sup 234 U/ sup 238 U and sup 230 Th/ sup 234 U activity ratios in the collidal phases of aquifers in lateritic weathered zones

Journal Article · Tue Nov 01 00:00:00 EST 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90026-9· OSTI ID:7068867

Short, S A; Lowson, R T ^[1]; Ellis, J ^[2]

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1. Lucas Heights Research Labs., Menai (Australia)
2. Univ. of Wollongong (Australia)

A procedure was developed for comparing solute and colloid phases of groundwaters in contact with uranium ore bodies at Nabarlek and Koongarra in the Alligator Rivers region, Northern Territory, Australia. Single-pass ultrafiltration of large volumes with cut-offs of 18 nm and 1 {mu}m was used. Colloids were composed of Fe and Si species with sorbed U and U daughters. Uranium isotopes were mostly present as soluble species. Thorium was significantly associated with the colloids. The {sup 234}U/{sup 238}U activity ratios (ARs) were similar in solute and colloid phases close to the ore bodies but further down-gradient colloids were generally more depleted of {sup 234}U than the solute. The {sup 230}Th/{sup 234}U ARs rose from very low values for both solute and colloid phases close to the ore bodies through several orders of magnitude to much higher values further down-gradient. Colloid {sup 230}Th/{sup 234}U ARs were always significantly greater than solute ARs. Results were consistent with a systematic leaching of U from colloids going down-gradient and very little mobilization of ore body. {sup 230}Th relative to U. Ubiquitous complexes {sup 232}Th appeared to suppress the solubility of {sup 230}Th.

• OSTI ID: 7068867
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 52:11; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
GROUND WATER
ISOTOPE RATIO
QUANTITATIVE CHEMICAL ANALYSIS
RADIONUCLIDE MIGRATION
NORTHERN TERRITORY
URANIUM ORES
LEACHING
WEATHERING
AQUIFERS
COLLOIDS
GEOCHEMISTRY
KOONGARRA DEPOSIT
NABARLEK DEPOSIT
SOLUBILITY
SOLUTES
THORIUM 230
URANIUM 234
URANIUM 238
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
AUSTRALASIA
AUSTRALIA
CHEMICAL ANALYSIS
CHEMISTRY
DISPERSIONS
DISSOLUTION
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
GEOLOGIC DEPOSITS
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
HYDROGEN COMPOUNDS
ISOTOPES
MAGNESIUM 28 DECAY RADIOISOTOPES
MASS TRANSFER
MINERAL RESOURCES
NEON 24 DECAY RADIOISOTOPES
NUCLEI
ORES
OXYGEN COMPOUNDS
RADIOISOTOPES
RESOURCES
SEPARATION PROCESSES
THORIUM ISOTOPES
URANIUM DEPOSITS
URANIUM ISOTOPES
WATER
YEARS LIVING RADIOISOTOPES
540330* - Environment
Aquatic- Radioactive Materials Monitoring & Transport- (1990-)
050100 - Nuclear Fuels- Reserves
Exploration
& Mining