Numerical Simulation on U(VI) in Uranium Tailing Impoundment Affected by Acid Rain

2014 ◽  
Vol 986-987 ◽  
pp. 713-718
Author(s):  
Shuang Long Ouyang ◽  
Shu Zhan Li ◽  
Shu Kui Zhou ◽  
Hua Li ◽  
Hai Hao Jiang ◽  
...  
Keyword(s):  
Acid Rain ◽  
Maximum Speed ◽  
Radionuclide Migration ◽  
Effect Assessment ◽  
Groundwater Movement ◽  
Partitioning Coefficient ◽  
Tailings Impoundment ◽  
Maximum Value ◽  
And Migration ◽  
Uranium Tailings

As acid rain getting more and more serious, increasing attention is given to environmental effect assessment of uranium tailings under the condition of acid rain. In the paper, influence of acid rain to partitioning coefficient (Kd) of U(VI) in soil was studied, and migration of radionuclide uranium in soil was simulated by computer. The static experiment results showed that the Kd value of U(VI) in soil reaches minimum value when pH is 2.0. When 2.0<pH<3.5, the Kd showed a rising tendency;The Kd in soil reaches maximum value when pH is 3.5. And when 3.5<pH<8.0, the Kd showed a decreasing tendency. This paper has taken a large uranium tailings impoundment in South China as an example studied by VisualModflow. After setting up models of groundwater movement and radionuclide migration in the study area, migration tendency of radionuclide U(VI) was simulated and pollution of radionuclide to environment was predicted. The results of simulation show that the migration of uranium speed to be the slowest when pH = 2.0, and the figure to be the fastest when pH = 3.5. Furthermore, maximum speed is about 1.24 times of minimum speed.

Numerical Simulation of Atmospheric Migration of Particles from Uranium Tailings Impoundment

2012 ◽  
Vol 253-255 ◽  
pp. 1014-1018
Author(s):  
Xiao Yong Peng ◽  
Fen Wan ◽  
Qing Fang Xie ◽  
Xin Zhang ◽  
Shuai Huang
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Particle Concentration ◽  
Dust Emission ◽  
Local Concentration ◽  
Discrete Phase Model ◽  
Local Pollution ◽  
Tailings Impoundment ◽  
And Migration ◽  
Uranium Tailings

Based on the discrete phase model (DPM), this paper studies the concentration distribution and settlement regularity of particles which sizes are 10μm and 100μm under the wind speed of 0.5, 1, 2, and 4m/s with the method of numerical simulation. The simulation results show that the particle concentration of 10μm at the downwind direction of tailing is constantly decreasing with the increase of wind speed and migration distance, and the particle concentration of 100μm is gradually increasing, as well as the local pollution also become gradually worse. As wind speed is 0.5m/s, the local concentration of 10μm particles at the beach face of uranium tailings impoundment is higher, and there is much deposition within 2000m of the downwind direction. While the dust emission rate of 100μm is less and its concentration is lower.10μm particles are taken away by the wind, and its concentration would fall rapidly with wind speed increased to 4.0m/s. The concentration of 100μm particle would increase and local pollution becomes more serious.

Numerical Simulation of Radon Atmospheric Dynamic Diffusion from a Flat Ground Uranium Tailings Impoundment

2013 ◽  
Vol 807-809 ◽  
pp. 628-631
Author(s):  
Xiao Yong Peng ◽  
Xin Zhang ◽  
Shuai Huang ◽  
Xu Sheng Chai ◽  
Lan Xia Guo
Keyword(s):  
Numerical Simulation ◽  
Mass Fraction ◽  
Space Distribution ◽  
Time And Space ◽  
Tailings Impoundment ◽  
Diffusion Characteristics ◽  
Atmospheric Dynamic ◽  
Uranium Tailings ◽  
Dynamic Diffusion ◽  
Flat Ground

with a flat ground uranium tailings impoundment as the object of the paper, CFD technology was used to study the atmospheric dynamic diffusion characteristics and the evolution of time and space distribution of radon in the uranium tailings impoundment. Results show that, within 1500m range of the leeward of uranium tailings impoundment the falling gradient of radon mass fraction improves with distance increases at the same moment, however the falling gradient flattens with the increase of time gradually; During the first 30 minutes, the radon mass fraction of tailings impoundment in the leeward direction has a larger growth gradient, then flattens out slowly, and stabilizes after 75 minutes.

