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Title: Systematical Investigations of Cs - 137 Concentration in Soils in Bansko - Razlog Region

Abstract

Systematical investigations of Cs-137 concentration in soil in Bansko - Razlog region have been performed for the first time on a total area of about 40 km2. By means of high-resolution gamma-ray spectroscopy the radio-nuclide content of soil samples has been determined. The Cs-137 deposition density following the Chernobyl accident has been estimated and compared with results obtained in other countries. The additional dose rate caused by this fallout has been estimated, too.

Authors:
; ; ;  [1];  [2];  [3]
  1. Institute for Nuclear Research and Nuclear Energy, Sofia 1000 (Bulgaria)
  2. Department of Applied Physics, Technical University - Sofia, Sofia 1000 (Bulgaria)
  3. HPC - Bulgaria, Sofia 1000 (Bulgaria)
Publication Date:
OSTI Identifier:
21057198
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 899; Journal Issue: 1; Conference: 6. international conference of the Balkan Physical Union, Istanbul (Turkey), 22-26 Aug 2006; Other Information: DOI: 10.1063/1.2733281; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CESIUM 137; COMPARATIVE EVALUATIONS; DENSITY; DEPOSITION; DOSE RATES; EASTERN EUROPE; FALLOUT; GAMMA SPECTROSCOPY; RADIOACTIVITY; RESOLUTION; SOILS

