Fractal Analysis of Spatial Distribution of Radon Exhalation Rates of Uranium Mill Tailings

2012 ◽  
Vol 524-527 ◽  
pp. 584-587
Author(s):  
Yan Shi Xie ◽  
Kai Xuan Tan ◽  
Liang Chen ◽  
Kai Guang Hu ◽  
Zheng Qing Wang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Fractal Structure ◽  
Pore Connectivity ◽  
Fractal Method ◽  
Radon Exhalation ◽  
Two Dimension ◽  
Radium Content ◽  
Mill Tailings ◽  
Radon Exhalation Rates ◽  
Uranium Mill Tailings

A uranium mill tailings, located in Guangdong, was selected for spatial distribution of the radon exhalation rates measured by local static method. The two-dimension surface of radon exhalation rates was established by Surfer using the data of spatial distribution of radon exhalation rates measured at August 14, 2007 to 19 and 21, which was analyzed by fractal method of projective covering. The results show that the two-dimension surface of radon exhalation rates is of fractal structure. The fractal dimension of surface of radon exhalation rates from August 14, 2007 to 19 and 21 are 2.0535, 2.0173, 2.0029, 2.0084, 2.0079, 2.0057 and 2.0034, respectively, which indicates that the complexity of spatial distribution of the radon exhalation rates at 14 and 15 are larger than that of the other days. The phenomenon results from the change of precipitation and temperature, as well as the features of uranium mill tailings, including mineral composition, particle size, radium content, porosity and pore connectivity, etc.

scholarly journals Analysis of spatial distribution and inventory of radioactivity within the uranium mill tailings impoundment

2015 ◽  
Vol 16 (3) ◽  
pp. 254-262 ◽  
Author(s):  
D.O. Bugai ◽  
◽  
G.V. Laptev ◽  
O.S. Skalskyy ◽  
T.V. Lavrova ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Tailings Impoundment ◽  
Mill Tailings ◽  
Uranium Mill Tailings

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.

scholarly journals Radon exhalation rates of some granites used in Serbia

2015 ◽  
Vol 30 (2) ◽  
pp. 145-148
Author(s):  
Mladen Nikolic ◽  
Rodoljub Simovic
Keyword(s):  
Measurement Technique ◽  
Back Diffusion ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Closed Chamber ◽  
Radon Measurement ◽  
Radon Exhalation ◽  
Radium Content ◽  
Radon Exhalation Rates ◽  
Closed Chamber Method

In order to address concern about radon exhalation in building material, radon exhalation rate was determined for different granites available on Serbian market. Radon exhalation rate, along with mass exhalation rate and effective radium content were determined by closed chamber method and active continuous radon measurement technique. For this research, special chambers were made and tested for back diffusion and leakage, and the radon concentrations measured were included in the calculation of radon exhalation. The radon exhalation rate ranged from 0.161 Bq/m2h to 0.576 Bq/m2h, the mass exhalation rate from 0.167 Bq/kgh to 0.678 Bq/kgh, while the effective radium content was found to be from 12.37 Bq/kg to 50.23 Bq/kg. The results indicate that the granites used in Serbia have a low level of radon exhalation.

The influence of fractal size distribution of covers on radon exhalation from uranium mill tailings

2012 ◽  
Vol 47 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Kaixuan Tan ◽  
Zehua Liu ◽  
Liangshu Xia ◽  
Junwen Lv ◽  
Hanqiao Hu
Keyword(s):  
Size Distribution ◽  
Radon Exhalation ◽  
Mill Tailings ◽  
Fractal Size ◽  
Uranium Mill Tailings
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