INSTITUT DE PROTECTION ET DE SÛRETÉ NUCLÉAIRE IPSN To know booklets Radioecology and understand the evolution of radioactivity in the environment. The use of nuclear energy in both military and civil applications has led scientists to study the fate of radioactive products called "radionuclides" (see P. 21) released in the environment since the beginning of the 1940s. This concern has given birth to an ecological discipline - radioecology. Both natural and artificial radionuclides can be found throughout the environment. All you need to know about radioecology 1 What is radioecology? Radioecologists seek to understand the evolution of radionuclides in the environment and to collect data to predict their dosimetric impact. 2 Radioecology in the world and in France Studies on radioecology have been developed from 1940 up to the present day in parallel with military and civil nuclear activities. 3 Origins of radionuclides Weapons testing, accidents at facilities, controlled waste have released artificial radionuclides into the environment which are added to natural-occurring radionuclides. 4 Radioecology tools Measurements on samples taken in the field and laboratory work are the basis for development of software programmes used to predict dosimetric impact. 5 Marine radioecology Radioecologists carry out assessments on the effects of dumping waste from nuclear facilities at sea. 6 Radioecology of inland waters Liquid radioactive waste produced by nuclear facilities located along rivers is discharged into fresh water. 7 Land radioecology The radionuclides in the land ecosystem affect human health mainly through the food chain: plants animals meat or milk. 8 Radioecological studies in the field Around a nuclear power station - Radioactivity levels are regularly controlled in the different environments to measure the radioecological impact caused by waste from the power station. 9 Radioecological studies in the field The Nord-Cotentin Radioecology Group - In Nord-Cotentin, an inventory of radioactive waste from a fuel reprocessing plant was conducted. Mercantour workshop zone - In the Mercantour area, a "workshop zone" was created to trace the migration of the caesium-137 released in May 1986 after the Chernobyl accident. 10 A permanent observatory and instant information 1 11 What is radioecology? The purpose of radioecology is to detect the presence of radionuclides in the environment, to research their origins and to understand their process of transfer and their concentration in ecosystems. Its aim is to evaluate the impact of both natural and artificial radioactivity on the environment (radioecological impact) and on the population (dosimetric impact) (see P. 21). These studies are based on the same approach as those relating to other chemical polluting agents such as heavy metals (lead, zinc, etc.) or nitrates. Given the presence of radionuclides in all ecosystems and the complexity of the transfer processes, radioecologists work in three main environments in the biosphere: the marine aquatic environment, the inland aquatic environment and the land environment. From the picture … Air, land, water Radionuclides are scattered into the air and water, settle and living organisms, on the soil and sediments, migrate into the food chains … including human beings, make up and thus can affect man. the biosphere which can be subdivided into ecological units gas effluents called "ecosystems". A river, a lake, an ocean, a mountain chain, a tropical forest, a town or a desert liquid effluents are ecosystems. transfers breathing nutrition meat - milk - vegetables 2 … to the model … The environment can be depicted by a series of boxes through which radionuclides circulate. Radioecologists seek to measure the concentration of the radionuclides in each box and understand their transfer mechanisms. Wet and dry deposits Atmosphere Sediments Soils Drainage migration Deposits Irrigation Water Root transfers Plants Nutrition Animals … to predict the dosimetric impact Radioecology provides data used in calculating the dosimetric impact. Whether the waste be controlled or accidental, radioecology helps provide answers to potential questions from public authorities, the nuclear industry, the media or the public at large. 