Objetivo The mobility and transfer of radionuclides in an ecosystem is highly dependent on the physico-chemical form of the deposited radioactivity. A unique characteristic of the radioactivity released during the Chernobyl accident was the presence of particles of irradiated uranium oxide fuel, called hot particles. In the vicinity of the reactor a large fraction of the deposited radionuclides was associated with fuel particles, and fall-out in this region contained enhanced levels of refractory radionuclides, actinides (Pu), and 90Sr. Thus, the long-term behaviour of radionuclides in this area will be influenced to a large degree by physico-chemical properties of fuel particles, rates of weathering, release and transformation processes. The main objective of this research study is to investigate the rates of release of radionuclides (i.e. 137Cs, 90Sr, Pu-isotopes, 241Am) from fuel particles and their transfer kinetics within the soil-water system. Characterisation of the size and properties of the fuel particle fraction of radionuclides in soils collected from the 30 km exclusion zone will be carried out using extraction techniques, autoradiography and alpha track analysis. The structure of isolated particles, before and after extraction, will be studied using electron microscopy. Kinetics of transformation processes will be determined by following the rate of release of radionuclides from fuel particles into soil solutions and other extractants over time. In addition, the rate of radionuclide adsorption by soils will be determined using both soil solutions containing radionuclides extracted from fuel particles and added radioactive tracers. The presence of colloidal forms of radionuclides in soil solutions will be investigated using ultrafiltration techniques. The influence of microbial activity, pH and temperature on transformation kinetics will also be studied. Information obtained from studies of 137CS and 90Sr will be augmented by analysis of naturally occurring Cs and Sr in soils. Radionuclide determination will be carried out using gamma, beta and alpha spectrometry and actinides (Pu, Am will be determined using ICP-MS). Results are expected to provide comprehensive data on the environmental effect of fuel particles in the event of a reactor accident; the studies carried out will provide data on the physico-chemical composition of fuel particles, including oxidation states of particles (i.e. UO2, UO3, U3O8), actinide levels (Pu and Am), kinetic parameters of transformation processes, the influence of soil parameters on particle weathering rates, and the future mobilisation of radionuclides, especially Sr-90 and actinides, from particles to run-off water and vegetation. Programa(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Tema(s) 58 - Environmental Monitoring and Modelling Convocatoria de propuestas Data not available Régimen de financiación Data not available Coordinador Agricultural University of Norway Aportación de la UE Sin datos Dirección 1432 Aas Noruega Ver en el mapa Coste total Sin datos Participantes (3) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo Scientific Production Association Typhoon Rusia Aportación de la UE Sin datos Dirección 249020 Obninsk - Kaluga Region Ver en el mapa Coste total Sin datos Ukrainian Institute of Agricultural Radiology Ucrania Aportación de la UE Sin datos Dirección 255205 Chabany - Kiev Region Ver en el mapa Coste total Sin datos University of Manchester Reino Unido Aportación de la UE Sin datos Dirección Oxford Road M13 9PL Manchester Ver en el mapa Coste total Sin datos
