Matrix for immobilization of radioactive technetium

Лаверов, Н. П.; Yudintsev, S. V.; Konovalov, E. E.; Mishevets, T. O.; Никонов, Б. С.; Omel’yanenko, B. I.

doi:10.1134/s0012500810030031

Cited by 6 publications

(3 citation statements)

References 4 publications

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“…Theirs structure is built of murataite and pyrochlore modules, and they accumulate more than 95% of the total amount of actinides [1,3,5]. The central parts of grains of the "murataite" phases are formed by the phase with the fivefold fluorite cell and maximal concentration of the actinide.…”

Section: Resultsmentioning

confidence: 99%

“…The uncertainty in measuring the electron binding energies and line widths is ±0.1 eV, and in measuring the relative intensities, ±10%. The full widths at half-maximum Г (eV) for these lines are given (Table 1) relative to Г(C1s) = 1.3 eV, so as to make the data comparable with those of the other studies [3].…”

mentioning

confidence: 93%

“…Conclusions on the oxidation state of actinides can be made both from the binding energies of inner electrons and from the characteristics of the fine structure of their XPE spectra [2]. Previously we studied by XPES borosilicate glasses with U [3] and pyrochlore ceramics containing Се and Th [4]. In this study, we examined by this method the surface of a ceramic of the elemental composition TiMn-Ca-An-Zr-Al-Fe-O with the murataite structure, containing actinides (An = Th, U, Np, and Pu), with the aim to determine the oxidation state of actinides and changes in the elemental composition of the surface compared to the bulk.…”

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confidence: 98%

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X-ray photoelectron study of murataite ceramics containing Th, U, Np, and Pu

Maslakov

Teterin

et al. 2012

Radiochemistry

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The structure of X-ray photoelectron spectra of actinide-containing (An = Th, U, Np, and Pu) murataite ceramic (Ti-Mn-Ca-An-Zr-Al-Fe-O) samples as potential matrices for immobilization of actinide radioactive waste was studied. The elemental composition of the sample surface was analyzed, and comparison with the calculated data for the bulk of the samples was made. The binding energies of the An4f electrons and the parameters of the fine structure of their X-ray photoelectron spectra were determined. These parameters were compared with the corresponding values for the dioxides.The environmentally safest way of high-level waste (HLW) isolation is their vitrification or ceramization followed by disposal in geological repositories. For HLW immobilization, it is suggested to use aluminum phosphate and borosilicate glasses [1]. Unfortunately, they crystallize with time, which leads to an increase in their solubility in water. To decrease the volume and enhance the reliability of HLW storage, it is appropriate to perform partitioning with the separation of actinide elements, which are the most long-lived and radiotoxic. Correspondingly, it is necessary to incorporate the actinide fraction into a special ceramic based on chemically stable and radiation-resistant phases. The development of stable matrices for actinide waste immobilization is an important scientific and practical problem. Therefore, it is an urgent problem to reveal phases with high capacity for actinides and other HLW components, to determine the oxidation state and coordination of radionuclide cations in them, and to analyze the stability of the structure of phases on the surface of the ceramic matrix [1].To understand processes that occur in matrices in storage, it is necessary to know the physicochemical forms (ionic composition, oxidation state of elements, structure of the nearest surrounding) of radionuclides in them. X-ray photoelectron spectroscopy (XPES) allows studying the chemical state of elements on the surface of ceramic matrices. Conclusions on the oxidation state of actinides can be made both from the binding energies of inner electrons and from the characteristics of the fine structure of their XPE spectra [2]. Previously we studied by XPES borosilicate glasses with U [3] and pyrochlore ceramics containing Се and Th [4]. In this study, we examined by this method the surface of a ceramic of the elemental composition TiMn-Ca-An-Zr-Al-Fe-O with the murataite structure, containing actinides (An = Th, U, Np, and Pu), with the aim to determine the oxidation state of actinides and changes in the elemental composition of the surface compared to the bulk. This is necessary for predicting the stability of such ceramic in prolonged storage.

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Section: Resultsmentioning

confidence: 99%

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confidence: 93%

mentioning

confidence: 98%

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X-ray photoelectron study of murataite ceramics containing Th, U, Np, and Pu

Maslakov

Teterin

et al. 2012

Radiochemistry

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Activated carbon additives for technetium immobilization in bentonite-based engineered barriers for radioactive waste repositories

Makarov

Safonov

Konevnik

et al. 2021

Journal of Hazardous Materials

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Incorporating technetium in minerals and other solids: A review

Luksic

Riley

Schweiger

et al. 2015

Journal of Nuclear Materials

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Technetium (Tc) can be incorporated into a number of different solids including spinel, sodalite, rutile, tin dioxide, pyrochlore, perovskite, goethite, layered double hydroxides, cements, and alloys. Synthetic routes are possible for each of these phases, ranging from high-temperature ceramic sintering to ball-milling of constituent oxides. However, in practice, Tc has only been incorporated into solid materials by a limited number of the possible syntheses. A review of the diverse ways in which Tc-immobilizing materials can be made shows the wide range of options available. Special consideration is given to hypothetical application to the Hanford Tank Waste and Vitrification Plant, such as adding a Tc-bearing mineral to waste glass melter feed. A full survey of solid Tc waste forms, the common synthesis routes to those waste forms, and their potential for application to vitrification processes are presented. The use of tin dioxide or ferrite spinel precursors to reduce Tc(VII) out of solution and into a durable form are shown to be of especially high potential.

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Matrix for immobilization of radioactive technetium

Cited by 6 publications

References 4 publications

X-ray photoelectron study of murataite ceramics containing Th, U, Np, and Pu

X-ray photoelectron study of murataite ceramics containing Th, U, Np, and Pu

Activated carbon additives for technetium immobilization in bentonite-based engineered barriers for radioactive waste repositories

Incorporating technetium in minerals and other solids: A review

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