Geochemical controls on radionuclide releases from a nuclear waste repository in basalt: estimated solubilities for selected elements
Two basalt flows within the Grande Ronde formation at the Hanford Site in Southeastern Washington are candidates for a high-level nuclear waste repository. In order to determine the anticipated rates of release and migration of radionuclides from the repository, solubility controls must be determined for key elements. Solubilities, the solids controlling solubility and aqueous speciation for a variety of actinides and fission products in groundwater, have been determined at 25/sup 0/C from available thermodynamic data over a range of Eh values. Groundwater compositions used include all available analyses from the Grande Ronde formation determined by the Basalt Waste Isolation Project. Solids predicted to control solubility for the selected radionuclides include hydroxides and hydrous oxides (palladium, antimony, samarium, europium, lead, americium), oxides (nickel, tin, thorium, neptunium, plutonium), elements (selenium, palladium) and silicates (zirconium, uranium). Dominant soluble species include hydroxy complexes (zirconium, palladium, tin, antimony, samarium, europium, thorium, uranium, neptunium) and carbonate species (nickel, samarium, europium, lead, uranium, neptunium, plutonium, americium). The effect on solubility of dissolved, reduced (S/sup 2 -/, HS/sup -/) sulfur species is large for nickel, palladium, antimony, and lead. However, available data suggest that essentially all sulfur in Grande Ronde groundwater is in the form of sulfate (SO/sub 4//sup 2 -/). Selenium solubility appears to be a strong function of Eh and may reach very high levels where -0.45 > Eh > -0.05 V. This result suggests that future experimental work should include solubility determinations for selenium. In addition, other elements, notably technetium and radium, with large uncertainties in calculated solubility should also have solubilities determined experimentally.
- Research Organization:
- Atomics International Div., Richland, WA (USA). Rockwell Hanford Operations
- DOE Contract Number:
- AC06-77RL01030
- OSTI ID:
- 6068298
- Report Number(s):
- RHO-BW-ST-39P; ON: DE83013983
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
58 GEOSCIENCES
54 ENVIRONMENTAL SCIENCES
AMERICIUM
SOLUBILITY
ANTIMONY
EUROPIUM
GROUND WATER
RADIONUCLIDE MIGRATION
LEAD
NEPTUNIUM
NICKEL
PALLADIUM
PLUTONIUM
RADIOACTIVE WASTE DISPOSAL
GEOLOGIC DEPOSITS
SAMARIUM
SELENIUM
THORIUM
TIN
URANIUM
ZIRCONIUM
BASALT
DIFFUSION
EXPERIMENTAL DATA
HANFORD RESERVATION
REDOX POTENTIAL
ACTINIDES
DATA
ELEMENTS
ENVIRONMENTAL TRANSPORT
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
INFORMATION
MANAGEMENT
MASS TRANSFER
METALS
NATIONAL ORGANIZATIONS
NUMERICAL DATA
OXYGEN COMPOUNDS
PLATINUM METALS
RARE EARTHS
ROCKS
SEMIMETALS
TRANSITION ELEMENTS
TRANSPLUTONIUM ELEMENTS
TRANSURANIUM ELEMENTS
US DOE
US ERDA
US ORGANIZATIONS
VOLCANIC ROCKS
WASTE DISPOSAL
WASTE MANAGEMENT
WATER
053000* - Nuclear Fuels- Environmental Aspects
052002 - Nuclear Fuels- Waste Disposal & Storage
580400 - Geochemistry- (-1989)
520301 - Environment
Aquatic- Radioactive Materials Monitoring & Transport- Water- (1987)