Experimental Study of Radon Exhalation Rate in Uranium-Like Rock Based on Closed Chamber Method

2018 ◽  
Author(s):  
Fuliang Jiang ◽  
Xiaoli Wang ◽  
Shuai Zhang ◽  
Xiangyang Li ◽  
Changshou Hong
Keyword(s):  
Diffusion Length ◽  
Underground Mining ◽  
Similarity Theory ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Closed Chamber ◽  
Radon Exhalation ◽  
Chamber Method ◽  
Diffusion Phenomena ◽  
Closed Chamber Method

The closed chamber method is widely used in measuring radon exhalation rate, which can avoid the error caused by the leakage and anti-diffusion phenomena. Firstly, considering the actual situation that uranium ore is difficult to obtain and have a high radioactivity, the uranium-like rock was made according to the similarity theory. Secondly, the diffusion length and intrinsic radon exhalation rate were obtained by using the closed chamber method. Thirdly, the theoretical values of radon exhalation rate made by uranium-like ore block were calculated, compared with the measured values. This study shows that the uranium-like rock block made by the best mass ratio is helpful for the subsequent experiment, and the error between the theoretical calculation and the measured value is no more than 9.14%. This indicates it is reliable to estimate radon exhalation rate by diffusion length and intrinsic radon exhalation rate and can also provide a foundation for rapidly gaining radon exhalation rate of the same type material by the closed chamber method. This study can further promote the study of the radon exhalation rate under the complex physical conditions and then better guide the protection work of radon radiation in underground mining.

Accurate measurement of the radon exhalation rate of building materials using the closed chamber method

2012 ◽  
Vol 32 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Lei Zhang ◽  
Xing Lei ◽  
Qiuju Guo ◽  
Shanqiang Wang ◽  
Xinhua Ma ◽  
...  
Keyword(s):  
Building Materials ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Closed Chamber ◽  
Radon Exhalation ◽  
Chamber Method ◽  
Closed Chamber Method

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.

scholarly journals Laboratory Experimental Laws for the Radon Exhalation of Similar Uranium Samples with Low-Frequency Vibrations

2018 ◽  
Vol 10 (8) ◽  
pp. 2937 ◽  
Author(s):  
Zi-qi Cai ◽  
Xiang-yang Li ◽  
Bo Lei ◽  
Jing-fan Yuan ◽  
Chang-shou Hong ◽  
...  
Keyword(s):  
Low Frequency ◽  
Silicon Powder ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Blank Group ◽  
Closed Chamber ◽  
Radon Exhalation ◽  
Damage Degree ◽  
Low Frequency Vibration ◽  
Uranium Tailings

It is the fact that there are lots of hazard incidents in underground uranium mines caused by radon but in-suit uranium samples were difficult to collect. Based on closed chamber method, three similar samples in different sealed ways were made in a laboratory with different material rations, namely uranium tailings, quartz sand, cement, iron powder and silicon powder to measure the radon concentrations with and without low-frequency vibrations, which was used by the experimental device for low-frequency vibration diffusion of radon. The results showed that the radon exhalation coming from the similar samples was influenced by the low frequency vibration; the results are presented as two-stage variations compared with the blank group. The radon exhalation increased with the rising vibration frequency when the frequency was 50 to 70 Hz, but fell slowly after reaching the peak radon exhalation rate. Analyses of the relations between the rock damage degree, changes in porosity and the occurrence of an inflection point in the radon exhalation rate in the samples found that they also increased when the frequency was between 0 to 80 in sample 3. The maximum porosity of the third samples was about 4.8% with a low-frequency vibration 60 Hz, while the maximum damage degree was about 0.07 at 50 Hz.

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 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.

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