| Summary: | Resumen del trabajo presentado a la Radiation Protection Week, celebrada en Oxford (UK) del 19 al 23 de septiembre de 2016.-- et al. A major fraction of refractory radionuclides such as uranium (U) and plutonium (Pu) released to the environment from the nuclear weapon and fuel cycles is present as particles ranging from submicrons to fragments. Such particles can carry a substantial amount of radioactivity (e.g., fission and activation products, transuranics) and associated metals, and can act as point sources. Furthermore, U particles (progenies, metals) are ALSO present at NORM sites. Research indicates that particle characteristics such as composition, atom and element ratios depend on the emitting source, while particle size, structure and oxidation states are closely linked to the release scenarios. Following deposition, ecosystem transfer of particle associated radionuclides are delayed compared to mobile radionuclide species; i.e., ecosystem transfer would be delayed until particle weathering and remobilisation of associated radionuclides occur. The apparent soil-water distribution coefficient (Kd) will therefore change over time, and the thermodynamic constant concept should be replaced with rate functions. Thus, RATE project focuses on particle characteristics, weathering rates, remobilization and prediction of ecosystem transfer of radionuclides associated with U and/or Pu containing particles originating from selected key sources (nuclear weapons tests, safety tests, conventional detonation of nuclear or DU weapons, nuclear reactor accident, NORM). Utilizing advanced techniques, leaching experiments in which well characterized particles are exposed to abiotic and biotic degradation agents are being performed under different temperature conditions of relevance for the Arctic and for temperate zones. The parameterization should reduce uncertainties in model predictions on ecosystem transfer and environmental impact associated with particle contaminated areas, linking particle properties to sources, ...
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