タグ「transuranic elements」
Author: Loganovsky K.N., Nechayev S.Yu., Perchuk I.V.
Reference: Український медичний часопис (Ukrainian Medical Magazine) , 2008
Keywords: uranium, transuranium elements, neurotoxicity, radiotoxicity, Shelter Object
Abstract: Physical-chemical properties, prevalence, using, and neuropsychiatric effects of uranium, including depleted uranium, and transuranium elements (mainly, plutonium and americium) are discussed in the article. It is shown the increasing role of these elements in connection with Chernobyl accident and the Shelter Object transformation to an ecologically safety system. In accordance to the recent data on neurotoxicity of uranium it is supposed the same toxicity for the transuranium elements. The neurophysiological examinations of the Shelter Object personnel have revealed the disorders of cerebral bioelectrical activity to be the basis for neuropsychiatric pathology development. Exposure to low and very low doses of ionizing radiation, neurotoxicity of uranium and transuranium elements, stress, as well as other non-radiation industrial hazards were assumed to be proposed as the possible risk factors. The study of biological effects of uranium and transuranium elements are crucial for radiobiology, radiation hygiene and neuropsychiatry. It is necessary to conduct large-scale studies in this field. The Shelter Object transformation to an ecologically safety system is the unique possibility to study of radiotoxical effects of uranium and transuranium elements on the human body. (full text available on web)
URL: http://www.umj.com.ua/wp-content/uploads/archive/64/pdf/31_rus.pdf?upload
Author: Vikt. L. Barsukov, M. V. Borisov
Reference: Gazette “ ГЕОХИМИЯ “ (geochemistry), 2005
ISSN: 0016-7525
Keywords: natural waters, transuranic elements
Abstract: Dissolution of solid phases of polyvalent Am, Np, and Pu in various natural waters was studied with the aid of computer thermodynamic models. The solubility of each particular phase of the transuranic elements (TUE) varies by many orders of magnitude depending on the type of water. The speciation of dissolved TUE in waters of different types is very distinctive. Free Am3+, , Pu3+, or ions dominate in some waters, whereas in other cases, the most abundant species may be hydroxo complexes, AmOH2+, , , NpO2OH0, PuOH2+, and , or carbonate, sulfate, and chloride complex ions of polyvalent TUE. Both waters and TUE phases are significantly changed during equilibration. Shifts in the pH and Eh values of water in contact with TUE phases promote partial precipitation of major components and thus change the salt composition of water. In turn, many solid TUE phases are unstable in contact with water. All Np phases are usually replaced in the models by the least soluble phase, NpO2(c), while all Pu phases are replaced by the dioxide PuO2(c). Various Am phases at the contact with various types of water are also largely transformed into a single phase: AmO2(c), Am(OH)3(c), Am carbonate, or Am hydroxycarbonate. The solubility and speciation of TUE in water reacting with the sum of Am, Np, Pu, and U solid phases are different compared with the interaction of the same water with each particular TUE. The results of our modeling can be used to elucidate the migration ability of TUE in natural waters, including the possible formation of colloidal TUE phases, and to estimate the effects of external factors, e.g., variations in R/W (integral ratio of the reacted masses of solid phase, R, and water, W) and local shifts in pH and Eh.
URL: http://www.maikonline.com/maik/showArticle.dopii=S0016702905120049&leftmenu=no
Author: Shura L.P., Karataev V.D., Kuznetsova E.G., Ardisson J., Barsi J.
Reference: Bulletin of Polytechnic University of Tomsk
ISSN: 1684-8519
Keywords: soil, radioactivity, France, Tomsk, comparison, 137cs, 238pu, 240pu, Université de Nice Sophia- Antipolis, Polytechnic University of Tomsk
Abstract: Comparative evaluation of surface radioactivity of the Tomsk district and the Mercantour National Park (France) soils caused by transuranic elements and 137Cs. The isotope ratios 238Pu/239,240Pu, 239,240Pu/137Cs и 241Am/239,240Pu are calculated by specific activity which allows to define the most probable sources of appearance of radionuclides in atmosphere. Results of the work are used for evaluation of radiation situation and defining of anthropogenic radioactivity sources on the examined territory.
