OXIDATION OF UO2 IN MOLTEN ALKALI-METAL CARBONATE MIXTURES - FORMATION OF URANATES AND DIURANATES

Authors
VOLKOVICH V GRIFFITHS TR FRAY DJ FIELDS M WILSON PD
Citation
V. Volkovich et al., OXIDATION OF UO2 IN MOLTEN ALKALI-METAL CARBONATE MIXTURES - FORMATION OF URANATES AND DIURANATES, Journal of the Chemical Society. Faraday transactions, 92(24), 1996, pp. 5059-5065
Citations number
38
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Journal title
Journal of the Chemical Society. Faraday transactions → ACNP
ISSN journal
09565000
Volume
92
Issue
24
Year of publication
1996
Pages
5059 - 5065
Database
ISI
SICI code
0956-5000(1996)92:24<5059:OOUIMA>2.0.ZU;2-#
Abstract
The oxidation of UO2 in a variety of alkali-metal carbonate melts has been studied in the temperature range 723-1123 K. UO3 reacts with carb onate in the presence of oxygen to produce a mixture of mono- and di-u ranates. The monouranate is favoured at high temperature. In the prese nce of alkali-metal nitrate salts the reaction rate is increased marke dly: 100% oxidation of UO, is possible at 723 K in 1 h. Oxygen stirrin g of the melt also increases the rate of oxidation over air stirring a nd simple stirring. The mechanism of oxidation of UO2 is dependent upo n generation of peroxide and superoxide ions in the carbonate melt.