ASN Report 2018

Some applications necessitate the use of beams of photons or electrons produced by particle accelerators. The French pool of particle accelerators, whether linear (linacs) or circular (synchrotrons), comprises about 60 listed installations (excluding cyclotrons – see point 4.2 – and excluding BNIs), totalling slightly over one hundred accelerators, which can be used in highly diverse areas, such as: ∙ ∙ research, which sometimes requires the coupling of several machines (accelerator, implanter, etc.); ∙ ∙ radiography (fixed or mobile accelerator); ∙ ∙ radioscopy of lorries and containers during customs checks (fixed-site or mobile accelerators); ∙ ∙ modification of material properties; ∙ ∙ sterilisation; ∙ ∙ conservation of foodstuffs; ∙ ∙ … In the field of research, two synchrotron radiation production facilities can be mentioned in France: the ESRF (European Synchrotron Radiation Facility) in Grenoble, and the Soleil (Optimised source of energy light) synchrotron in Gif-sur-Yvette. Particle accelerators have been used for a few years now in France to fight fraud and large-scale international trafficking. This technology, which the operators consider effective, must however be used under certain conditions in order to comply with the radiation protection rules applicable to workers and the public, in particular: ∙ ∙ A ban on activation of construction products, consumer goods and foodstuffs as specified by Article R. 1333-2 of the Public Health Code, by ensuring that the maximum energy of the particles emitted by the accelerators used excludes any risk of activation of the materials being verified. ∙ ∙ A ban on the use of ionising radiation on the human body for purposes other than medical. ∙ ∙ The setting up of procedures to ensure that the checks conducted on the goods or transport vehicles do not lead to accidental exposure of workers or other individuals. The use of ionising technologies to seek out illegal immigrants in transport vehicles is thus prohibited in France. During customs inspections of trucks using scanner technologies, for example, the drivers must be kept away from the vehicle and other checks must be performed prior to irradiation to detect the presence of any illegal immigrants in order to avoid unjustified exposure of people during the inspection. Distribution of particle accelerators by end-use 0 5 10 15 20 25 Neutron analysis Surface treatment (including polymer cross-linking) Sterilisation Logging Ion implantation Veterinary radiotherapy Other Measuring instrument calibration Design of accelerators for commercialisation Security inspection Non-destructive inspection Scientific research Number of licencees 1 1 2 3 3 3 3 3 3 4 11 23 Graph 10 Synchrotrons The synchrotron is a member of the same family of circular particle accelerators as the cyclotron (see point 4.2), but is far larger, enabling energies of several gigaelectronvolts to be achieved by means of successive accelerations. Owing to the low mass of the particles (generally electrons), the acceleration created by the curvature of their trajectory in a storage ring produces an electromagnetic wave when the speeds achieved become relativistic: this is synchrotron radiation. This radiation is collected at various locations called beam lines and is used to conduct scientific experiments. 248  ASN report on the state of nuclear safety and radiation protection in France in 2018 08 – SOURCES OF IONISING RADIATION AND THEIR INDUSTRIAL, VETERINARY AND RESEARCH APPLICATIONS