scholarly journals Outdoor 222Rn behaviour in different areas of Slovakia

Nukleonika ◽  
2016 ◽  
Vol 61 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Karol Holý ◽  
Monika Műllerová ◽  
Martin Bulko ◽  
Oľga Holá ◽  
Terézia Melicherová
Keyword(s):  
Time Series ◽  
Significant Influence ◽  
Activity Concentration ◽  
Sandy Soils ◽  
Simple Approach ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Hilly Terrain ◽  
Radon Exhalation ◽  
Linear Dependency

Abstract Radon activity concentration (RAC) in the outdoor atmosphere was monitored in four localities of Slovakia. The distance between the localities were up to 130 km. The localities had a diverse orography, ranging from flatland to hilly terrain. A significant influence of orography and 226Ra and 222Rn content in soil on diurnal time series of RAC was found. A simple approach of determining radon exhalation rate from soil based on the increase of RAC from daily minima to maxima and removal characteristic of radon is presented. A linear dependency between radon exhalation rate from the soil and RAC in the soil gas at a depth of 0.8 m was found for sandy soils.

Impact of soil incorporation of biochar on radon emission

2020 ◽  
Author(s):  
Kamil Szewczak ◽  
Katarzyna Wołoszczuk ◽  
Sławomir Jednoróg ◽  
Anna Rafalska-Przysucha ◽  
Łukasz Gluba ◽  
...  
Keyword(s):  
Water Retention ◽  
Activity Concentration ◽  
Radioactive Material ◽  
Satellite Monitoring ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Emanation Coefficient ◽  
Radon Emission ◽  
The Impact

<p>Biochar (charcoal made from biomass in the pyrolysis process) has found broad application in agriculture. The research performed with biochar revealed the positive impact of biochar application for chemical and physical properties of soil. Biochar was also used as an material for decontamination of soil from heavy metals and pesticides. The improved water retention of soil after biochar application was shown as well. There are particular research concerning the usage of biochar as an material for decontamination of soil from anthropogenic radioactive material including Cs-137 and Sr-90 deposited after nuclear weapon test. However, the biochar find the most practical application in agriculture for improvement of crops efficiency and water retention of soils. The typical application amount of biochar for agricultural purpose varies from 40 to 100 Mg ha<sup>-1</sup>.</p><p>Actually, there are numerous research activities focused on the direct impact of biochar on physical and chemical soil properties. Simultaneously lack of information are available for issue if and how biochar impact for environment radioactivity. As one of that impact could be  the influence on radon emission from soil surface. The aim of presented work was to investigate the impact of biochar application into the soil for the radon emission process.</p><p>The research objects were soil samples collected from experimental fields with biochar applied at doses from 1 to 100 Mg ha<sup>-1</sup>. Two type of biochar were investigated – first biochar produced from sunflower husk at temperature of 650°C and second biochar produced from wood chips at temperature of 650°C. The radon emanation coefficient were assessed using active cumulative technique incorporating AlphaGUARD instrument equipped with sealed accumulation box.  In addition, we directly measured radon exhalation rate at the experimental fields. As the emanation coefficient calculation require the information on Ra-226 activity concentration, the gamma spectrometry analysis using HPGe detector were performed for samples collected on particular field.  </p><p>The results of activity concentration assessments shown that the most visible effect of biochar application into the soil is associated with the reduction of soil bulk density by this material. No significant changes in activity concentration depending on the biochar dose applied were observed for Ra-226. Fluctuation in radon exhalation rate as well as in emanation coefficient, depending on the biochar dose (from 1 to 100 Mg ha<sup>-1</sup>) were observed and presented.</p><p>The research was partially conducted under the projects “Water in soil – satellite monitoring and improving the retention using biochar” no. BIOSTRATEG3/345940/7/NCBR/2017, which was financed by the Polish National Centre for Research and Development in the framework of “Environment, agriculture and forestry” – BIOSTRATEG strategic R&D programme.</p>

FRACTAL AND CHAOS ANALYSIS FOR DYNAMICS OF RADON EXHALATION FROM URANIUM MILL TAILINGS

Fractals ◽  
2016 ◽  
Vol 24 (03) ◽  
pp. 1650029 ◽  
Author(s):  
YONGMEI LI ◽  
WANYU TAN ◽  
KAIXUAN TAN ◽  
ZEHUA LIU ◽  
YANSHI XIE
Keyword(s):  
Time Series ◽  
Lyapunov Exponent ◽  
Hurst Exponent ◽  
Correlation Dimension ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Mill Tailings ◽  
Uranium Tailings ◽  
Uranium Mill Tailings

