Diffusion of (226)Ra and (40)K radionuclides reproduced in underwater sedimentary columns in laboratory.
The potential radiological impact of the increase of radioactive substances in the environment makes interesting the study of the migration of the contaminant radionuclides in soils and sediments, which are the last receiver system of these substances. By using a battery of sedimentary columns controlled in the laboratory, the diffusion of the (226)Ra and (40)K radionuclides has been studied, assessing their respective effective diffusion coefficients in a similar sedimentary medium. A decreasing temporal evolution is obtained, associated to the progressive 'fixation' of the radionuclides by the clay minerals of the sediment, followed by a constant tendency. A timescale of the 'fixation' by the sediment is determined, being of the order of days for (226)Ra and of the order of months for (40)K, so the progressive 'fixation' of (40)K by the clay minerals of the sediments is slower than in the case of (226)Ra.
Departamento de Física Aplicada, CASEM, Universidad de Cádiz, Campus Rio San Pedro, 11510 Puerto Real, Cádiz, Spain. rufino.ligero@uca.es
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Feria
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Casas-Ruiz
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D000538:Aluminum Silicates / Q000032:analysis; D000077215:Clay; D004058:Diffusion; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D007753:Laboratories; D008903:Minerals / Q000032:analysis; D011197:Potassium Radioisotopes / Q000032:analysis*; D011883:Radium / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D012995:Solubility; D013997:Time Factors; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D000538:Aluminum Silicates; D008903:Minerals; D011197:Potassium Radioisotopes; D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive; D000077215:Clay; D011883:Radium