[en] Three sodium aluminophosphate glasses proposed for the immobilization of high- and medium-level radioactive wastes were studied by IR and ESR spectroscopy. This study involves the effect of Cs₂O, SrO, CoO, CaO, Fe₂O₃, SO₃, and NaCl on the anionic motic of the glasses. It is shown that the structural network of sodium aluminophosphate glasses consists of interlinked [PO₄] and [AlO₄] groups. The addition of Cs₂O (instead of Na₂O) and Fe₂O₃ (instead of Al₂O₃) does not cause any appreciable changes in glass structure. The addition of SrO, CoO, CaO, SO₃, NaCl, and simulated high-level radioactive waste oxides somewhat reduces the degree of polymerization of the structural network

[en] The characteristic features of sol-gel synthesis of vitreous materials are considered. The possibility of producing monolithic samples of porous xerogels and silica glasses from silica sols is shown; these samples are characterized by high uniformity and transparence in the visible and UV spectral ranges. The effect of γ-irradiation on the properties of the synthesized materials was studied

[en] A study is undertaken into the nature of the yellow coloring that occurs in cerium-containing silica glass exposed to radiation and high-temperature heat treatment. When exposed to gamma radiation doses D_γ > 10⁷ Gy and a neutron fluence Φ > 10¹⁷ n/cm² and also heat-treated in air at 1000 degrees C for 10 h, samples acquire a yellow color that is attributed to valence-coordination changes in the cerium atoms

[en] Water resistance and diffusion properties of glass materials are studied with reference to pseudobinary systems: simulated ash residue oxides ARO-Na₂O·2B₂O₃ and ARO-Na₂O·2SiO₂. The rate of sodium cation leaching is shown to decrease from increasing ARO content, reaching 10^-12, 10^-14 kg m^-2 s^-1, which satisfies relevant environmental requirements. The diffusion coefficients of sodium cations in ash-containing aluminosilicate glasses, measured by the method of integrated residual activity using the radionuclide ²²Na, are equal to 10^-12 - 10^-13 kg m^-2 s^-1 and are 4 to 5 orders of magnitude greater than the diffusion coefficients of the radionuclides ⁹⁰Sr and ¹³⁷Cs

[en] The decay of color centers in alkali borate glasses exposed to polarized optical radiation is studied. Optical irradiation of γ-colored glasses is shown to destruct all types of color centers investigated. The mechanism of decay is defined by the type of color centers excited by a given type of radiation. Decay may be due either to photoionization of electron-type centers and subsequent recombination of the released electrons with hole-type centers or to delocalization of holes from hole-type centers and their subsequent recombination with electrons from electron-type centers

[en] The absorption spectra induced by γ-irradiation and by the recording of writing the quadratic-susceptibility χ⁽²⁾ gratings are obtained for the samarium-, terbium-, and erbium-doped aluminosilicate optical fibers. The nature of the color centers, which are responsible for microscopic changes in the glass structure, is investigated

[en] The effect of vitrification parameters on heterogeneous phases that are formed by the platinum group metals (Ru, Rh, and Pd) in the phosphate and borosilicate melts under laboratory conditions is studied in simulating the solidification of high-level liquid wastes in an induction furnace with a water-cooled crucible. Among the factors affecting behavior of nuclides in these processes, most important are considerable temperature gradients (triangle T ∼ 200 K) and convective flows in the melt, small time of glass melt processing (30 min), and possibility of interaction of high-frequency field with heterogeneities of the melt

[en] The spectral-luminescent properties of radiophotoluminescent phosphate glasses are studied in the Ag₂O concentration range 0.05-4.0 wt% and at the γ-irradiation dose 10²-10⁴ Gy. At the Ag₂O concentrations not over 0.1 wt%, the radiophotoluminescence spectrum consists of a broad band, whose contour is well described by Gauss' function, with a maximum at 650 nm. At Ag₂O concentrations higher than 0.1 wt%, the radiophotoluminescence spectrum is the superposition of two Gaussian bands with intensity maxima at 650 and 450 nm. The ratio of band intensities depends on the Ag₂O concentration, conditions of the heat treatment of the irradiated samples, and irradiation dose. The correlation between the concentration dependences of radio-photoluminescence spectra and those of luminescence spectra for unirradiated glasses, which are activated with silver, is revealed

[en] The behavior of some components of high-level liquid wastes (uranium, plutonium, and radiogenic americium) when introduced into phosphate and borosilicate glassy composites was studied. By the examples of natural uranium, ²³⁹Pu, and ²⁴¹Am, the distribution of these α-particle emitters over the bulk of a glass melt was shown; their solubilities in the composites were studied; and the compositions of the heterogeneous phases formed in melts and the valence state of dissolved uranium were determined. The results of these investigations indicated the restricted solubility of some radionuclides in glassy composites