ASN Report 2018

4 —  Manufacturers and distributors of radioactive sources and their oversight by ASN 4.1  ̶  The issues and implications The aim of ASN oversight of the suppliers of radioactive sources or devices containing them is to ensure the radiation protection of the future users. It is based on the technical examination of the devices and sources with respect to operating safety and radiation protection conditions during future utilisation and maintenance. It also allows the tracking of source transfers and the recovery and disposal of disused or end-of-life sources. Source suppliers also play a teaching role with respect to users. At present, only the suppliers of sealed radioactive sources or devices containing them, and of unsealed radioactive sources, are regulated in France (see point 2.3.1). There are about 150 suppliers of sources with significant business, and among them, 33 low and medium-energy cyclotrons that are currently licensed under the Public Health Code in France. 4.2  ̶  Cyclotrons • Functioning As at 31 December 2018, 30 cyclotrons were in operation. Among these, 17 are used exclusively for the daily production of radiopharmaceuticals, 6 are used for research purposes and 7 are used for joint production and research purposes. • The assessment of radiation protection in the area of cyclotrons ASN has exercised its oversight role in this area since early 2010; each new facility or any major modification to an existing facility is the subject of a complete examination by ASN. The main radiation protection issues on these facilities must be considered as of the design stage. Application of 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. The 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 the 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. As a result of the activity discharged and the short half-life of the radionuclides discharged in gaseous effluents,there is no significant impact on the public or the environment. ASN, jointly with IRSN, is continuing a study they began in 2016 on the gaseous discharges into the environment from these facilities. The conclusions of the first work which involved both IRSN and the licensees, served to establish general principles on gaseous effluent discharges in 2018, the salient points of which will be taken up in a draft regulatory text (see below). This work will continue in 2019 with updated assessments of the impact of discharges from facilities situated near residential areas. 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 electric field, allowing the rotation of the particles and their acceleration at each revolution. The accelerated particles strike a target which is activated and produces radionuclides. 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 18 F-FDG (fluorodeoxyglucose marked by fluorine-18), which is an industrially manufactured injectable drug, commonly used for early diagnosis of certain cancers. Other radiopharmaceutical drugs manufactured from fluorine-18 have also been developed in recent years, such as 18 F-Choline, 18 F-Na, 18 F-DOPA, along with other 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 half-life. The approximate levels of activities involved for the fluorine-18 usually found in pharmaceutical facilities vary from 30 to 500 GBq per production batch. The positron emitting radionuclides produced for research purposes involve activities that are usually limited to a few tens of GBq. ASN report on the state of nuclear safety and radiation protection in France in 2018  251 08 – SOURCES OF IONISING RADIATION AND THEIR INDUSTRIAL, VETERINARY AND RESEARCH APPLICATIONS 08