Tailings from mining and milling of uranium ores potentially are large volumes of low-level radioactive materials. A typical environmental problem associated with uranium tailings is radon exhalation, which can significantly pose risks to environment and human health. In order to reduce these risks, it is essential to study the dynamical nature and underlying mechanism of radon exhalation from uranium mill tailings. This motivates the conduction of this study, which is based on the fractal and chaotic methods (e.g. calculating the Hurst exponent, Lyapunov exponent and correlation dimension) and laboratory experiments of the radon exhalation rates. The experimental results show that the radon exhalation rate from uranium mill tailings is highly oscillated. In addition, the nonlinear analyses of the time series of radon exhalation rate demonstrate the following points: (1) the value of Hurst exponent much larger than 0.5 indicates non-random behavior of the radon time series; (2) the positive Lyapunov exponent and non-integer correlation dimension of the time series imply that the radon exhalation from uranium tailings is a chaotic dynamical process; (3) the required minimum number of variables should be five to describe the time evolution of radon exhalation. Therefore, it can be concluded that the internal factors, including heterogeneous distribution of radium, and randomness of radium decay, as well as the fractal characteristics of the tailings, can result in the chaotic evolution of radon exhalation from the tailings.

Analysis of the Ventilation Effects on Radon-222 Exhalation in a Dead-End Tunnel

2015 ◽  
Vol 713-715 ◽  
pp. 304-313
Author(s):  
Shu Guang Wang ◽  
Wei Yang ◽  
Qing Chen ◽  
Jian Hua Chen ◽  
Cong Han
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Natural Ventilation ◽  
Weather Conditions ◽  
Calculation Model ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Exhaust Ventilation ◽  
Dead End

The regularity of radon exhalation rate in the over-broken granite tunnel is susceptible to weather conditions and ventilation styles. Based on the calculation model of radon exhalation in tunnel, some experiments have been carried out to analyze the variations of radon exhalation in cases of natural ventilation, blowing ventilation and exhaust ventilation separately. The results show that there is a linear relation between the radon exhalation and the natural ventilation quantity, and also between the radon exhalation and the ambient temperature; the radon exhalation in the case of exhaust ventilation is 63% higher than that in the blowing case under the condition of the same ventilation quantity and ambient temperature. Therefore, it is suggested that operation in the tunnel in high temperature be avoided in summer, and the blowing ventilation be adopted as an effective way for ventilation.

scholarly journals Effect of Ultrasonic Treatment on Radon Exhalation from Porous Media: An Experimental Case Study

2018 ◽  
Vol 10 (9) ◽  
pp. 3005
Author(s):  
Ling-feng Xie ◽  
Shu-liang Zou ◽  
Xiang-yang Li ◽  
Chang-shou Hong ◽  
Hong Wang ◽  
...  
Keyword(s):  
Porous Media ◽  
Moisture Content ◽  
Ultrasonic Wave ◽  
Linear Correlation ◽  
Experimental Results ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Experimental Apparatus ◽  
Positive Linear Correlation

Radon is internationally recognized as one of the seven seismic precursors. A self-assembly ultrasonic generator and experimental apparatus for radon measurement were utilized to explore the radon exhalation regularities of water-bearing porous media under different ultrasonic intensities. The experimental results showed that there was a coupling relationship among radon exhalation rate, moisture content, and ultrasonic frequency. With the increase of the frequency of the ultrasonic wave, its effect on the promotion of radon exhalation rate was found to be a more obviously positive linear correlation. The radon exhalation rate, which could climb to a maximum value of 0.179 Bq·m−2·s−1 in a naturally air-dried sample, increased at first and then decreased along with increased moisture content. Moreover, this study found that the ultrasonic wave had the most remarkable promoting effects on the radon exhalation rate of porous media with high moisture content, and there is a positive linear correlation between the growth rate of the radon exhalation rate and moisture content. The experimental results could provide a beneficial reference for the continual monitoring of radon in a seismically active belt and an explanation of radon anomalies; however, the proposed experimental model was simplified, so further insights are strictly required for a reliable correlation with the real monitoring of radon in a seismically active belt.

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