The results of electronic structure modeling of plutonium and americium higher oxide molecules (actinide oxidation states VI through VIII) by two-component relativistic density functional theory are presented. Ground-state equilibrium molecular structures, main features of charge distributions, and energetics of AnO3, AnO4, An2On (An=Pu, Am), and PuAmOn, n = 6-8, are determined. In all cases, m...

The group separation of trivalent actinides and lanthanides and the mutual separation of americium and curium are necessary for the transmutation of americium. We have proposed the separation system based on the chromatography using the tertiary pyridine-type resin. In this separation system, the complete separation method of the trivalent actinides and lanthanides are already established using...

Abstract A method for rapid separation of americium from complex matrices by use two commercially available extraction chromatography resins is reported. TRU resin capable purifying americium/lanthanides together Group 1, 2 and transition metals. tolerated high loadings iron, aluminium, calcium sodium potassium. TEVA purified elution with ammonium thiocyanate. Decontamination factors > 20,00...

The biogeochemical behaviour of americium in subsurface soils plays a dominant role on its potential migration, but is currently poorly known. This research investigates the relevant processes controlling americium biogeochemical speciation in the rhizosphere of an agricultural soil. Lixiviation tests were performed on columns packed with a calcareous soil contaminated with Am, under steady-sta...

A novel approach for the Raman measurement of nuclear materials is reported in this paper. It consists of the enclosure of the radioactive sample in a tight capsule that isolates the material from the atmosphere. The capsule can optionally be filled with a chosen gas pressurized up to 20 bars. The micro-Raman measurement is performed through an optical-grade quartz window. This technique permit...

The results of investigations of transuranic elements { H , , M 0 P u and 2 4 'Am) behaviour in the soil-vegetation cover of natural and semi-natural ecosystems in the regions of Belarus contaminated as a result of Chernobyl acci­ dent have been summarised. The parameters of plutonium and americium vertical migration have been estimated for typical soil varieties; the radionuclides accumulation...

A biokinetic model of the systemic distribution of americium in the beagle dog is presented. The model is based on a previous biokinetic model of plutonium. The data sets used for the development of the model are the measurements of excreted activity (urine and feces) and organ burdens (skeleton, liver and other soft tissues). In developing the model, the part of the plutonium model representin...

Radioactive particles from three locations were investigated for elemental composition, oxidation states of matrix elements, and origin. Instrumental techniques applied to the task were scanning electron microscopy, X-ray and gamma-ray spectrometry, secondary ion mass spectrometry, and synchrotron radiation based microanalytical techniques comprising X-ray fluorescence spectrometry, X-ray fluor...

The aim of this work is to present the method for sequential plutonium and americium activity determination in air filters using chromatographic radionuclide separation and alpha spectrometry measurement. The developed method may be employed for the purposes of workplace monitoring and as an indicator of the need of introducing the individual monitoring as well as a useful complementation of in...