A new method for determining oxygen solubility in molten carbonates and carbonate-chloride mixtures using the oxidation of UO2 to uranate reaction / Volkovich VA,Griffiths TR,Fray DJ,Thied RC // JOURNAL OF NUCLEAR MATERIALS. - 2000. - V. 282, l. 2-3. - P. 152-158.

ISSN/EISSN:

0022-3115 / нет данных

Type:

Article

Abstract:

One of the possible pyrochemical reprocessing procedures for spent ceramic nuclear fuels may involve the oxidation of UO2 in alkali metal carbonate and carbonate-based melts, and this is controlled by the level of dissolved oxygen in the melt. A quantitative relationship has been derived between the extent of UO2 oxidation and the concentration of oxygen (peroxide/superoxide) species formed upon oxygen dissolution in carbonates. A novel sensitive method for determining oxygen solubility in molten carbonates and carbonate-based melts has thus been developed. The concentrations of the alkali metal uranates(VI) formed can then be accurately determined without interference from unreacted UO2. Oxygen solubilities at temperatures from 450 degreesC to 800 degreesC have been determined. The solubility of oxygen in a range of carbonate-chloride melts was also determined and found to increase with decreasing radius of the cation of the alkali metal chloride added. Measurements at various partial pressures of oxygen allowed the determination of the predominant oxygen species formed in the melt, and preliminary experiments showed that in the ternary carbonate melt, at 450 degreesC, oxygen dissolves forming mainly superoxide ions. The applicability of Henry's Law in this situation is examined. (C) 2000 Elsevier Science B.V. All rights reserved.

Author keywords:

ELECTRODE REACTION; AU-ELECTRODES; QUANTITATIVE-ANALYSIS; REDUCTION; KINETICS; MELTS; LI2CO3-K2CO3; CURVES; POWDER

DOI:

10.1016/S0022-3115(00)00427-X

Web of Science ID:

ISI:000166025300008

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	DEC
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	ELECTRODE REACTION; AU-ELECTRODES; QUANTITATIVE-ANALYSIS; REDUCTION; KINETICS; MELTS; LI2CO3-K2CO3; CURVES; POWDER
Research-Areas	Materials Science; Nuclear Science \& Technology
Web-of-Science-Categories	Materials Science, Multidisciplinary; Nuclear Science \& Technology
ResearcherID-Numbers	Volkovich, Vladimir/K-8339-2012
ORCID-Numbers	Volkovich, Vladimir/0000-0003-4438-1194
Number-of-Cited-References	28
Usage-Count-Since-2013	12
Journal-ISO	J. Nucl. Mater.
Doc-Delivery-Number	385VJ