Leaching and migration of Np, Pu, and Am from α-doped SON68 HLW glass in contact with dense clay

2006 ◽  
Vol 932 ◽  
Author(s):  
Elie Valcke ◽  
Mireille Gysemans ◽  
Hugo Moors ◽  
Pierre Van Iseghem ◽  
Nicole Godon ◽  
...  
Keyword(s):  
Glass Frit ◽  
High Density ◽  
Radionuclide Migration ◽  
Colloidal Transport ◽  
Boom Clay ◽  
Backfill Materials ◽  
Powdered Glass ◽  
And Migration ◽  
Radionuclide Leaching

ABSTRACTIn the frame of an integrated in situ test on the alteration of the SON68 reference glass in realistic disposal conditions, the leaching of Np, Pu, and Am from α-doped SON68 glass samples and their migration in three clay-based backfill materials at high density was measured. The addition of powdered glass frit to a Ca-bentonite decreased the glass alteration by two orders of magnitude, and resulted in a concomitant decrease of the radionuclide leaching in comparison with dried Boom Clay, which is the more agressive backfill. All actinides were selectively retained in the alteration layer, but the retention degree was lower for Np than for Pu and Am. All backfill materials proved to be efficient barriers against radionuclide migration. For nearly all radionuclides and backfill materials, the migration profile showed a contribution of colloidal transport.

Research Status and Influencing Factors for the Radon Emanation of Uranium Tailings Impoundment

2011 ◽  
Vol 356-360 ◽  
pp. 1679-1683
Author(s):  
Xiao Yong Peng ◽  
Zhen Hao Liu ◽  
Lin Yao ◽  
Qing Fang Xie ◽  
Fen Wan
Keyword(s):  
Influencing Factors ◽  
Physical Experiment ◽  
Sampling Time ◽  
Theoretical Research ◽  
Radon Emanation ◽  
Research Status ◽  
Management Standards ◽  
Tailings Impoundment ◽  
Migration Mechanism ◽  
Uranium Tailings

The influencing factors on radon emanation rate of uranium tailings storehouse, migration mechanism, theoretical research of the radon emanation and research status of radonmetry were introduced. Reasonable measurement, network, sampling time and measuring times are very necessary to the measurement of radon emanation rate of uranium tailings. Combining numerical simulation, physical experiment simulation and field test, put forward reasonable management standards for decommissioning uranium tailings.

Numerical Simulation of the Vegetation Effect on Tailing Sand Atmospheric Transport in Uranium Tailing Impoundment

2013 ◽  
Vol 726-731 ◽  
pp. 1613-1618
Author(s):  
Xiao Yong Peng ◽  
Xin Zhang ◽  
Shuai Huang ◽  
Xu Sheng Chai ◽  
Lan Xia Guo ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Vegetation Cover ◽  
Particle Concentration ◽  
Atmospheric Transport ◽  
Simulation Method ◽  
Horizontal Distance ◽  
Migration Distance ◽  
And Migration ◽  
Uranium Tailings ◽  
Vegetation Effect

For two conditions of (non-) vegetation cover in uranium tailings beach face, the concentration distribution and settlement regularity of tailing sand with diameter of 10μm at speed of 0.5, 1, 2, and 4 m/s was studied by numerical simulation method. Results shows, with the increase of wind speed and migration distance, particle concentration decreases. Compared with the non-vegetation cover condition, particles concentration in the condition of with vegetation cover is significantly higher than the condition that without vegetation cover; but along with the increase of horizontal distance, the concentration lowers than the latter gradually.

scholarly journals Experimental Study on the Fine-Grained Uranium Tailings Reinforced by MICP