URL: http://elibrary.ru/item.asp?id=9446178
Author: Konoplya E.F., Kudryashov V.P., Grinevich S.V., Korol R.A., Bazhanova N.N., Bykovsky V.V.
Reference: Gazette “РАДИАЦИОННАЯ БИОЛОГИЯ. РАДИОЭКОЛОГИЯ“ (Radiation Biology, Radioecology), 2009
doi: 10.1134/S0869803109040171
Keywords: isotope, transuranic elements, radioactive fallout
Abstract: Study of the isotopic composition and its changes in the radioactive fallout caused by the Chernobyl accident. Defines levels of transuranic elements in the main components of the ecosystem – air, soil, water, plants and animals in the Republic of Belarus. Describes the peculiar effects of transuranic elements on living organism.
URL: http://elibrary.ru/item.asp?id=13856732
Title: Characteristics of Chernobyl-derived radionuclides in particulate form in surface waters in the exclusion zone around the Chernobyl Nuclear Power Plant
Author: Takeshi Matsunaga, Takashi Ueno, Hikaru Amano, Y Tkatchenko, A Kovalyov, Miki Watanabe, Yoshikazu Onuma
Reference: Journal of Contaminant Hydrology, Volume 35, Issues 1–3, 15 December 1998, Pages 101-113
DOI: http://dx.doi.org/10.1016/S0531-5131(01)00601-X
Keywords: Chernobyl; Transuranic elements; Cs-137; Sr-90; Surface water body; Partitioning; Distribution ratio
Abstract: The distribution of Chernobyl-derived radionuclides in river and lake water bodies at 6–40 km from the Chernobyl Nuclear Power Plant was studied. Current levels of radionuclides (Cesium-137, Strontium-90, Plutonium, Americium and Curium isotopes) in water bodies and their relation to the ground contamination are presented. The investigation of the radionuclide composition of aqueous and ground contamination revealed that radionuclides on suspended solids (particulate form) originate mainly from the erosion of the contaminated surface soil layer in the zone. Apparent distribution ratios between particulate and dissolved forms are compared to known distribution coefficients.
URL: http://www.sciencedirect.com/science/article/pii/S0169772298001193
Title: The transfer capability of long-lived Chernobyl radionuclides from surface soil to river water in dissolved forms
Author: H Amano, T Matsunaga, S Nagao, Y Hanzawa, M Watanabe, T Ueno, Y Onuma
Reference: Organic Geochemistry, Volume 30, Issue 6, June 1999, Pages 437-442
DOI:http://dx.doi.org/10.1016/S0146-6380(99)00028-5
Keywords: Sr-90; Cs-137; Transuranic elements; Speciation; Surface soil; Runoff; Dissolved organic materials; Fulvic acid; Ultrafiltration; Chernobyl 30 km zone
Abstract: Hydrologic runoff is one of the main processes in which radionuclides deposited in the surface environment migrate widely in both particulate and dissolved forms. This paper focuses on the transfer capability of long lived Chernobyl radionuclides from surface soil to river water in dissolved forms. First, concentration and speciation of radioactive Cs, Sr and transuranic isotopes, such as Pu and Am, were examined in undisturbed surface soil along the river in the exclusion zone (30 km zone) near the Chernobyl Nuclear Power Plant (NPP) in order to validate the radioactive contamination characteristics. Almost all radioactivities exist in the very top surface in the undisturbed soil layer. Sr-90 in the soil was estimated to be highest in the water soluble and exchangeable fractions, which were easily accessible to river water as a dissolved fraction. Pu isotopes and Am-241 are major radionuclides in free humic and free fulvic acid fractions. Secondly, surface soil near the Sahan River was extracted with distilled water, as an analogue of rain water, to estimate the dissolved fraction in runoff components from surface soil to river water. After a filtration procedure, extracted water was treated with ultra filtration techniques separating the molecular weight fractions of beyond and below 10,000 Da. Each fraction was measured for the radioactivity and the characteristics of organic materials including humic substances. Most Pu and Am exist in the molecular weight fractions beyond 10,000 Da, in spite of the fact that most of the dissolved organic fractions exist below 10,000 Da. This means that transuranic elements such as Pu and Am are associated with mobile high molecular weight materials like fulvic acids in water leachates.
URL: http://www.sciencedirect.com/science/article/pii/S0146638099000285
