[en] Results of recent work devoted to the cementation of liquid radioactive wastes are summarized. Attention is paid to volume reduction of the wastes prior to the solidification and to the chemical stability of the cementation products. A brief comparison is made of cementation with other solidification processes. (Z.M.). 1 fig., 1 tab., 41 refs

[en] The most interesting papers are discussed dealing with methods of separation of compunds formed in radiochemical determinations. Attention is focused on extraction, separation with the use of precipitates and isotope exchange. Radioimmunoassay and radioreceptor methods are compared. A more detailed analysis is made of the work of Soviet scientist Shamaev in the field of radioanalytical methods. (E.S.). 52 refs., 2 tabs., 1 fig

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No abstract available

[en] A survey is presented of the procedures of cementing liquid radioactive wastes from nuclear power plants developed in the world, such as lead to a reduction in the volume of stored products. The conclusion is arrived at that the main method of reducing the volume of radioactive wastes is evaporation while the use of filtration or sedimentation is rare. The most frequently designed installation for the evaporation of liquid radioactive wastes is the film rotor evaporator. The economic effects of the designed procedures are significant, in some instances cementation may provide a smaller final volume of stored radioactive wastes than bituminization. (Z.M.). 2 tabs., 39 refs

[en] The measurement of activity of ⁹⁰Sr during its fast isolation by extraction with cobalt dicarbollide and Slovafol 909 in a nitrobenzene-carbon tetrachloride mixed solvent and re-extraction with 0.15 M Chelaton IV at pH 10.2 was investigated. The use of a liquid scintillator allows the effect of the ⁹⁰Y beta activity to be eliminated more efficiently than if the evaporation residue is measured with a solid scintillator. Traces of dicarbollide, nitrobenzene and CCl₄ passed into the aqueous solution exert an unfavorable effect by shifting the spectral curve of the ⁹⁰Sr+⁹⁰Y beta radiation towards lower energies, the shift being dependent on the concentration of the above interferents in the aqueous phase. This effect can be eliminated by extracting the aqueous phase with the same volume of octyl alcohol or amyl acetate; while removing the organic interferents, this extraction brings about no apparent loss of strontium. (author). 3 tabs., 7 figs., 5 refs

[en] The results are summarized of recent research and development efforts in radioactive waste cementation. The conclusions show that the cementation of waste oils and other organic solutions is now competitive with the process of their combustion. The feasibility was also confirmed of using normal cement, and the advantage was shown of ash, slug, tuff type rock and other additions. It was shown that within certain limits, the grain size of powders added to cement can play a bigger role than the chemical nature of the cement. On the other hand, the question of whether it is possible to effectively prepare cement products with a technically significant borate content remains controversial. (Z.M.). 33 refs

[en] A survey of the existing methods of treating radioactive sludges is presented with reference to previous publications. (J.B.). 26 figs., 34 refs

[en] The fluoride reprocessing of fast reactor fuels, the separation of selected valuable and biological emitters from radioactive wastes, and the problems of zirconium and uranium hydrometallurgy are discussed. The flow chart of the process uranium branch for spent fuel reprocessing for reactor BOR-60, developed by UJV in co-operation with Soviet institutions consists of several operations, viz., the removal of the stainless steel fuel element cladding by melting, the oxidation of UO₂ to U₃O₈, fluorination and condensation, the separation of Pu from uranium, distillation purification of UF₆, sorption-desorption purification of UF₆, waste gas treatment. The development is described of the two-stage phosphate process of radioactive waste treatment (stage one: denitration and calcination, stage two:melting). (H.S.)

[en] To achieve a good separation of strontium from barium and radium, the conditions of reextraction of this element were examined. Attention was paid to the duration of extraction, to sodium and lithium ion concentrations and pH of the equilibrium phase. The strontium and barium concentrations were determined by means of ⁸⁵Sr and ¹³³Ba tracers. The Ba-Sr separation factor approached 10⁴ for the system studied. (J.B.). 4 tabs., 6 figs., 7 refs