Annual Activity Report 2025

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RISK CONTROL AND VIGILANCE PLAN Vigilance plan

All these rules ensure the safe and responsible management of radioactive waste within the group and the development of consistent and ef fi cient practices across all its sites. Orano is involved in researching new waste treatment processes as well as sharing experiences to improve and optimize waste management. Information on waste flows and volumes stored at Orano’s nuclear facilities, particularly volumes, is communicated to the relevant authorities in the form of annual reports. Application of the French National Plan for the Management of Radioactive Materials and Waste (PNGMDR) The sustainable radioactive waste management solutions used by Orano align with the guidelines of the French National Plan for the Management of Radioactive Materials and Waste (PNGMDR). The PNGMDR assesses existing management methods for radioactive materials and waste, identi fi es the anticipated needs for storage or disposal facilities, and speci fi es the required capacities for these facilities and their storage durations. Its development and updates – extended from three to fi ve years in the fi fth edition (2022-2026) – are carried out under the supervision of the French Nuclear Safety Authority (ASNR) and Directorate General for Energy and Climate (DGEC). Orano is strongly involved in the development of the PNGMDR, and is represented by its Strategic Decommissioning and Waste Programming Department, which leads and coordinates cross functional actions and studies related to the plan’s development, implementation, and monitoring. The internal governance of the PNGMDR has been strengthened since 2020 with the establishment, within Orano, of the strategic and technical committee (STC). The STC is responsible for validating and deploying the action plans for the implementation of the PNGMDR. The STC meets quarterly but additional thematic meetings may be organized as needed. Prevention of the risk of a nuclear accident The occurrence of a nuclear accident at a facility may result in an uncontrolled release of radioactive substances with potential consequences for the environment around the group’s facilities. Risk prevention To avoid this risk, Orano makes nuclear safety a permanent priority and deploys rigorous preventive measures to ensure the safety of its facilities and the operations carried out there under all circumstances. The compliance of the measures taken, and their application are regularly checked by the competent authorities and, in France, by inspectors from the French nuclear safety authority (ASNR), the Regional Directorates of Environment, Land settlement and Housing (DREAL), and the High Defense and Security Of fi cer (HFDS). Principle of defense in depth Within the group, nuclear safety is ensured through a comprehensive set of technical, organizational and human measures covering the design, construction, operation, shutdown occurring at a facility Description of the risk

and decommissioning of regulated nuclear facilities, as well as the transport of radioactive substances, taken to prevent accidents and limit their effects. The prevention of nuclear risks is based on the principle of defense in depth, consisting of a succession of risk management measures (“lines of defense”) aimed at mitigating technical or human failures: ● the fi rst level of defense in depth is incident prevention. It consists of equipping the facility, from the design phase, with strong intrinsic resilience during operation and decommissioning, both against its own failures and against prede fi ned external hazards. It also relies on speci fi c attention to the construction phase; ● the second level is monitoring. It enables the detection of incidents, the implementation of actions to prevent them from leading to an accident, and the restoration of normal operation or the return of the facility to a safe state; ● the third level is mitigation of consequences. It allows control of accidental situations that could not be prevented or, failing that, their aggravation to be limited by bringing the facility back to and maintaining it in a safe state; and ● fi nally, the purpose of the fourth level is to manage the most severe accidents to mitigate the consequences of accidents resulting from the failure of the third level of defense in depth. These four levels of defense are supplemented by a fi fth level which includes organizational measures and resources for emergency management and public protection as part of a continuous improvement approach. In addition to the measures implemented to prevent the risks of an incident or accident and limit, to the greatest possible extent, their consequences on sites and the surrounding environment, sites in possession of nuclear materials must take measures to prevent the loss, theft or diversion of the materials held in the facilities, or any act that might result in their dispersal of material in the environment. As with nuclear safety, the measures taken are based on the principle of “defense in depth”, which consists of putting in place successive barriers. Safety studies for facilities Safety studies are carried out for each facility. The safety studies carried out for each facility take into consideration internal risks of nuclear (criticality, radiolysis, etc .) and non-nuclear origin (chemicals, handling, fi re, etc .) from the design stage, as well as external risks (tornado, earthquake, etc .). The risks are reassessed every 10 years during the periodic review of each nuclear facility. These reviews, which are a regulatory obligation for regulated nuclear facilities (INB), enable a regular reassessment of the level of safety of an installation taking into account the latest regulatory changes and the best available techniques. In practice, they may lead to material modi fi cations to the facilities. The purpose of this exercise is to obtain the necessary approvals from the competent safety authority to continue operating a facility for the next 10 years. Subject to ASNR approval, each fi le is also sent to the competent Minister. As in previous years, 2025 saw sustained activity in terms of periodic reviews, with investigations in progress on several sites.

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Orano - Annual Activity Report 2025