Method of pre-concentrating for the measurement of low- level specific radioactivity at radiation researches

In long-term perspective the check point dose formation radionuclide on the overwhelming part of the territory contaminated as a result of Chernobyl catastrophe, is 137 Cs (about 70% of collective effective equivalent doze, calculated for population of the whole world as a consequence of the Chernobyl tragedy). Radioactive hyperactive particles of a fuel origin, containing 137Cs, have being transboundarily spread in the atmosphere far from the place of accident and have penetrated in Finland, Sweden and even in Japan. In this connection the major attention is given to a study of radioecology of this element. While carrying out such an investigations the measurement of rather low levels of a specific radioactivity, as a rule, is required, that is conjugated with known difficulties. For radiochemical concentrating of ionizing radiation carriers and samples preparing for spectro- and radiometry it is proposed to use new sorption materials. The synthesis of thin layers of Cu(II) and Fe(III) hexacyanoferrates (II) was performed by the method of the chemosorption layering on a matrix which represent the derivatives of polyacrylonitrile fibres. According to the data of the X-Ray study of the synthesized pellicular hexacyanoferrates, these compositions is described by the formulas Kx Cu(2-x) [Fe(CN) 6] · 4H2O and Kx Fe(4-x) [Fe(CN) 6]3. K+ -ions in these compositions are able to exchange for other ions (mainly Cs+ -ions). The research of ion-exchange kinetic K+ - 137Cs+ have been carried out by the method of limited volume with the use of a gamma-spectrometer for measurement of specific activity of solutions. Distribution coefficients of 137Cs+ -ions for Cu(II) and Fe(III) hexacyanoferrates are equal 17000 and 12000 respectively. This indicates the prospectiveness of their practical use - for example, at radiation researches during the measurement of low-level specific radioactivity