3 2 Radioecology in the world and in France The term "radioecology" first appeared in 1935 but only became widely used during the 1950s. It probably emerged from the combination of "radioactivity" and "ecology". The first radioecological work was published in Geneva in 1955 during the first international meeting on the use of nuclear energy in the Pacific. Significant events in the world … and in France 1940-1950 • First nuclear weapons tests • Divergence of ZOE reactor • Nuclear explosions at Hiroshima (Fontenay-aux-Roses - 1948) and Nagasaki ••••••••••••••••••• •••••••••••••••••••••••••••• 1950-1960 • Use of radionuclides in biology • Creation of an "ecology" group and agriculture at CEA • Kyshtym accident in the USSR • Beginning of scientific and at Windscale in Great Britain publications ••••••••••••••••••• •••••••••••••••••••••••••••• 1960-1970 • First international congress on • Creation of radioecological laboratories radioecology in the USA (1961) at CEA • Radioecology congress organised • First congress organised by Vienna Agency (IAEA – 1966) in France (Cadarache, 1969) ••••••••••••••••••• •••••••••••••••••••••••••••• 1970-1980 • Oil crisis, rise of nuclear energy • First reference states before • Accident at Three Mile Island installation of nuclear power in the USA stations (Bugey, Fessenheim) ••••••••••••••••••• •••••••••••••••••••••••••••• 1980-1990 • Accident at Chernobyl in Ukraine • Experimental studies (1986) on the effects of an accident on the environment: RESSAC programme (Cadarache) ••••••••••••••••••• •••••••••••••••••••••••••••• 1990-2001 • Development of studies • Study of the impact on the storage of radioactive waste of the Chernobyl accident (Vosges, Mercantour, Corsica) 4 The two main public bodies involved in the field of radioecology in France are IPSN and OPRI (Office de protection contre les rayonnements ionisants). IPSN carries out radioecological studies in the framework of its activities in research and assessment. Its department for the protection of the environment is organised around themes of study and has several sites. •Radioecological studies on the Atlantic seaboard La Hague Octeville •Experimental radioecology Le Vésinet Fontenay-aux-Roses Saclay Orsay •Modelling and validation of transfers Angers of radionuclides in the environment •Organisation of environmental data •Studies and intervention relating to radon and atmospheric contaminants Avignon Agen Cadarache • Inland radioecological studies and research on the Mediterranean Toulon Location of IPSN laboratories ( • ) Themes of the radioecological and OPRI agencies ( • ). studies developed at IPSN. OPRI is responsible for the supervision and regulatory control of radioactivity in the environment. It manages several warning networks which allow the authorities to react immediately should abnormal radioactivity levels be detected in France. 5 3 Origins of radionuclides Humans are continuously exposed to both natural and artificial radiation. Natural radioactivity Of the 340 different atoms (more precisely called "nuclides") found in nature, 70 are radioactive. These radionuclides (see P. 21) can be found throughout the environment … including in the human body. Sample Activity (roughly speaking) Predominant radionuclide Outside air between 1 and 100 Bq/m3 radon-222 Air inside houses between 10 and 10,000 Bq/m3 radon-222 Sedimentary land 1,000 Bq/kg uranium-238, thorium-232 and their daughter products, potassium-40 Granite 3,000 Bq/kg uranium-238, thorium-232 and their daughter products, potassium-40 Seawater 13 Bq/l potassium-40 Mineral water between 2 and 4 Bq/l potassium-40 Milk 80 Bq/l potassium-40 Potato 150 Bq/kg Humans 120 Bq/kg potassium-40 and carbon-14 Artificial radioactivity Of the more than 2,000 1. Atmospheric tests of nuclear weapons nuclear weapons tests At the time of the explosions, radionuclides (tritium, carried out throughout the world, 423 took place ruthenium-106, caesium-137, strontium-90…) were in the atmosphere propelled into the upper atmosphere and then settled on the between 1945 and 1981 (USA: 193, USSR: 142, continents and oceans in a relatively uniform manner. Over a France: 45, period of 35 years these atmospheric tests released a quantity Great Britain: 21, China: 22). of radionuclides equivalent to 500 times the waste from the Chernobyl accident. 6 Three accidents 2. Accidents at nuclear plants released significant When the Chernobyl accident occurred, radionuclides were quantities of radionuclides deposited over the entire European continent (iodine-131, into the environment: caesium-137, caesium-134, ruthenium-106 …). Windscale (Great Britain, 1957), Kyshtym (Russia, 1957) and Chernobyl (Ukraine, 1986). 3. Controlled nuclear industrial waste Nuclear facilities (nuclear power stations, fuel reprocessing plants) are authorised to release radionuclides into rivers or the sea (liquid effluents) or the air (gas effluents). Principal radionuclides… in liquid effluents in gas effluents Nuclear reactor tritium, cobalt-60, manganese-54 krypton-85, xenon-133, silver-110, antimony-124, iodine-131, iodine-131, tritium, caesium-137 carbon-14 Reprocessing plant tritium, caesium-137, ruthenium-106, tritium, krypton-85, strontium-90, antimony-125, iodine- xenon-133, iodine-129, 129, carbon-14 carbon-14 4. Fall