ASN Report 2017

148 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 04  - Regulation of nuclear activities and exposure to ionising radiation These monitoring principles are supplemented in the individual requirements applicable to the facilities by monitoring measures specific to the risks inherent in the industrial processes they use. Each year, in addition to sending ASN the monitoring results required by the regulations, the licensees transmit nearly 120,000 measurements to the national network for environmental radioactivity monitoring. 4.2.3 Environmental monitoring nationwide by IRSN IRSN’s nationwide environmental monitoring is carried out by means of measurement and sampling networks dedicated to: ཛྷ ཛྷ air monitoring (aerosols, rainwater, ambient gamma activity); ཛྷ ཛྷ monitoring of surface water (watercourses) and groundwater (aquifers); ཛྷ ཛྷ monitoring of the human food chain (milk, cereals, fish, etc.); ཛྷ ཛྷ terrestrial continental monitoring (reference stations located far from all industrial facilities). This monitoring is based on: ཛྷ ཛྷ continuous on-site monitoring using independent systems (remote-monitoring networks) providing real-time transmission of results. This includes: -- the Téléray network (ambient gamma radioactivity in the air) which uses a system of continuous measurement monitors around the whole country. The density of this network is being increased around nuclear sites within a radius of 10 to 30 km around BNIs; -- the Hydrotéléray network (monitoring of the main watercourses downstream of all nuclear facilities and before they cross national boundaries); -- continuous sampling networks with laboratory measurement, for example the atmospheric aerosols radioactivity monitoring network; ཛྷ ཛྷ processing and measurement in a laboratory of samples taken from the various compartments of the environment, whether or not close to facilities liable to discharge radionuclides. Every year, IRSN takes more than 25,000 samples in all compartments of the environment (excluding the remote- measurement networks). The radioactivity levels measured in France are stable and situated at very low levels, generally at the detection sensitivity threshold of the measuring instruments. The artificial radioactivity detected in the environment results essentially from fallout from the atmospheric tests of nuclear weapons carried out in the 1960s, and from the Chernobyl accident. Traces of artificial radioactivity associated with discharges can sometimes be detected near installations. To this can be added very local contaminations resulting from incidents or past industrial activities, and which do not represent a health risk. On the basis of the nationwide radioactivity monitoring results and in accordance with the provisions of ASN resolution 2008- DC-0099 of 29th April 2008, as amended, IRSN regularly publishes a report on the radioactive state of the French environment. The first issue of this report, published at the beginning of 2013, covered the year 2010 and the first half FOCUS Detection of traces of ruthenium-106 in the ambient air in September and October  2017 During the course of its national radioactivity monitoring duties, IRSN measured the presence of very low levels (a few microbecquerels per cubic metre) of ruthenium-106 in the ambient air in the South-East of France, between the end of September and the beginning of October 2017. As soon as this was detected, ASN contacted its European counterparts, who confirmed the detection of ruthenium-106 in the air over the same period in at least 14 European countries, with the highest values being measured in the countries of Eastern Europe. The end of this episode was confirmed as of the second half of October 2017. As ruthenium-106 is not normally detected in the air, ASN considered that its presence could only be linked to an uncontrolled release, probably as a result of an accident. However, at the time this report was written no country had informed the IAEA that it is the origin of this release, as required by the 1986 convention on the early notification of a nuclear accident. IRSN carried out simulations to recreate the release from the measurement results observed in France and Europe. It compared its results with those of other expert assessment organisations in Europe, such as BFs (Germany), STUK (Finland) and NRPA (Norway). On the basis of these simulations, IRSN determined that the most probable origin of this release was the southern Urals, without it being possible to be any more precise. The event causing this release probably occurred during the course of the final days of September. The levels of atmospheric contamination by ruthenium-106 which were observed in France and the other European countries have no consequences for health and the environment and thus required no measures to protect the populations. ASN also examined the risk linked to the consumption of imported foodstuffs. The estimated radiological doses linked to the consumption of foodstuffs from the probable area in which the release originated, mushrooms in particular, showed that there was no identified health risk for consumers in France. Following the invitation sent by IBRAE (Russian scientific committee), ENSREG, via its Chairman, jointly with the European Commission and together with the Russian safety regulator Rostechnadzor and IBRAE, determined the conditions for the participation in an international scientific commission tasked with determining the origin and circumstances of this release, as well as its local impact.