No abstract available

[en] The separation condition of strontium from fission products using SISAK system and yttrium from Sr-Y mixture was studied. The separation process was optimized. The method that separates Sr-Y after separation of strontium from fission products was selected, which was based on the half-life difference between ⁹⁴Sr and ⁹⁵Sr. Combined the fast chemistry separation and decay characteristic, ⁹⁵Y was separated successfully in the mini-reactor in CIAE. The recommended technological process was given. (authors)

[en] A method is described for counting up to six gamma nuclides simultaneously in a three channel counter. It requires two counting passes and a description is given of the counter modification which automatically adjusts the windows between passes. The variance in the results is a function of count rate and counting time and it shows remarkable uniformity for all nuclides

[en] Short communication

No abstract available

[en] The fission product separator Ostis at the Institute Laue-Langevin at Grenoble (France) was used for the investigation of the β-decays and the level schemes of short-lived Rb, Sr and Y isotopes with A = 95, 97 and 99. The studies in the mass chains 95 and 97 were made using a surface ionization source to provide Rb isotopes whereas the mass chain 99 was investigated using an high temperature ion source. The study of these nuclei close to ⁹⁸Sr and ¹⁰⁰Zr where a shape coexistence was evidenced is of great interest. Single γ-ray and conversion electron spectra, and prompt and delayed γ-γ and β-γ coincidences were measured. The level schemes of ⁹⁵Sr, ⁹⁵Y, ⁹⁷Sr and ⁹⁷Y were established or extended and a preliminary level scheme is given for ⁹⁹Y. (orig.)

[en] It is known that the vegetation, along with the climatic conditions and soil type, is one of the key components of terrestrial ecosystems. They are also first to respond to the substrate contamination with radionuclides, metals and organic substances. Biological effects observed in natural plant populations are associated with both presence of mobile compounds of pollutants in abiotic components of the ecosystem and their role in the metabolism of the plant. The goal of the study was to assess the impact of water and sediment contamination with artificial radionuclides and toxic non-radioactive compounds, on the reproductive capacity of estuarial plants using seed germination. Contaminated sites are located in flood plain of the Techa River (Chelabinsk region, Russia) between Muslumovo and Brodokalmak settlements. Radioactive contamination of the territory resulted from increased specific activities of ¹³⁷Cs and ⁹⁰Sr in water and sediments due to the accidents on the Mayak Production Association. Reference sites were chosen in the flood plains of Brusianka and Sysert' rivers (Sverdlovsk region, Russia). Reference sites are located out of the Eastern Ural Radioactive Trace. Seeds of Butomus umbellatus L. and Alisma plantago-aquatica L., which are common estuarine plant communities in this area, were collected. Specific activities of dose-forming radionuclides in the Techa river water vary from 120 up to 200 mBq/l for ¹³⁷Cs and from 26 up to 45 mBq/l for ⁹⁰Sr; and in sediments 720-10150 Bq/kg and 600-1500 Bq/kg for ¹³⁷Cs and ⁹⁰Sr correspondingly. Specific activities of ¹³⁷Cs and ⁹⁰Sr in water and sediments of both reference rivers do not exceed global fallout levels. B. umbellatus seeds germination was low for plant populations of both reference and contaminated sites. However, a significant (p<0.01) difference was found - the value was higher for reference populations (17.4 ±3.5 %) as compared with the ones from contaminated territory (from 1.2 up to 7.75 %). There was no significant difference in seed germination among the plant populations from two contaminated sites. Germination of A. plantago-aquatica seeds was higher as compared with B. umbellatus and was equal to 32-34 % for reference populations. The index values for population from radioactively contaminated territory were significantly lower (from 5 up to 9 %). We hypothesized that the reproductive capacity of the plants depends on radionuclide specific activities and concentrations of toxic non-radioactive compounds in water and sediments. Stepwise regression analysis showed that A. plantago-aquatica seeds germination decline with increase in ¹³⁷Cs specific activity in sediments (R²=0.97, SR=2.6, F=72.2, pF=0.001). The dependency is described with the following equation: A. plantago-aquatica germination=33.24 - 1.04*[¹³⁷Cs], where [¹³⁷Cs] is the specific activity ¹³⁷Cs in sediments. Increase in specific activity of ⁹⁰Sr in water and As concentration in sediments resulted in decrease of B. umbellatus seeds germination (R2=0.95, SR=1.6, F=28.2, pF=0.01). The dependency is described with the equation: B. umbellatus germination=19.7-0.27*[⁹⁰Sr] -1.3*[As], where [⁹⁰Sr] is ⁹⁰Sr specific activity in water, [As] - As concentration in sediments. Thus decrease in the reproductive capacity of natural estuarine plant populations is significantly dependent on the specific activities of long-lived artificial radionuclides in water and sediments. (authors)

No abstract available

[en] The half-life and the multipolarity for the 213 keV transition in ⁹³Sr have been determined to be (4.6 ± 0.3) ns and E2 (≤ 15 % M1) from β-γ delayed and x-γ coincidences, respectively. The half-life for the 204 keV transition in ⁹⁵Sr was also determined to be (20.9 ± 0.5) ns. The reduced transition probabilities are deduced as B(E2) = (261_-43⁺¹⁷) e²fm⁴ for the 213 keV transition and B(E2) = (71 ± 2) e²fm⁴ for the 204 keV transition. These B(E2) values are comparable to the Weisskopf estimates and to those for the similar transitions in the neighbouring nuclei. (author)

[en] Using the ⁹⁵Rb activity mass-separated by KUR-ISOL, the absolute emission probabilities of the γ rays of ⁹⁵Rb at 352.0 keV, ⁹⁵Sr at 685.6 keV and ⁹⁵Y at 954.2 keV have been determined by an affiliation method. The log f₁t value for the first-forbidden unique β^-decay of ⁹⁵Y to the ground state of ⁹⁵Zr has also been determined. The systematics of similar transitions in Y isotopes are compared with theoretical predictions. (author)