Studies of HTO transport and oxidation in unsaturated soil

Abstract

A paper presents results of studies of HTO transport in unsaturated soil in the vicinity of long-term emission source and tritium oxidation by soil microorganisms. The objective of the first study was to determine the vertical profile of tritium from surface to lOm-depth using boreholes. The boreholes were sampled every Im for measurements of tritium in the soil water. The objective of the second study was to determine tritium oxidation activity of soil in laboratory environment depending on temperature, tritium activity, humidity, etc. A special apparatus in which a mixture of air, water vapour and tritium gas is pumped through the soil material under study was used to determine soil oxidation activity. The amount of HT converted into HTO in the soil sample during a certain period of time was used to determine the tritium reaction rate This rate varies, depending on the catalytic and/or biological activity of the material. The knowledge of the reaction rale can help to estimate HT deposition rate of HT onto the surface of an ureusturbed soil sample. A theoretical treatment based on simplifying assumptions has shown that the deposition rate can be expressed by the reaction rate and the effective diffusion coefficient of HT in the porous material.The studies are performed in frame of ISTC project 654,

Ionizing radiation long-term impact on biota in water bodies with diffferent levels radioactive contamination in belarusian sector of chernobyl nuclear accident zone

“…For both reservoirs of the ChZ significant positive correlation between the 137 Cs activity in mollusks and bottom sediments was established [2]. Therefore the character of mollusks' -activity dynamics in them in 1986-2008 is similar to that for bottom sediments (Fig.…”

“…The deterioration of organisms' physiological condition, the violations of their development and accumulation of the latent mutations can be shown up in the succeeding generation [1]. On the other hand, the process of radioadaptation expressing in increase of population radioresistance was noted in a number of species [2]. Therefore continuation of radioecological researches in aquatic ecosystems within ChZ will allow not only the trace of long-term dynamics of their radioactive pollution, but also give a more complete estimation of the effects of chronic impact of the radiating factor on their biota and trends of radioadaptive processes in it.…”