Oxidation of ceramic uranium dioxide in alkali metal carbonate-based melts: a study using various oxidants and comparison with UO2 powder / Volkovich VA,Griffiths TR,Fray DJ,Fields M // JOURNAL OF NUCLEAR MATERIALS. - 1998. - V. 256, l. 2-3. - P. 131-138.

ISSN/EISSN:

0022-3115 / нет данных

Type:

Article

Abstract:

The oxidation of broken sintered ceramic UO2 pellets has been studied between 723 and 1073 K in a range of carbonate-based melts and under a variety of oxidising conditions. Comparison with the oxidation of UO2 powder under corresponding conditions showed that the reactivity of these media with ceramic UO2 was less, due to a lower relative surface area and a lower chemical activity of the sintered material. Pure carbonate melts, and with added alkali metal chlorides, produced essentially no reaction with ceramic UO2, Bubbling the melt with air or oxygen for many hours also had little effect. Addition of nitrate enabled the rate and extent of the reaction to be controlled, by varying the concentration of the oxidising agent and keeping the nitrate-to-UO2 mole ratio below similar to 0.4. Above this ratio the available surface area was the main controlling factor of the reaction. Controlled in situ generation of superoxide ions increased significantly the uranate yield at 723 K. A minimum concentration of oxidising agent is thus necessary before reaction commences. Complete oxidation of ceramic UO2 was achieved in similar to 2 h at 873 K in carbonate melts that contained KNO3 and were bubbled with oxygen. (C) 1998 Elsevier Science B.V. All rights reserved.

Author keywords:

OXYGEN; URANATE; SOLUBILITIES; MIXTURES; LITHIUM

DOI:

10.1016/S0022-3115(98)00065-8

Web of Science ID:

ISI:000075494200007

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	AUG
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	OXYGEN; URANATE; SOLUBILITIES; MIXTURES; LITHIUM
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	25
Usage-Count-Since-2013	2
Journal-ISO	J. Nucl. Mater.
Doc-Delivery-Number	112KQ