Radionuclide sorption and desorption mechanisms in interbed/groundwater systems of the Columbia River basalt formation

Conference · Fri Oct 01 04:00:00 EDT 1982

OSTI ID:6670758

Barney, G S

The sorption and desorption mechanisms of key radionuclides (Tc, Np, Pu, Am, Cs, Sr, and Ra) in groundwater-interbed systems of the Columbia River basalt formation were investigated. Sandstone and tuff interbed materials from selected sedimentary interbeds were used in these experiments. The effects of groundwater composition and Eh on radionuclide sorption and desorption on the selected geologic solid were studied. Sodium, potassium, and calcium in the groundwater decrease sorption of Cs, Sr, and Ra by ion exchange reactions. Groundwater Eh strongly affects sorption of Tc, Np, Pu, and U since chemical species of these elements containing the lower oxidation states are more extensively sorbed by chemisorption. Effects of radionuclide complexation by groundwater anions on sorption were not observed except for neptunium carbonate (or bicarbonate) complexes and plutonium sulfate complexes. Sorption and desorption isotherms were obtained for sorption of key radionuclides under oxidizing and reducing conditions. The Freundlich equation accurately describes most of these isotherms. Most radionuclides are apparently irreversibly sorbed on each of the geologic solids since the slopes of sorption and desorption isotherms for a given radionuclide are different. This hysteresis effect is very large and will cause a significant delay in radionuclide transport. It, therefore, should be included in modeling radionuclide transport to accurately assess the isolation capabilities of a repository in basalt.

• Research Organization: Rockwell International Corp., Richland, WA (USA). Rockwell Hanford Operations
• DOE Contract Number: AC06-77RL01030
• OSTI ID: 6670758
• Report Number(s): RHO-BW-SA-276P; CONF-821053-1; ON: DE83002108
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
ADSORPTION
BASALT
CHEMISTRY
COLUMBIA RIVER BASIN
ENVIRONMENTAL TRANSPORT
GROUND WATER
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
ISOTOPES
MANAGEMENT
MASS TRANSFER
OXYGEN COMPOUNDS
RADIOACTIVE WASTE DISPOSAL
RADIOISOTOPES
RADIONUCLIDE MIGRATION
REDOX POTENTIAL
ROCKS
SORPTION
UNDERGROUND DISPOSAL
VOLCANIC ROCKS
WASTE DISPOSAL
WASTE MANAGEMENT
WATER
WATER CHEMISTRY