Filters
Results 1 - 1 of 1
Results 1 - 1 of 1.
Search took: 0.021 seconds
AbstractAbstract
[en] This study concerns the development of the new concept for the decontamination of plutonium bearing solid wastes, based on the lixiviation of the wastes using electro-generated reducing agents. First, a comparative study of the kinetics of the dissolution of pure PuO2 (prepared by calcination of Pu (IV) oxalate at 450 C) in sulfuric acid media, with different reducing agents, was realized. Qualitatively these reagents can be sorted in three groups: 1 / fast kinetics for Cr(II), V(II) and U(III); 2 / slow kinetics for Ti(III); 3 / very slow kinetics for V(III) and U(VI). In order to contribute to the design of an electrochemical reactor for the generation of the reducing agents usable for the lixiviation of plutonium bearing solid wastes, the study of the diffusion coefficients of both oxidized and reduced forms of different redox couples, at different temperatures, was undertaken. The results of this study also permits, from the knowledge of the diffusional activation energy of the ions, to conclude that the dissolution of pure plutonium dioxide under the action of these reducing agents is not diffusion limited. The feasibility of the plutonium decontamination treatment of synthetic or real solid wastes was then studied at laboratory scale using electro-generated V(II), which is with Cr(II) among the best reagents. The efficiency of the treatment was good, (80 pc Pu solubilisation yield), especially in the case of cellulosic or miscellaneous organic wastes. (author)
[fr]
L'interet industriel de la dissolution des oxydes d'actinides en general, et notamment de PuO2 seul ou contenu dans les dechets justifie cette etude. Une etude comparee des cinetiques de dissolution d'un meme lot de PuO2 par differents reducteurs est realisee, a plusieurs temperatures en milieu sulfurique. De maniere empirique les reducteurs sont classes en trois groupes: Cr(II), V(II) et U(III) dissolvent rapidement PuO2, Ti(III) plus lentement que les precedents, V(III) et U(IV) sont les moins efficaces. La mesure chronopotentiometrique, a diverses temperatures, des coefficients de diffusion de la forme oxydee et reduite des couples redox mis en jeu permet d'estimer l'energie d'activation de diffusion de chaque espece electroactive. Il ressort qu'en aucun cas la diffusion n'est l'etape limitante pour la dissolution. La possibilite d'un traitement de dechets synthetiques et reels contamines en PuO2 par V(II) electrogenere in situ est testee a l'echelle du laboratoire. Dans le cas des cendres d'incineration et des dechets organiques broyes, respectivement 32 pc et 80 pc du PuO2 sont dissous. La generation electrolytique des reducteurs, notamment V(II), sur electrode d'or amalgame est egalement decrite. (auteur)Original Title
Lixiviation de dechets solides plutoniferes par des solutions de reducteurs electrogeneres
Primary Subject
Secondary Subject
Source
20 Dec 1991; 134 p; 54 refs.; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS website for current contact and E-mail addresses: http://www.iaea.org/inis/contacts/; These Docteur de l'Universite Paris 6, Specialite: chimie analytique
Record Type
Report
Literature Type
Thesis/Dissertation
Report Number
Country of publication
ACTINIDE COMPOUNDS, CHALCOGENIDES, CHEMICAL REACTIONS, CHEMISTRY, CLEANING, DISSOLUTION, HYDROGEN COMPOUNDS, INORGANIC ACIDS, INORGANIC COMPOUNDS, KINETICS, MANAGEMENT, OXIDES, OXYGEN COMPOUNDS, PLUTONIUM COMPOUNDS, PLUTONIUM OXIDES, PROCESSING, RADIOACTIVE WASTE MANAGEMENT, REACTION KINETICS, REPROCESSING, SEPARATION PROCESSES, SULFUR COMPOUNDS, TRANSURANIUM COMPOUNDS, WASTE MANAGEMENT, WASTE PROCESSING, YIELDS
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue