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 generally recycled. After verification and, in accordance with the discharge limits, certain radionuclides, such as iodine and tritium, are sent to the marine outfall pipe. The other effluents are routed to on-site packaging units (solid glass or bitumen matrix). The solid waste is packaged on-site, either by compacting, or by encapsulation in cement, or by vitrification. The solid radioactive waste from the reprocessing of spent fuel assemblies from French reactors is, depending on its composition, either sent to the low level and intermediate-level, short-lived waste (LLW/ILW-SL) repository at Soulaines (see chapter 14) or stored on the Orano site at La Hague, pending a final disposal solution (in particular the CSD-V and CSD-C). 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 System”, was approved by the Order of the Minister responsible for energy of 2 October 2008. 1.4 “Fuel cycle” consistency in terms of nuclear safety and radiation protection The “nuclear fuel cycle” comprises the fabrication of the nuclear fuel used in the nuclear power plant reactors, its storage and its reprocessing after irradiation. Several licensees are involved in the cycle: Orano, Framatome, EDF and the French National Agency for Radioactive Waste Management (Andra). ASN monitors the overall consistency of the industrial choices made with regard to fuel management and which could have consequences for safety. In this context, ASN periodically asks EDF to submit a “Cycle Impact” file prepared jointly with the “cycle” stakeholders and presenting the consequences –for each step of the “fuel cycle”– of EDF’s strategy for use of the different types of fuel in its reactors. ASN delivered its opinion of the “2016 Cycle Impact” file on 18 October 2018, the main conclusions of which are as follows. ASN underlines the need to anticipate any strategic change in the functioning of the “fuel cycle” by at least ten years so that it can be designed and carried out under controlled conditions of safety and radiation protection. This for example entails ensuring that –given the incompressible development times for industrial projects– the need for the creation of new spent fuel storage facilities or for new transport packaging designs are addressed sufficiently early. ASN also asked the industrial players to study the consequences, in terms of safety and radiation protection, of the implementation of the Multi-year Energy Plan (MEP) on the “nuclear fuel cycle” and its coherence, at each of its revisions. Following the MEP update published in April 2020, new energy mix scenarios were defined in July 2020 and, together with Framatome, Orano and Andra, EDF updated its management prospects for the “fuel cycle” in December 2020, in accordance with these energy mix scenarios. Saturation of spent fuel storage capacity could occur in 2030, or even 2029. In 2020, EDF also announced the postponement of the commissioning of its centralised storage pool project, now scheduled for 2034, which means that countermeasures are needed, in order to deal with the delay in this project: densification of the storage pools at La Hague, dry storage of spent fuels and greater use of MOX fuel in the reactors. 1.5 Outlook: planned facilities New uranium storage facility project on the Tricastin site In November 2017, Orano submitted a creation authorisation application for new buildings to store uranium-bearing materials resulting from fuel reprocessing. In 2018, ASN informed the Minister responsible for nuclear safety that the content of the creation authorisation application was sufficient for its examination DURING THE COURSE OF 2021, WORSENING OF THE PROBLEMS CONCERNING CERTAIN STEPS IN THE “FUEL CYCLE” The year 2021 revealed a worsening of the problems concerning certain steps in the “fuel cycle”: ཛྷ The Melox plant is still experiencing difficulties in producing MOX fuel of the required quality and quantity for the EDF fleet of reactors. These difficulties are leading to the production of a large quantity of radioactive materials containing plutonium qualified as “MOX scrap”, which is then stored in the La Hague plant, either in powder form, or in the form of fuel assemblies. ཛྷ An action plan has been implemented by Orano since 2019 to overcome the production difficulties at Melox. However, Orano indicates that the prospects for improvement and its MOX production forecasts are primarily based on the use of a “wet process” uranium powder, which should be produced as of 2023 in the new unit called the “New Wet Process” (NVH) in Orano’s Malvési plant, currently under construction. ཛྷ In the short term, problems at the Melox plant are also leading to faster than anticipated saturation of the storage capacity for plutonium-bearing materials, which requires the creation of new plutonium-bearing materials storage areas at La Hague. If storage capacity is not increased, reprocessing would have to be scaled down, which would then speed up congestion in the spent fuels storage pools. The authorisation application submitted by Orano for the creation of new plutoniumbearing materials storage areas at La Hague is currently being examined. ཛྷ A fission products evaporator-concentrator at La Hague was preventively shut down in September 2021 as it had reached a level of corrosion that precluded its continued operation. The shutdown of this evaporator, combined with an unscheduled maintenance shutdown of another evaporator in the same plant, led to a UP3-A plant outage of almost three months. These disruptions of the cycle back-end plants confirm the need identified by ASN in its opinion of 18 October 2018 for countermeasures, assuming that commissioning of the EDF centralised storage pool would occur after saturation of French spent fuel storage capacity. In September 2021, ASN called Orano to a hearing on these subjects. On this occasion, ASN asked Orano to reinforce its forward planning approach, notably by taking account of pessimistic scenarios regarding the Melox plant’s return to nominal operation, in order to define arrangements and storage solutions offering a high level of safety. 316 ASN Report on the state of nuclear safety and radiation protection in France in 2021 11 – “NUCLEAR FUEL CYCLE” INSTALLATIONS
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