 6 August 2020 relative to the examination of the threeyearly reports submitted in 2019 by the licensees, concerning the accounts closed at the end of 2018. The next triennial reports will be submitted in 2022. ASN notes that the scope of evaluation of the expenses remains incomplete and omits certain high-stake financial operations. More specifically, the licensees are vague about the financing of the decommissioning preparation operations, and do not take into account in their cost assessment the characterisation and management of pollution of soils and structures, the complete clean-out and remediation operations, or the costs of works to maintain the facilities over their entire lifetime. ASN also underlines that the assumptions adopted for evaluating the complete costs must be reassessed in order to show reasonable caution in the scheduling of the decommissioning projects and programmes, taking account of the risks related to the unavailability of storage, treatment and disposal facilities. Furthermore, ASN considers that the projected costs at completion must be more detailed and more fully substantiated, particularly in the light of the observed state of progress of the projects, as falling behind in the decommissioning schedules can raise the costs at completion. 338 ASN Report on the state of nuclear safety and radiation protection in France in 2021 13 – DECOMMISSIONING OF BASIC NUCLEAR INSTALLATIONS
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