This volume provides a comprehensive overview on the chemical thermodynamics of those elements that are of particular importance in the safety assessment of radioactive waste disposal systems. This is the first volume in a series of critical reviews to be published on this subject. The book provides an extensive compilation of chemical thermodynamic data for uranium. A description of procedures for activity corrections and uncertainty estimates is given. A critical discussion of data needed for nuclear waste management assessments, including areas where significant gaps of knowledge exist is presented. A detailed inventory of chemical thermodynamic data for inorganic compounds and complexes of uranium is listed. Data and their uncertainty limits are recommended for 74 aqueous complexes and 199 solid and 31 gaseous compounds containing uranium, and on 52 aqueous and 17 solid auxiliary species containing no uranium. The data are internally consistent and compatible with the CODATA Key Values. The book contains a detailed discussion of procedures used for activity factor corrections in aqueous solution, as well as including methods for making uncertainty estimates.

The Chemistry of the Actinide and Transactinide Elements is a contemporary and definitive compilation of chemical properties of all of the actinide elements, especially of the technologically important elements uranium and plutonium, as well as the transactinide elements. In addition to the comprehensive treatment of the chemical properties of each element, ion, and compound from atomic number 89 (actinium) through to 109 (meitnerium), this multi-volume work has specialized and definitive chapters on electronic theory, optical and laser fluorescence spectroscopy, X-ray absorption spectroscopy, organoactinide chemistry, thermodynamics, magnetic properties, the metals, coordination chemistry, separations, and trace analysis. Several chapters deal with environmental science, safe handling, and biological interactions of the actinide elements. The Editors invited teams of authors, who are active practitioners and recognized experts in their specialty, to write each chapter and have endeavoured to provide a balanced and insightful treatment of these fascinating elements at the frontier of the periodic table. Because the field has expanded with new spectroscopic techniques and environmental focus, the work encompasses five volumes, each of which groups chapters on related topics. All chapters represent the current state of research in the chemistry of these elements and related fields.

The present volume Uranium C12 covers the binary and polynary carbides of uranium, including ternary carbides with nonmetals like the carbide oxides and carbide nitrides U(C,O) and U(C,N). The binary carbide UC and especially the mixed carbide (UO.80PUO.20)C are of special importance due to their potential as the fuel for advanced .. Fast Breeder Reactors" because of properties such as the short doubling time, the high fissionable material density, and the good thermal conductivity. On the other hand, the dicarbide UC is of interest for .. High 2 Temperature Reactors", especially in the form of the mixed carbide (U . Th . )C . For O80 o20 2 the first time, India used mixed uranium-plutonium carbide (U . PU .)C as the fuel for its O3 O7 own newly developed 15 MW Fast Breeder Reactor at Kalpakkam, south of Madras. el Because of the technological importance of the uranium carbides a lot of data were published only in reports. In most cases, it was the aim of these less-scientifically based studies to promote the carbide fuel development on an economical basis. The lack of analyti cal data on the purity of the samples, missing characterization of the present phases, etc., hQINever, does not allow the discussion of the results of such references in this handbook. Therefore, only reliable publications were cited. For the technical fabrication of uranium carbides and their irradiation behavior, see Volumes A3 and A4 of this Handbook.

During the last decade there has been a renewed interest in under standing from a fundamental point of view the gasification of carbon. Basi cally there are two major issues in controlling the reactivity of carbon: i) reduction of the gasification rate of carbon materials in hostile environment ii) increase of the gasification rate in order to utilize carbonaceous compounds more effectively. Although these two objectives look somewhat contradictory, they are part of the general topics of understanding gasification reactivity of carbon. Refractory applications of carbon in furnace linings, seals and vanes, as well as the use of carbon-carbon or carbon-ceramic composites in struc tures able to withstand corrosion at high temperature require a better understanding of the fundamentals involved in carbon-oxidizing gas (02' CO , H 0) reactions. Furthermore a great interest of aluminium producers 2 2 is 10 extending the lifetime of carbon electrodes in alumina electrolysis which primarily depends on reducing their consumption rates by air or carbon dioxide. Proper control of gasification reactions is also of prime importance in manufacturing carbonaceous adsorbents like granular activated carbon clothes of high adsorption characteristics. The balance between increase of porosity and decrease in mechanical strength during activation is critical for developing new porous types of carbon materials in particular for carbon clothes and this can only be achieved by a careful control of the gasification reaction.