ASN Report 2017

51 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 01  - Nuclear activities: ionising radiation and health and environmental risks For waters displaying high radioactivity, the annual effective dose resulting from daily consumption (2 litres/inhabitant/day) may reach several tens or hundreds of microsieverts (µSv). 2.1.2 Radon Some geological areas have a high radon exhalation potential due to the geological characteristics of the ground (granitic bedrock, for example). The concentration measured inside homes also depends on the tightness of the building (foundations) and the ventilation of the rooms. So-called “domestic” exposure to radon (radon in dwellings) has been estimated by IRSN throughmeasurement campaigns which were then followed by statistical analyses (see www.irsn.fr) . The average radon activity value measured in France is 63 Bq/m 3 , with about half the results being below 50 Bq/m 3 , 9% above 200 Bq/m 3 and 2.3% above 400 Bq/m 3 . These measurements have allowed the French départements to be classified according to the radon exhalation potential of the ground (see map below). In 2011, IRSN published a new map of France considering the radon exhalation potential of the ground, based on data from the French Geological and Mining Research Office (BRGM). A finer classification per municipality will be based on this and will be available in 2018. Ultimately, the new obligation placed on dosimetry laboratories to communicate the dosimeter results to IRSN should enhance knowledge of radon exposure in France (see the 3rd National Plan for Radon Risk Management, published in January 2017 and accessible on www.asn.fr) . 2.1.3 Cosmic radiation The cosmic radiation from ionic and neutronic components is also accompanied by electromagnetic radiation. At sea level, the dose rate resulting from electromagnetic radiation is estimated at 32 nSv per hour and that resulting from the neutronic component at 3.6 nSv per hour. Considering the average time spent inside the home (which itself attenuates the ionic component of cosmic radiation), the average individual effective dose in a locality at sea level in France is 0.27 mSv per year, whereas it could exceed 1.1 mSv per year in a mountain locality situated at an elevation of about 2,800 metres. The average annual effective dose per individual in France is 0.32 mSv. It is lower than the global average value of 0.38 mSv per year published by UNSCEAR. On account of the increased exposure to cosmic radiation due to extensive periods spent at high altitude, flight personnel must be subject to dosimetric monitoring (see point 3.1.3). 2.2 Ionising radiation arising from human activities The human activities involving a risk of exposure to ionising radiation, called nuclear activities, can be grouped into the following categories: ཛྷ ཛྷ operation of BNIs; ཛྷ ཛྷ transport of radioactive substances; ཛྷ ཛྷ small-scale nuclear activities; ཛྷ ཛྷ disposal of radioactive waste; ཛྷ ཛྷ management of contaminated sites; ཛྷ ཛྷ activities enhancing natural ionising radiation. 2.2.1 Basic Nuclear Installations Regulations classify nuclear facilities, called Basic Nuclear Installations (BNI), in various categories corresponding to more or less restrictive procedures, depending on the significance of the potential risks (see chapter 3, point 3). The main BNI categories are: ཛྷ ཛྷ nuclear reactors; ཛྷ ཛྷ some particle accelerators; ཛྷ ཛྷ the plants that prepare, enrich or transform radioactive substances, particularly nuclear fuel production plants, irradiated fuel processing plants, and the facilities for processing and storing the radioactive waste produced by these plants; ཛྷ ཛྷ the installations intended for the processing, disposal, storage or use of radioactive substances, including waste, when the quantities involved exceed thresholds set by regulations. The list of BNIs as at 31st December 2017 figures in an appendix to this report. Accident prevention and nuclear safety The fundamental internationally adopted principle underpinning the specific organisational system and regulations applicable to nuclear safety is that of the responsibility of the licensee (see chapter 2). The public authorities ensure that this responsibility is fully assumed, in compliance with the regulatory requirements. As regards the prevention of risks for workers, BNI licensees are required to implement all necessary means to protect workers against the hazards of ionising radiation. They must more particularly ensure compliance with the general rules applicable to all workers exposed to ionising radiation (work organisation, accident prevention, medical monitoring of workers, including those from outside contractors, etc.) (see chapter 3). Thomas Pesquet, astronaut.