effluent discharge limits specified in their license. 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 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 near-field 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 study 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 ASN and IRSN websites. 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). ASN performs about ten inspections at facilities of this type each year. Eight inspections were carried out in 2024. Of the eight sites inspected, three have transfer lines between the cyclotron and an industrial player (research laboratories). 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 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 the eight sites inspected is satisfactory. All the sites have appointed at least one RPE, and in just one case the RPE’s training certificate was not up to date, but the situation was being rectified. All the inspected sites have at least one person who holds the CAMARI certificate. The exposed workers are trained and are all subject to appropriate dose monitoring. All the companies have an equipment and radiation protection instrumentation verification programme that is established, except for one case where certain instrumentation calibration verifications had not been carried out. Likewise, the inspections and verifications of the presence and correct functioning of the cyclotron safety and alarm devices, of the shielded enclosures and of the recipients containing radionuclides are carried out on all the sites. 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. Atmospheric discharges are generally well monitored. It was this monitoring that led to the rapid detection of discharges beyond authorized limits mentioned in the paragraph on ESRs. Lastly, national action plans are put into place by the licensees of the two major French radiopharmaceutical production groups and are reviewed annually by ASN to ensure continuous improvement of radiation protection and safety in these facilities. Four ESRs were reported by the cyclotron licensees in 2024. None of these events led to significant exposure of workers or the public. Two of the reported events involved a slight exceedance of the authorised limit for radioactive atmospheric discharges, detected further to a metrological problem with the measuring probes. Measures have been taken to limit the discharges, such as early replacement of the charcoal filters and the installation of storage tanks to allow radioactive decay of gases before discharge, as well as measures to enhance measurement reliability, particularly the installation of screens around the measurement probes to reduce spurious radiation. The first of the other two ESRs concerns the delivery of radiopharmaceuticals that did not comply with the activity authorised by the client’s license. The second event concerns the triggering of a worker’s active dosimeter alarm after opening a shielded enclosure when a synthesis was in progress, due to a failure of the enclosure locking system. There are disparities in the technical and organisational means implemented by the licensees, depending on the age of the facilities and the type of activities performed (research or industrial production). Experience feedback in this area has led ASN, assisted by IRSN, to draw up a draft resolution on the technical design and operating rules applicable to facilities producing radionuclides using a cyclotron and on the control and monitoring of their gaseous effluent discharges. The draft resolution has already undergone several informal consultations with the stakeholders and discussions with the DGT; its preparation is continuing in order to create a single regulatory baseline for the whole sector concerned. The main conclusions of this regulatory work are already being used when examining license applications for these facilities in order to include appropriate requirements in the individual licenses. The conclusions resulting from the considerations on the wording of the atmospheric discharge limit values will also be included. 272 ASN Report on the state of nuclear safety and radiation protection in France in 2024 Sources of ionising radiation and their industrial, veterinary and research applications
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