LES ACTIVITÉS NUCLÉAIRES : RAYONNEMENTS IONISANTS ET RISQUES POUR LA SANTÉ ET L’ENVIRONNEMENT Evaluation of radiation protection in facilities using cyclotrons ASNR has been exercising its oversight in this area since early 2010. Each new facility or any major modification of an existing facility undergoes an extensive examination by ASNR. The main radiation protection issues concerning these facilities must be considered as of the design stage. Application of the industrial standards, particularly standard NF M 62‑105 “Industrial accelerators: installations”, ISO 10648‑2 “Containment enclosures” and ISO 17873 “Ventilation systems for nuclear installations”, guarantees safe utilisation of the equipment and brings a significant reduction in risks. Facilities that have a cyclotron used to produce radionuclides and products containing radionuclides are subject to gaseous effluent discharge limits specified in their licence. The discharge levels depend on the frequency and types of production involved. Systems for filtering and trapping gaseous effluents are installed in the production enclosures and in the facilities’ ventilation systems in order to minimise the activity discharged at the stack outlet. An increasing number of licensees are also installing – as close as possible to the shielded enclosures – systems for collecting and storing the gases to let them decay before being discharged, bringing a substantial reduction in the activities discharged into the environment. These radioactive gas compression systems are then emptied after a decay time that is appropriate for the type of radionuclide. Consequently, the discharged activity levels and the short half-life of the radionuclides discharged in gaseous effluents mean there is no significant impact on the public or the environment. The work undertaken by ASN and IRSN over the last few years, and by ASNR since 2025, on the gaseous discharges into the environment from cyclotrons has clarified the regulatory requirements in this respect. New assessments of the impacts of discharges from the facilities situated near residential areas have been carried out using, for some facilities, modelling tools that are better suited to nearfield studies. Alongside this, IRSN acquired a computing tool in 2020 that provides a more accurate estimate of the radiological impacts by modelling the discharges in the immediate vicinity of the site concerned and performing, if necessary, counter-assessments of the studies provided by the licensees. In 2022, at the request of ASN, IRSN provided the cyclotron licensees with a document specifying the methodological steps for producing the radiological impact assessment of the atmospheric discharges from their facilities. This document details the different steps of an impact assessment, particularly the characterisation of the source term (discharges), a precise description of the local environment and of the transfers to the environment, emphasising the importance of the choice of dispersion calculation method and the final dose assessment. It is available on the ASNR website. In addition, ASN and IRSN worked jointly, with the participation of the cyclotron licensees, to clarify in particular the way atmospheric discharge limits are worded in the licences. At present, only the maximum dischargeable activity is usually indicated. The conclusions of this work will be an input for developing the future draft regulation relative to cyclotrons (see next page). ASNR performs about ten inspections at facilities of this type each year. Eight inspections were carried out in 2025. Of the eight sites inspected, three are primarily involved in research (using radionuclides produced for their own experiments and distributing them to third parties). Apart from the distribution of unsealed radioactive sources, the aspects relating to radiation protection, safety of use and the correct operation of cyclotrons and production platforms receive particular attention during the inspections. The scope of the inspections performed includes – apart from the topics relating to radiation protection – management of in-house abnormal events, the monitoring and maintenance of the production equipment, the inspection of the surveillance and control systems, the gaseous discharge results and management of the waste and liquid effluents. The supply of radiopharmaceuticals and radiochemicals is duly taken into account by the licensees. The organisation of radiation protection on all sites inspected is satisfactory. All the sites have appointed at least one RPE, and all have at least one CAMARI certificate holder. The exposed workers are trained and are all subject to appropriate dosimetric monitoring. All the companies have an equipment and radiation protection instrumentation verification programme that is established, except for two cases where the programme was incomplete and did not take full account of the applicable regulatory requirements under both the Labour Code and the Public Health Code. Similarly, checks and verifications of the presence and correct operation of safety and alarm devices for the cyclotron, shielded enclosures and containers containing radionuclides were carried out satisfactorily at most sites, except in two cases where the procedures for checking safety systems did not ensure that they were working properly (for example, it was possible to remove a captive key when the bunker door was open). Concerning the management of radioactive sources, the maximum activity of the radionuclides held complies with the licence conditions and appropriate measures are taken to prevent unauthorised access to the sources. The checks prior to final disposal of the contaminated waste and effluents are carried out and documented in all the inspected facilities. However, waste management remains a point requiring particular attention regarding the regular removal of the waste (to avoid cluttering the premises, especially on the oldest ones with cramped waste storage areas) that is to be recovered by Andra. The atmospheric Cyclotrons A cyclotron is a device 1.5 to 4 metres in diameter, belonging to the circular particle accelerator family. The accelerated particles are mainly protons, with energy levels of up to 70 MeV. A cyclotron consists of two circular electromagnets producing a magnetic field and between which there is an electrical field, allowing the rotation and acceleration of the particles at each revolution. The accelerated particles strike a target containing a liquid, gaseous or solid product which, once irradiated, will produce the desired radionuclide. Low and medium energy cyclotrons are primarily used in research and in the pharmaceutical industry to produce positron emitting isotopes, such as fluorine-18 or carbon-11. The radionuclides are then combined with molecules of varying complexity to form radiopharmaceuticals used in medical imaging. The best known of them is 18F-FDG (fluorodeoxyglucose marked by fluorine-18), which is an industrially manufactured injectable drug, commonly used for early diagnosis of certain cancers. Other radiopharmaceuticals manufactured from fluorine-18 have also been developed in recent years, such as 18F-Choline, 18F-Na, 18F-DOPA, as well as radiopharmaceuticals for exploring the brain. To a lesser extent, the other positron emitters that can be manufactured with a cyclotron of an equivalent energy range to that necessary for the production of fluorine-18 and carbon-11 are oxygen-15 and nitrogen-13. Their utilisation is however still limited due to their very short radioactive half-life. Some facilities are also starting to produce copper-64 or zirconium-89, which are still used today in research and clinical trials. The approximate levels of activities involved for the fluorine-18 usually found in pharmaceutical facilities vary from 30 to 1,000 GBq per production batch. The positron emitting radionuclides produced for research purposes involve activities that are usually limited to a few tens of gigabecquerels. HIGHLIGHT No. 12 ASNR Report on the state of nuclear safety and radiation protection in France in 2025 257 01 05 02 06 03 04 09 10 07 11 13 08 12 A / Z
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