Citation Formats

Kostov, L. K., Mladenov, Ml. I., Protochristov, Ch. N., Stoyanov, Ch. P., Kobilarov, R. G., and Kostova, L. G. Systematical Investigations of Cs - 137 Concentration in Soils in Bansko - Razlog Region. United States: N. p., 2007. Web. doi:10.1063/1.2733281.
Kostov, L. K., Mladenov, Ml. I., Protochristov, Ch. N., Stoyanov, Ch. P., Kobilarov, R. G., & Kostova, L. G. Systematical Investigations of Cs - 137 Concentration in Soils in Bansko - Razlog Region. United States. doi:10.1063/1.2733281.
Kostov, L. K., Mladenov, Ml. I., Protochristov, Ch. N., Stoyanov, Ch. P., Kobilarov, R. G., and Kostova, L. G. Mon . "Systematical Investigations of Cs - 137 Concentration in Soils in Bansko - Razlog Region". United States. doi:10.1063/1.2733281.
@article{osti_21057198,
title = {Systematical Investigations of Cs - 137 Concentration in Soils in Bansko - Razlog Region},
author = {Kostov, L. K. and Mladenov, Ml. I. and Protochristov, Ch. N. and Stoyanov, Ch. P. and Kobilarov, R. G. and Kostova, L. G.},
abstractNote = {Systematical investigations of Cs-137 concentration in soil in Bansko - Razlog region have been performed for the first time on a total area of about 40 km2. By means of high-resolution gamma-ray spectroscopy the radio-nuclide content of soil samples has been determined. The Cs-137 deposition density following the Chernobyl accident has been estimated and compared with results obtained in other countries. The additional dose rate caused by this fallout has been estimated, too.},
doi = {10.1063/1.2733281},
journal = {AIP Conference Proceedings},
number = 1,
volume = 899,
place = {United States},
year = {Mon Apr 23 00:00:00 EDT 2007},
month = {Mon Apr 23 00:00:00 EDT 2007}
}
  • Rates of migration, retardation factors, and distribution coefficients of /sup 137/Cs and /sup 90/Sr were determined in the various horizons of three typical soils (podsol, ranker, and brown soil) by employing batch procedures, column experiments, and evaluating the measured distribution of these radionuclides in the field as a result of their deposition from worldwide fallout. To obtain the distribution coefficients of the radionuclides for each soil horizon from the column experiments, the radionuclide distribution in the undisturbed soil monoliths (1 m long, 30-cm diam) was determined from the outside by a scanner technique after various times. The columns were irrigatedmore » with rainwater using the same quantities as observed at the site of sampling. Tritium labeled rainwater was used to obtain the hydrodynamic properties of the soil columns (pore water velocity, dispersion coefficient, and volumetric moisture content). Assuming that the fallout investigations yielded the most realistic results, the observations suggest that column experiments performed in the laboratory under approximately natural conditions can be used to obtain fairly realistic information about the migration of /sup 137/Cs and /sup 90/Sr in these soils. The use of distribution coefficients from batch methods for the prediction of radionuclide movement, on the other hand, can be misleading, especially in soil horizons rich in organic matter.« less
  • Statistical analysis of the data set consisting of the activity concentrations of {sup 137}Cs in soils in Bansko–Razlog region is carried out in order to establish the dependence of the deposition and the migration of {sup 137}Cs on the soil type. The descriptive statistics and the test of normality show that the data set have not normal distribution. Positively skewed distribution and possible outlying values of the activity of {sup 137}Cs in soils were observed. After reduction of the effects of outliers, the data set is divided into two parts, depending on the soil type. Test of normality of themore » two new data sets shows that they have a normal distribution. Ordinary kriging technique is used to characterize the spatial distribution of the activity of {sup 137}Cs over an area covering 40 km{sup 2} (whole Razlog valley). The result (a map of the spatial distribution of the activity concentration of {sup 137}Cs) can be used as a reference point for future studies on the assessment of radiological risk to the population and the erosion of soils in the study area.« less
  • Soil concentrations of [sup 239+240]Pu, [sup 238]Pu, [sup 241]Am, [sup 90]Sr, and [sup 137]Cs are investigated in the Marche Region of Central Italy. Mean values in uncultivated soils are 3.5--8 times higher than the corresponding values in cultivated soils. Radionuclide inventories and ratios are consistent with values reported by the United nations Scientific Committee on the Effect of Atomic Radiation for this latitude. This suggests that radiocontamination in this region is mainly due to atmospheric deposition of nuclear weapon test fallout. The vertical distribution of these radionuclides is also studied. The results show that, with the exception of [sup 90]Sr,more » more than 90% of these radionuclides are contained in the first 20 cm of soil and that mobility follows the order [sup 90]Sr > [sup 241]Am > [sup 239+240]Pu, [sup 238]Pu > [sup 137]Cs.« less
  • Radiometric and mass spectrometric analyses of Cs contamination in the environment can reveal the location of Cs emission sources, release mechanisms, modes of transport, prediction of future contamination migration, and attribution of contamination to specific generator(s) and/or process(es). The Subsurface Disposal Area (SDA) at Idaho National Laboratory (INL) represents a complicated case study for demonstrating the current capabilities and limitations to environmental Cs analyses. 137Cs distribution patterns, 135Cs/ 137Cs isotope ratios, known Cs chemistry at this site, and historical records enable narrowing the list of possible emission sources and release events to a single source and event, with the SDAmore » identified as the emission source and flood transport of material from within Pit 9 and Trench 48 as the primary release event. These data combined allow refining the possible number of waste generators from dozens to a single generator, with INL on-site research and reactor programs identified as the most likely waste generator. A discussion on the ultimate limitations to the information that 135Cs/ 137Cs ratios alone can provide is presented and includes (1) uncertainties in the exact date of the fission event and (2) possibility of mixing between different Cs source terms (including nuclear weapons fallout and a source of interest).« less
  • By means of 156 samples from crater lakes of the Eiful, the /sup 137/Cs- activity of various types of soil as well as the vertical and lateral distribution of /sup 137/Cs in the soil were examined. Moreover, the content of potassium, the percentage of the organic substance, and the pH-value were determined. The reading of /sup 137/Cs and potassium was obtained by gamma spectrometry in ring cups, the contents of organic ingredients was ascertained via the carbon proportion, and the pH-value by means of a glass electrode. The content and extent of penetration of /sup 137/Cs correlate with the proportionmore » of organic substance, the content of potassium and the pH-value. Nevertheless there exists no causal dependence between these values. It seems that causal significance for the contents, the extent of penetration and the lateral distribution has to be attributed to the surface water, the texture, and the absorbent qualities of the soils as well as the topography of the region. The importance of the knowledge of the behavior of /sup 137/Cs in the soil in view of prophylaxis and single-minded taking of samples for the estimation and the reduction of the /sup 137/Cs content of slaughtered cattle is pointed out. (GE)« less