02 03 04 05 06 07 08 09 10 11 12 13 01 3 ASN actions related 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. More specifically, 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 impacts are proportionate to the risks inherent in 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. 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. 3.3 Financing decommissioning: ASN’s opinion on the three-yearly 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. In 2022, ASN examined the three-yearly reports submitted by the licensees, regarding the accounts closed at the end of 2021. It published opinion CODEP-CLG-061286 of 14 December 2022 and sent its observations to the Ministry responsible for energy. The next three-yearly reports will be submitted in 2025. More generally, ASN notes that the evaluation perimeter of the expenses considered in the majority of these reports must be supplemented because it does not take into account certain operations that could represent major financial issues, particularly the decommissioning preparation operations. Moreover, ASN considers that the initial states of the sites at the beginning of their decommissioning must be described more precisely, taking account of any pollution present in the soils and structures and evaluating the associated clean-out costs. In effect, the assumptions concerning the initial state of the sites are not sufficiently robust on the whole, whereas it is of fundamental importance to have sound knowledge of the state of the sites in order to evaluate the decommissioning expenses conservatively. Lastly, ASN underlines that the assumptions adopted for evaluating the complete costs must be reassessed in order to exercise reasonable prudence in the scheduling of the decommissioning projects and programmes, taking account of the risks related to the unavailability of storage, treatment and disposal facilities. 4 Assessment of the licensees’ decommissioning strategies In a context in which numerous facilities have been shut down for several decades, with concomitant loss of knowledge of the facilities, ageing structures and in some cases large quantities of waste still present, maintaining good progress with the decommissioning operations is of major importance for the safety of these facilities. Yet ASN has noted that the majority of these operations are falling significantly behind schedule. ASN therefore regularly asks CEA, EDF and Orano to present their decommissioning and radioactive waste management strategies, thereby providing an overall view of the decommissioning projects and the management routes necessary for removal of the radioactive waste resulting from the decommissioning operations. As far as decommissioning is concerned, the licensees must justify the levels of priority assigned to the planned operations, principally through safety analyses. This prioritisation provides a means of checking that even if some projects are substantially behind schedule, the most significant resources will be devoted to operations with higher risk implications. With regard to radioactive waste management, ASN checks the consistency of the planned actions with the regulatory framework and the guidelines of the PNGMDR. The assessment of the radioactive waste management strategies is presented in chapter 15. 4.1 Assessment of EDF’s decommissioning strategy The first decommissioning strategy file for the EDF reactors definitively shut down (Chinon A1, A2, A3, Saint-Laurent A1 and A2, Bugey 1, EL4-D, Chooz A and Superphénix) was transmitted in 2001 at the request of ASN. Immediate dismantling was adopted as the reference strategy. This strategy has been updated regularly, in order to adjust the decommissioning schedule or incorporate the complementary studies requested by ASN and elements concerning the future decommissioning of the reactor fleet in service. For the six first-generation GCRs (Chinon A1, A2 and A3, Saint‑Laurent A1 and A2, and Bugey 1), EDF informed ASN of a complete change of strategy in March 2016, calling into question the technical principle (decommissioning “under water”) chosen for the decommissioning of these reactors and the phasing of the operations, resulting in the decommissioning of all the GCRs being pushed back by several decades. ASN will rule on the decommissioning time frames put forward by EDF in the decommissioning files submitted at the end of 2022 (currently being reviewed by ASN), which may also be revised if it turns out in the coming decades that this scenario can be optimised in the light of the OEF acquired. This GCR decommissioning strategy is regulated by two ASN resolutions (resolution 2020-DC-0686 and ASN Chairman’s resolution CODEP-CLG-2020-021253 of 3 March 2020). ASN Report on the state of nuclear safety and radiation protection in France in 2024 367 Decommissioning of Basic Nuclear Installations 14 15 AP
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