Longterm leaching of natural radionuclides from uranium mill tailings material: comparison of indoor and outdoor column experiments
-
W. Schimmack
The leaching of natural radionuclides from the material of a uranium mill tailing at Crossen/Saxony was investigated using eight columns (20 cm diameter, 50 cm height). Six columns were irrigated in the laboratory by synthetic rainwater of pH 6, 3 and 2, two columns were exposed outdoor to natural meteorological conditions. In the effluent of the columns, the concentrations of the radionuclides were measured periodically. With exception of the initial phase after installation of the columns (ca. 0.4 y), the leaching rates of radionuclides decreased slowly within the observation period of 4.5 years. Due to the buffering capacity of the tailings material, acidifying the irrigation water of the laboratory columns did not effect the effluent concentrations of the radionuclides. However, significant differences were observed between laboratory and outdoor columns: outdoor, the concentration of 235U in the effluents was for the first two years substantially smaller than in the laboratory. As a consequence, the accumulated leached activity of 235U during 4.5 years was 19.0±0.9% of the inventory for the laboratory columns, but only 10.9±0.6% for the outdoor columns. While uranium thus proved to be rather soluble, the concentration of 226Ra in the effluents was quite small (<1 Bq/l). Thorium was retained completely in the columns.
© 2015 Oldenbourg Wissenschaftsverlag GmbH, Rosenheimer Str. 145, 81671 München
Artikel in diesem Heft
- Formation of americium(III) complexes with aqueous silicic acid
- The reduction of plutonium and neptunium ions by acetaldoxime in nitric acid
- Complex formation of U(VI) with Bacillus-isolates from a uranium mining waste pile
- Longterm leaching of natural radionuclides from uranium mill tailings material: comparison of indoor and outdoor column experiments
- Enrichment analysis of uranium in uranium oxide by gamma-ray spectrometry without using calibration standards
- Gas phase chemistry of technetium and rhenium oxychlorides
- Synthesis and chromatographic characterization of [Tc-99m]technetium-humic acid species
- Retention of some hazardous radionuclides from nitric acid solution using tin(IV) antimonate as a cation exchanger
- Study of adsorption of zinc ions on hydrous zirconium oxide surface
- Radiometric analysis of the spent fuel pool water and reactor coolant of ET-RR.1
- Separation of carrier-free cerium radionuclides from different target matrix produced by heavy ion beams
Artikel in diesem Heft
- Formation of americium(III) complexes with aqueous silicic acid
- The reduction of plutonium and neptunium ions by acetaldoxime in nitric acid
- Complex formation of U(VI) with Bacillus-isolates from a uranium mining waste pile
- Longterm leaching of natural radionuclides from uranium mill tailings material: comparison of indoor and outdoor column experiments
- Enrichment analysis of uranium in uranium oxide by gamma-ray spectrometry without using calibration standards
- Gas phase chemistry of technetium and rhenium oxychlorides
- Synthesis and chromatographic characterization of [Tc-99m]technetium-humic acid species
- Retention of some hazardous radionuclides from nitric acid solution using tin(IV) antimonate as a cation exchanger
- Study of adsorption of zinc ions on hydrous zirconium oxide surface
- Radiometric analysis of the spent fuel pool water and reactor coolant of ET-RR.1
- Separation of carrier-free cerium radionuclides from different target matrix produced by heavy ion beams