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Rong Gui ◽  
Yu-xiang Pan ◽  
De-xin Ding ◽  
Yong Liu ◽  
Zhi-jun Zhang
Keyword(s):  
Discharge Rate ◽  
Physiological Activity ◽  
Friction Angle ◽  
Solution Concentration ◽  
High Concentration ◽  
Sand Column ◽  
Sporosarcina Pasteurii ◽  
Fine Grained ◽  
And Migration ◽  
Uranium Tailings

Sporosarcina Pasteurii was chosen for the experiment to study the effect and mechanism of fine-grained uranium tailings reinforced by MICP. The biochemical characteristics of strains and microbial immobilization in uranium tailings were analyzed. The results showed that the CaCO3 production rate is positively correlated with the physiological activity of Sporosarcina Pasteurii and the concentration of calcium sources, and the higher the solution concentration of CaCl2, the lower the discharge rate of bacterial liquid from the sand column, but high concentration of CaCl2 solution will affect the uniform distribution and migration of bacteria in the uranium tailings. After 16 days, the direct shear was used to test the reinforcement effects of fine-grained uranium tailings by MICP. The cohesive force and the internal friction angle of fine-grained uranium tailings were increased by 140.1% and 46.7%. The production amount of CaCO3 is 138.89 kg/m3. The results showed that the MICP-reinforced technology can effectively improve the shear strength of the uranium tailings, and the experiment provides a new method for the reinforcement of the fine-grained uranium tailings dam.

Factors Analysis about the Dam-Break of the Uranium Tailings

2014 ◽  
Vol 1051 ◽  
pp. 495-499
Author(s):  
Fang Ke Lv ◽  
Yong Liu ◽  
Zan Guo
Keyword(s):  
Safety Monitoring ◽  
Environment Pollution ◽  
Property Damage ◽  
Practical Situation ◽  
Related Factors ◽  
Structure Damage ◽  
Tailings Impoundment ◽  
Factors Analysis ◽  
Hazard Sources ◽  
Uranium Tailings

The uranium tailings is a typical major hazard sources because of its specificity, which could cause serious casualties, property damage and environment pollution in the event of an accident, and thus calls for the attention of everyone. In this paper, we will connect with the practical situation of the uranium tailings, identifying the factors of the dam, such as stability failure of dam slope, overtopping, structure damage, seepage damage and so on. To analyze the related factors and put forward countermeasures based on the analyzed results to control the harmful factors, this will lay the foundation for improving the safety monitoring and security management of uranium tailings impoundment.

Numerical Simulation of Atmospheric Diffusion of Radon Emanating From Flat Ground Uranium Tailings Impoundment in Different Heights

2012 ◽  
Vol 518-523 ◽  
pp. 1677-1681 ◽  
Author(s):  
Xiao Yong Peng ◽  
Zhen Hao Liu ◽  
Qing Fang Xie ◽  
Xin Zhang ◽  
Fen Wan ◽  
...  
Keyword(s):  
Radon Concentration ◽  
Concentration Distribution ◽  
National Standard ◽  
Radon Emanation ◽  
Atmospheric Diffusion ◽  
Tailings Impoundment ◽  
Effective Doses ◽  
The Difference ◽  
Uranium Tailings ◽  
Flat Ground

The atmospheric diffusion and concentration distribution of radon (emanation rate is 6.06 Bq/m2s ) emanating from the flat ground uranium tailings impoundment at various heights(0m, 10m, 20m, and 30m) are simulated. The numerical results show that the different height of the tailings impoundment will mainly influence the radon concentration that could change in the range of 16~250 Bq/m3 at the downwind region of 0-300m. The radon concentration and annual effective doses for public from radon decrease sharply with the increasing distance away from tailings impoundment, are higher than that of the decommissioned uranium tailings impoundment (its height is 30m, radon emanation rate is 0.74 Bq/m2s ). The annual effective doses for public from radon are highly up to 1.12 mSv/a, and are 0.12 mSv/a greater than the national standard in the range of 800m. Considering the difference of average radon emanation rate and other factors, the protective distance from radon should be adjusted appropriately.

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