Modelling study on uranium migration in rocks under weathering condition

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:382904

Ohnuki, Toshihiko; Isobe, Hiroshi; Sato, Tsutomu; Yanase, Nobuyuki ^[1]; Murakami, Takashi ^[2]

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1. Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Dept. of Environmental Safety Research
2. Ehime Univ., Matsuyama, Ehime (Japan). Dept. of Earth Sciences

A modelling study has been completed to understand the effect of rock alteration on uranium migration at the Koongarra ore deposit, Australia. The model considers the weathering process, the mechanism and rate of chlorite alteration, a major mineral of the host rock, and assumes the presence of reversible sorption sites of chlorite and the presence of reversible and irreversible sorption sites of the weathering products. One- and two-dimensional, calculated uranium concentrations were compared with those observed. Good agreement between the calculated and observed uranium concentration profiles was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of Fe-minerals produced during weathering of chlorite. On the other hand, the conventional Kd model failed to estimate an adequate uranium concentration profile. The results suggest that the fixation of uranium to Fe-minerals has dominated the migration of uranium in the vicinity of the Koongarra ore deposit.

• OSTI ID: 382904
• Report Number(s): CONF-941075--; ISBN 1-55899-253-7
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
54 ENVIRONMENTAL SCIENCES
AUSTRALIA
CHLORITE MINERALS
FLOW MODELS
GEOLOGIC MODELS
GROUND WATER
IRON COMPOUNDS
PERFORMANCE
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE FACILITIES
RADIOECOLOGICAL CONCENTRATION
RADIONUCLIDE MIGRATION
ROCK-FLUID INTERACTIONS
SIMULATION
SORPTIVE PROPERTIES
URANIUM
URANIUM DEPOSITS
WEATHERING