Assessment of the state of vegetation cover of recultivated dumps of uranium deposits in Northern Kazakhstan.

The purpose of this study was to assess the processes of plant community formation on recultivated dumps of spent uranium-containing industrial waste from uranium deposit mines, as well as to identify the degree of impact of agro-climatic factors, agrochemical indicators of soils of recultivated dumps, and the level of residual ionizing radiation on the productivity of the emerging vegetation cover. Studies of plant colonization of recultivated Grachevsky and Shantobinsky uranium mine dumps located in Northern Kazakhstan were carried out. The mining and technical stage of reclamation consisted of planning a dump with slopes of 15° and covering it with a 1 m layer of chestnut soil.

Fractionation of some natural radionuclides in Albic Retisol.

In the present work, the fractionation of heavy natural radionuclides was investigated in Albic Retisol in the Moscow region of Russia. Fractionation was performed using the Pavlotskaya method. U and Тh were measured via inductively coupled plasma mass spectrometry and Ra was measured using an alpha-radiometer that considered the decay of Ra isotopes and accumulation of the resulting decay-related products.

Spatial Distribution of ¹³⁷Cs in Soil of Spruce Forest in the Distant Zone of Chernobyl Fallout.

The vertical distribution of ¹³⁷Cs in Albeluvisols of the spruce forest in the Roslavl district of Smolensk region was investigated. The statistical characteristics of spatial variability and distribution laws for the activity con- centrations and activity depositions of ¹³⁷Cs in upper soil layers (forest litter, 0-5, 5-10, 10-19 cm) were de- termined. Positive correlations between the height, crown length of spruce trees and the content of ¹³⁷Cs in the soil under them were revealed.

[Distribution of 137Cs, 90Sr and their chemical analogues in the components of an above-ground part of a pine in a quasi-equilibrium condition].

The additional study of the distribution of radioactive isotopes of caesium and strontium and their chemical analogues in the above-ground components of pine in the remote from the accident period was carried out. The results of the research confirmed the existence of analogy in the distribution of these elements on the components of this type of wood vegetation in the quasi-equilibrium (relatively radionuclides) condition. Also shown is the selective possibility of using the data on the ash content of the components of forest stands of pine and oak as an information analogue.

[The comparative analysis of 137Cs, 40K, K, 90Sr and Ca allocation in builders of an ground part of wood plants in a quasi-equilibrium condition].

The examinations of allocation of radioactive isotopes of caesium and of strontium and of their chemical analogs in a stand of forest ecosystems are carried out. By results of examinations and analysis of literary data the presence of analogy in allocation of these elements on builders in quasi-balanced (concerning radionuclides) state was confirmed. The question about the opportunity of use of data about behaviour of K and of Ca is considered at an explanation of the mechanisms of redistribution of 137Cs and of 90Sr in wood plants and for buildup of mathematical models of behaviour of datas of radionuclides in ground ecosystems.