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Information × Registration Number 0226U001752, (0124U000530) , R & D reports Title Determination of transformation processes of uranium compounds in lava-like fuel-containing materials of the Chernobyl NPP popup.stage_title Виготовлення макетного зразка пристрою до рентгенівського дифрактометра. Head Mykhailov Ihor F., Доктор фізико-математичних наук Registration Date 30-01-2026 Organization National Technical University "Kharkiv Polytechnic Institute" popup.description1 The goal of the project is to determine the decomposition of uranium compounds with light elements, which arose within 37 years after the accident at the Chernobyl nuclear power plant; development of recommendations for stopping the degradation of Chernobyl lava, which preserves radioactively dangerous products of the accident. popup.description2 On the upgraded SPRUT spectrometer, the ratios of Compton and Rayleigh scattering peaks IC/IR of heavy metals were measured depending on the temperature and exposure time in a humid air atmosphere. Unstable heavy metal compounds close to UO2-based compounds in terms of effective atomic number and scattering peak ratio were selected. The kinetics of transformations during moisture removal from mixtures of heavy metals (lead and bismuth) was studied, as well as the transformations of WC-Si mixtures as multilayer films with nanolayers of 13 to 105 Ǻ upon annealing. To ensure the required sensitivity, a special X-ray optical scheme with complex secondary targets has been developed. Experimental calibration of the ratio of coherent and incoherent scattering peaks was performed using standard samples based on uranium dioxide. At the value of the parameter sin/=1,57Å-1, the experimental ratio for UO2 is 0.12, which corresponds to theoretical calculations (0.13). Changes to the X-ray optical scheme of the mock-up sample were determined to ensure quantitative measurements. The following interaction process has been investigated: 1) zirconium and nickel films with a humid air atmosphere; 2) tungsten with silicon and carbon in nanolayer structures during vacuum annealing. An increase in the sensitivity of kinetic curves with an increase in the energy of the probing radiation quanta has been proven. It has been experimentally determined that under such conditions for heavy metals with atomic number Z80 (Pb, Bi) the relative change in the ratio is only a few percent per one weight percent of moist air in the mixture. Therefore, in the device model developed in this project, the source voltage increase to 50 keV has been adjusted and the use of secondary emitters with quantum energy up to 35 keV is planned. Technical documentation has been developed and a prototype of the X-ray spectrometer device has been assembled. The appropriate electronic equipment is being configured. Product Description popup.authors Anton I. Mykhailov Serhii A. Kniaziev Svitlana S. Borysova Anton V. Kushtym Larysa P. Fomina popup.nrat_date 2026-01-30 Close