Dissolution of UO{sub 2} (s) in MgCl{sub 2}-brines under different redox conditions

Conference · Thu Dec 30 23:00:00 EST 1993

OSTI ID:62192

Casas, I; Gimenez, J; De Pablo, J; Torrero, M E ^[1]

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1. Universitat Politecnica Catalunya, Barcelona (Spain)

The dissolution of unirradiated UO{sub 2} (s), with a particle size of 1 mm, has been studied in MgCl{sub 2} brines at 298 K under both reducing and oxidizing conditions. Results obtained under reducing conditions (h{sub 2} atmosphere in the presence of a palladium catalyst) show an initial increase of the total uranium concentration in solution and a subsequent decrease until equilibrium (or steady state) values are reached. Results obtained under oxidizing conditions (nominal oxygen partial pressures of 0.05, 0.21 and 1 atm) show two different trends. A relatively fast initial dissolution rate and, after approximately two or three weeks, a slower dissolution rate. X-ray Photoelectron Spectroscopy (XPS) has shown that the UO{sub 2} surface composition changes during the experiment.

• OSTI ID: 62192
• Report Number(s): CONF-921101--Vol.294
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
40 CHEMISTRY
BRINES
DISSOLUTION
MAGNESIUM CHLORIDES
RADIONUCLIDE MIGRATION
REDOX REACTIONS
SALT DEPOSITS
SPENT FUEL STORAGE
SPENT FUELS
UNDERGROUND DISPOSAL
URANIUM DIOXIDE