4. Assessment of the licensees’ decommissioning strategies 4. Part of the inventory of the radionuclides of a nuclear facility that groups the radionuclides that could be dispersed in the facility in the event of an incident or accident, or even, for a fraction of them, be released into the environment. 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 the 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 priority 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 14. 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, which may also be revised if it turns out in the coming decades that this scenario can be optimised in view of acquired experience. This decommissioning strategy for the GCRs is governed by two ASN resolutions, 2020-DC-0686 and CODEP-CLG-2020-021253, published on 3 March 2020. These resolutions set the next steps required for the change of decommissioning strategy, notably the defining of a robust strategy for managing graphite waste, the decommissioning operations to continue over the next few years and the information to be transmitted to ASN to check effective implementation of the strategy. EDF also commissioned its graphite industrial demonstrator at Chinon in 2022. ASN considers that it is appropriate for EDF to develop an industrial demonstrator before decommissioning the reactor pressure vessels, but decommissioning of the various reactors must nevertheless begin within reasonable time frames in view of the obligation for decommissioning to be carried out as rapidly as possible. Regarding the other shut down EDF facilities (notably Chooz A, AMI Chinon, EL4-D and Superphénix), their decommissioning is under way and on the whole is meeting the objective of achieving as short a time frame. 4.2 Assessment of Orano’s decommissioning strategy The decommissioning of old installations is a major challenge for Orano, which has to conduct several large-scale decommissioning projects over variable time scales (UP2-400 facility at La Hague, Eurodif Production plant, individual facilities of the DBNI at Pierrelatte, etc.). Implementation of decommissioning is closely linked to the radioactive waste management strategy, given the quantity and the non-standard and hard to characterise nature of the waste produced during the prior operations phase and the new waste resulting from the decommissioning operations. Furthermore, Orano must carry out special WRP operations in old waste storage facilities. The deadlines for completion have been stipulated by ASN, particularly for the La Hague site. Completion of these WRP operations governs the progress of decommissioning on the UP2-400 plant, as WRP is one of the first steps of its decommissioning. The WRP work is of particular importance given the inventory of radioactive substances present and the age of the facilities in which they are stored, which do not meet current safety standards. In addition, WRP projects are considerably complex owing to the interactions with the plants in operation on the site. Further to the difficulties observed in the examination of files relating to the WRP and decommissioning operations at the Orano La Hague site and failure to perform the operations within the prescribed deadlines, ASN and Orano agreed to set up regular monitoring in order to foresee and address any blocking situations and determine practical measures to put in place to accomplish the WRP and decommissioning operations in the shortest time frame possible. In June 2016, at the request of ASN and the Defence Nuclear Safety Authority (ASND), Orano submitted its decommissioning and waste management strategy. The file also includes the application of this strategy on the La Hague and Tricastin sites. In its position statement letter of 14 February 2022, ASN underlined the licensee’s progress in assimilating the objectives of immediate dismantling, in tracking the governance of complex projects, the progress of the operations of several Tricastin facilities, and the defining of the definitive waste packaging processes for the La Hague site. ASN nevertheless considers that Orano should prioritise the implementation of its decommissioning and waste management strategy according to the risks, and more specifically better manage its WRP strategy in order to reduce the “dispersible radiological inventory”(4) as early as possible. ASN also considers that Orano should improve its knowledge of the current state of the facilities with a view to their future post-operational cleanout and progressing in the management of complex projects. ASN Report on the state of nuclear safety and radiation protection in France in 2022 351 • 13 • Decommissioning of Basic Nuclear Installations 13 01 07 08 AP 04 10 06 12 14 03 09 05 11 02
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