# Cementation of Boron-Containing Liquid Radioactive Waste at Elevated Temperature

Yu. A. Olkhovik1, Yu. G. Fedorenko1, A. N. Rozko2, S. Yu. Saenko3,
V. A. Shkuropatenko3

1SI “The Institute of Environmental Geochemistry of the National Academy of Sciences of Ukraine”, 34 a, Palladin ave., Kyiv, 03142, Ukraine
2M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation of the National Academy of Sciences of Ukraine, 34, Palladin ave., Kyiv, 03142, Ukraine
3Institute of Solid-State Physics, Materials Science and Technology of the National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademichna st., Kharkiv, 61108, Ukraine

DOI: doi.org/10.31717/2311-8253.19.1.7

### Abstract

The features of cementation of borate-containing concentrated salt solutions, which, in their composition simulate liquid radioactive solutions of atomic power plants with WWER reactors, are considered. The addition of salts of imitate of crystallization centers in the form of bentonite powder and portland cement in an over-saturated solution (800 g/dm3) promotes the formation of a large number of small crystals of salts, including sodium metaborate, in the compounds.

The purpose of the work was to investigate the effect of temperature and the bentonite during cementation of borate liquid radionuclide radwaste imitation on the normalized indexes of compounds. Tests for compression of samples of compounds were carried out on the electromechanical press of the brand ZD 10/90 (production – Germany), the maximum load – 10 t. Imitation of irradiation was carried out on an electron accelerator LU-10 with energy of 10 MeV, the rate ofleach-ing of stable cesium was determined by an atomic absorption spectrophotometer AA 8500F «Jarrel-H», annealing of samples of compounds – using the device Vick.

The samples of cement compounds that have been synthesized under these conditions have a compressive strength of more than 4.9 MPa, and the satisfactory strength of the samples is preserved after y-irradiation with a dose of 10 kGy and after 30 cycles of freezing-thawing. The visual inspection of irradiated samples of mechanical fracture marks in the form of chips and cracks and color changes did not reveal. The normalized leaching rate of 10-3g/(cm2·d) is achieved on 107-M46 days.

The equations that associate the masses of imitate, water, cement and bentonite salts with the term of the beginning of gripping, the limit of compressive strength and the time of reaching the normalized value during leaching are obtained. The equations allow taking into account the change in the values of the parameters when optimizing the relations between the components.

Keywords: radioactivity, radiation firmness, speed of lixiviating, speed of consolidation, mechanical durability.

### References

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Published
2019-05-31

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