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The study of 106Ru behavior in 5, 10 and 16 g dm−3 boric acid solutions in a wide pH range carried out by three different methods revealed the regions of the radionuclide ionic and non-ionic species formation. The strong concentration-dependent boric acid effect on the physicochemical state of 106Ru leads to the destruction of larger ruthenium pseudo-colloid species and formation of smaller ones with neutral or negative charge in pH range 7.0–10.5. The formation of 106Ru complex compounds with ionic forms of boric acid–borate (polyborate) is discussed. [ABSTRACT FROM AUTHOR]

Radiochromic films composed of polymer matrices and organic dyes are widely used for routine dosimetry purposes in operation of various radiation facilities—gamma and X‐ray‐irradiation, electron accelerators, and so on. However, the sensitivity of these films rapidly decreases at doses exceeding 30–50 kGy due to a saturation of their optical response, making them unsuitable for accurate dosimetry in radiation processing of polymers and composites where doses up to 200 kGy are typically employed. To overcome this limitation, the use of inorganic substances as the coloring agents of polymer‐based radiochromic films was proposed in this paper, specifically, heteropolyacidacid H3PW12O40 (tungstophosphoric acid) in the matrix of poly(vinyl alcohol) (PVA). Nanocomposite PVA/H3PW12O40 films were prepared by solution casting and their optical responses toward 60Co gamma radiation and beams of 6 MeV electrons for a dose range of 10–200 kGy were investigated. It was established that upon exposure to gamma rays and electron beams, the films turn blue and a broad absorption band at 750 nm appears in their spectra. Importantly, the radiation‐induced optical absorption increases in a linear fashion up to the dose of 150 kGy and only slightly deviates from linearity at 200 kGy. Moreover, it was found that the PVA/H3PW12O40 films have a long shelf life, are dose‐rate independent within a wide range, and color‐stable after irradiation. All these features make the nanocomposite PVA/H3PW12O40 films promising for use as routine dosimeters and dose labels in a much wider range of high doses as compared to radiochromic films based on organic dyes. [ABSTRACT FROM AUTHOR]

Sorption of the Sr radionuclide from model seawater solutions on phosphate sorbents was studied. Sorbents were synthesized using natural dolomite by various methods. Effects of salinity and pH of solutions on the degree of sorption and the distribution coefficient of the Sr were investigated. Hydrolytic stability, phase transformation of sorbents in model seawater solutions and change of the pH were established with the aim of identifying factors, which influence on the sorption efficiency towards the Sr radionuclide. The best sorption parameters in all range of salt concentration were obtained for sorbent containing tertiary calcium and magnesium phosphates and magnesium-ammonium phosphates. [ABSTRACT FROM AUTHOR]