Uranium fixation during uranium migration under an oxidizing condition

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

OSTI ID:382903

Murakami, Takashi; Tsuzuki, Katsuyuki ^[1]; Sato, Tsutomu; Isobe, Hiroshi; Ohnuki, Toshihiko ^[2]

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1. Ehime Univ., Matsuyama, Ehime (Japan)
2. Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

A rock specimen, collected downstream of the Koongarra uranium ore deposit, Australia, was examined mainly by high resolution transmission electron microscopy in order to understand the uranium fixation mechanism. Uranium was found to exist as saleeite (Mg(UO{sub 2}){sub 2}(PO{sub 4}){sub 2}.10H{sub 2}O) microcrystals of 1--20 nm scattered between iron minerals (mainly goethite and hematite) of 2--50 nm. The microtextural relationship between saleeite and the iron minerals revealed that the iron minerals function as catalyst for the formation of saleeite. The intermediate metamict microstructures of the saleeite microcrystals are consistent with the estimated formation age of saleeite, 1 to 3 {times} 10{sup 6} years. Uranium has been, thus, fixed as saleeite downstream as well as in the secondary ore deposit. Saleeite in the secondary ore deposit showed completely periodic to fully metamict microstructures, suggesting that saleeite, a major uranium mineral in the secondary ore deposit, probably began to form a few million years ago and continued to form for the next million years.

• OSTI ID: 382903
• 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
ACTINIDES
AUSTRALIA
HIGH-LEVEL RADIOACTIVE WASTES
MINERALOGY
ORIGIN
PERFORMANCE
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE FACILITIES
RADIONUCLIDE MIGRATION
ROCK-FLUID INTERACTIONS
SALEEITE
SORPTION
URANINITES
URANIUM
URANIUM DEPOSITS
URANYL PHOSPHATES
URANYL SILICATES