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  • Author or Editor: N. Myasoedov x
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Abstract  

A kinetic study of hydrogen isotope exchange was carried out in a H2/Pd membrane/organic compound system for a number of compounds in the 0.2–20 kPa H2 pressure range. The results suggest a low specificity of the reaction kinetics for the compounds used. Possible reaction mechanisms are discussed and analyzed.

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Abstract  

The effect of agitation time and resin quantity on the sorption of americium, curium and europium from mineral acid solutions, using a chelating resin based on aminopolystyrene and Arsenazo I was determined, and the behaviour of plutonium and fission products was investigated under optimum conditions with respect to the sorption of americium and curium. A procedure is proposed for concentrating americium and curium from dilute solutions, combined with their separation from iron, plutonium and fission products. The procedure consists of sorption on the chelating resin from 0.1–1N mineral acid solutions, washing of the resin with 0.5M oxalic acid and 11N sulfuric acid, and elution of americium and curium with 2M triammonium citrate.

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Abstract  

A reaction mechanism is proposed for tritium labelling by the SCRD method /solid-state catalytic reductive dehalogenation/ based on hydrogen spillover. A model system /palladium membrane with a layer of the original organic compound/ is used for a kinetic study of the debromination of 5-bromouracil and the isotope exchange of -alanine at pressure of 0.07–20 kPa. A kinetic model is considered for the spillover stoppage due to the contamination of penetration centres by the reaction product. Other possible causes of the spillover stoppage are discussed.

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Abstract  

Extraction of actinides has been examined in two-phase aqueous systems based on poly(ethylene glycol) (PEG) from sulfate solutions in the presence of potassium phosphotungstate, which forms strong complexes with ions of tri- and tetravalent transuranium elements. Extraction of these complexes by aqueous PEG solution is complete in contrast to that of penta- and hexavalent actinides. Conditions have been chosen for the separation of actinides in different oxidation states.

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Abstract  

Extraction chromatographic behaviour of cesium, barium and strontium on TVEX impregnated by crown-ether dicyclohexyl-18-crown-6 was studied. Data obtained were used as the base of the technique of radiostrontium isolated from environmental objects.

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Abstract  

Extraction of trivalent lanthanides: La, Ce, Nd, Eu, Tb, Tm, Yb by primary high molecular weight amines from 0.5–3M hydrochloric acid solutions, containing complex-forming agent potassium phosphotungstate /K10P2W17O61/ has been investigated. The effect of hydrochloric acid, potassium phosphotungstate and amine concentration, the length of primary amine alkyl chain, organic solvents nature and elements ionic radii on distribution coefficients have been studied. It has been established that the system can be used for group isolation and separation of rare earth elements.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: N. Kremliakova, K. Barsukova, and B. Myasoedov

Abstract  

Behaviour of transplutonium and rare-earth elements on TVEX, containing TBP, HDEHP, mixture of TBPHDEHP (11), PAPNA and TOA has been studied. The analytical possibility of isolation and separation of tetravalent Pu and Bk from trivalent actinides and lanthanides from strong nitric acid solutions (1.0–12.0) on TVEX with TBP, POR, HDEHP and TOA has been demonstrated. The separation of trivalent Bk, Cf and Eu from Am and Cm is real on TVEX, containing HDEHP and mixture of TBPHDEHP.

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Abstract  

Extraction of trivalent rare earth elements by a high molecular weight primary amine /decylamine/ from 0.5–3M nitric acid solutions, containing potassium phosphotungstate /K10P2W17O61/, has been investigated. The effect of nitric acid and potassium phosphotungstate concentration of the organic solvent, and lanthanides ionic radii upon distribution coefficients has been studied. It has been established that decylamine solutions in chloroform can be used for the group isolation of rare earth elements and for their separation.

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Abstract  

Extraction of trivalent lanthanides and actinides by primary amines from nitric acid solution in presence of potassium phosphotungstate (K10P2W17O61) has been investigated. The effect of nitric acid, potassium phosphotungstate and extractant concentrations, of the organic solvents and the length of primary amine alkyl chain has been studied. Primary amines in chloroform can be used for separtion of lanthanides and actinides and their group isolation.

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Abstract  

The extraction chromatographic separation of Am/IV/ and Cm/III/ in the H2SO4-K10P2W17O61-Primene JMT system was studied. The elaborated method permitted to purify effectively americium. The yield of americium at an initial concentration of 10–3M is about 93–95%, the curium content does not exceed 0.1% of the initial concentration.

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