The commissioning of three new cyclotrons is scheduled for the years 2023 and 2024. The assessment of radiation protection in facilities using cyclotrons ASN 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 ASN. The main radiation protection issues concerning these facilities must be considered as of the design stage. Application of the standards, in particular standard NF M 62-105 “Industrial accelerators: installations”, ISO 10648-2 “Containment enclosures” and ISO 17873 “Ventilation systems for nuclear installations”, guarantees safe use of the equipment and 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 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. Some licensees have also installed – 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. Consequently, the discharged activity levels and the short halflife of the radionuclides discharged in gaseous effluents mean there is no significant impact on the public or the environment. The work that began in 2016, with IRSN support, on the gaseous discharges from the cyclotrons resulted in 2018 in a doctrine, of which the key principles, will be used to draft a regulatory text. Alongside this, 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. As a complement, 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. During 2022, ASN and IRSN explored jointly, with the participation of the cyclotron licensees, options 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. Nine sites were inspected in 2022, including one where the inspection targeted a new reprocessing plant for water both enriched with oxygen-18 (used in the pharmaceutical production process) and contaminated more particularly with tritium during the cyclotron irradiation phases. 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 aspects 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. In the eight radiopharmaceutical production facilities, the organisation of radiation protection is satisfactory since at least one person holding the CAMARI certificate is appointed, except on one site where the RPA’s training was not up to date. The exposed workers are trained and are all subject to appropriate dose monitoring. With the exception of two sites, the periodic verifications, including the presence and correct functioning of the safety and alarm devices and maintenance operations, are carried out exhaustively. Lastly, in all the inspected facilities the waste and contaminated effluents are properly managed and checked before disposal or discharge. Lastly, national action plans are put into place by the licensees of the two major French radiopharmaceutical production groups and are monitored annually by ASN to ensure continuous improvement of radiation protection and safety in these facilities. Six ESR were reported by the cyclotron licensees in 2022. None of these events led to significant exposure of workers or the public. Three ESR were related to delivery errors (two involved the delivery of an activity exceeding the customer’s maximum authorised activity, while the third concerned the delivery a day early when the customer had not placed an order for that day). Two other events concerned in one case the contamination (with no radiological consequences) of the face of a female operator who was splashed with micro-droplets when handling a pipette of fluorine-18, and in the other, exceeding by a few gigabecquerels the maximum activity handled in an enclosure. Lastly, one facility reported one exceedance its annual limit for discharges of radioactive gaseous effluents. Further verifications of both the measurements and the calculations established that the discharges were actually below the authorised maximum value. This event had led to an incident notice published on the ASN website and was rated level 1 on the International Nuclear and Radiological Event Scale (INES). 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 will continue in 2023 in order to create a single regulatory baseline for the whole sector. 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. ASN Report on the state of nuclear safety and radiation protection in France in 2022 261 08 • 08 • Sources of ionising radiation and their industrial, veterinary and research applications 01 07 13 AP 04 10 06 12 14 03 09 05 11 02
RkJQdWJsaXNoZXIy NjQ0NzU=