Research on the influence of surface crack development on radon exhalation in uranium tailing ponds under wet and dry cycles.

Compacted soil layers effectively prevent the migration of radon gas from uranium tailings impoundments to the nearby environment. However, surface damage caused by wet and dry cycles (WDCs) weakens this phenomenon.In order to study the effect of crack network on radon exhalation under WDCs, a homemade uranium tailing pond model was developed to carry out radon exhalation tests under five WDCs.

Experimental Study on the Effect of Wetting-Drying Cycles on Crack Development and Radon Retardation of the Covering Soil in Uranium Mill Tailing Impoundments.

The majority of uranium mill tailing impoundments in the southern part of China are located in humid subtropical regions where persistent rainfall and rapid evaporation of water after rain often occur. Under the prolonged influence of alternating wet and dry conditions, the covering soil layer of uranium mill tailing impoundments develops cracks, leading to the issue of degradation or even failure of the radon retardation effect. A beach surface of uranium mill tailing impoundments in the southern part of China is selected as the research object.

Influence of temperature on the radon concentration distribution in ramp under low-speed wind field: A numerical simulation study.

By introducing the parameters of radon exhalation rate and radon diffusion coefficient, the distribution of radon concentration field on ramp under the condition of superposition of temperature field and flow field is simulated. The simulation results show that the distribution of radon concentration in the ramp under the condition of low-speed ventilation is greatly affected by the temperature field and flow field, and the change of radon exhalation caused by temperature is the main factor leading to the change of radon concentration in the ramp. The change of temperature will cause the overall increase of radon concentration in the ramp.

A comprehensive review of radioactive pollution treatment of uranium mill tailings.

Natural uranium is a crucial resource for clean nuclear energy, which has brought significant economic and social benefits to humanity. However, the development and utilization of uranium resources have also resulted in the accumulation of vast amounts of uranium mill tailings (UMTs), which pose a potential threat to human health and the ecological environment. This paper reviews the research progress on UMTs treatment technologies, including cover disposal, solidification disposal, backfilling disposal, and bioremediation methods.

Radon attenuation characteristics of compacted soil layer for uranium mill tailings pond subjected to drying-wetting cycles.

Compacted soil layer (CSL) is generally designed for uranium mill tailings (UMTs) pond to form the radon seals, whereas it is usually affected by drying-wetting environmental conditions. To summarize the radon attenuation degradation performance of CSL subjected to drying-wetting cycles, an experiment with the application of meteorological data was developed. This paper focuses on the evolution of the soil apparent porosity, soil integrity and radon attenuation characteristics of CSL during continuous drying-wetting cycles.

Effect of simulated earthquake loading on radon exhalation from uranium tailings dam.

Uranium tailings sand will continuously release radon-222. When the external condition changes, the exhalation of radon will also change. Thus, radon is being recommended as a tracer for dam damage assessment.

STUDY ON THE INFLUENCE OF DRY DENSITY AND PARTICLE SIZE FRACTAL DISTRIBUTION ON THE RADON CONTROL PERFORMANCE OF OVERLYING SOIL IN URANIUM TAILINGS POND.

In order to explore the influence of dry density and particle size fractal distribution on the radon control performance of overlying soil in uranium tailings pond, overlying soil samples with different particle size fractal dimension and dry density were prepared for radon exhalation experiments. According to the principle of radon generation and diffusion, a set of radon measuring device was designed independently. In addition, the radon concentration on the surface of different overlying soil layers was measured by local static method, and the radon exhalation rate was further calculated.

Preparation and related properties of geopolymer solidified uranium tailings bodies with various fibers and fiber content.

Uranium tailing ponds are a potential major source of radioactive pollution. Solidification treatment can control the diffusion and migration of radioactive elements in uranium tailings to safeguard the surrounding ecological environment. A literature review and field investigation were conducted in this study prior to fabricating 11 solidified uranium tailing samples with different proportions of PVA fiber, basalt fiber, metakaolin, and fly ash, and the weight percentage of uranium tailings in the solidified body is 61.

Identification of sources with abnormal radon exhalation rates based on radon concentrations in underground environments.

When there is poor ventilation or an irregular radon exhalation rate in an underground environment, it is necessary to judge whether the radon concentration is abnormal. To protect personal safety and health from radon gas, it is necessary to track the location of an abnormal radon source and measure its release rate to formulate emergency control and eradication measures. However, in an underground environment, it is impossible to fully monitor the radon concentration at every location, and as a result, blind spots are present, making it difficult to obtain timely early warnings in the event of an abnormal radon exhalation rate.

Analysis of equivalent thickness of geological media for lab-scale study of radon exhalation.

Geological media are omnipresent in nature. Lab-scale tests are frequently employed in radon exhalation measurements for these media. Thus, it is critical to find the thickness of the medium at an experimental scale that is equivalent to the medium thickness in a real geological system.

Experimental study on permeability characteristics and radon exhalation law of overburden soil in uranium tailings pond.

The permeability characteristics of overburden soil have a significant effect on radon exhalation in uranium tailings pond. To understand this change, the effects of dry density, particle size range, and moisture content on the gas permeability and radon exhalation were studied by correlation analysis method. According to the mechanism of radon generation, the permeability characteristics of overburden, and the weather conditions, a theoretical model of radon exhalation was constructed and an experimental setup was designed.

Predictive analysis of shaft station radon concentrations in underground uranium mine: A case study.

This paper presented a method for predicting shaft station radon concentrations in a uranium mine of China through theoretical analysis, mathematical derivation and Monte-Carlo simulation. Based upon the queuing model for tramcars, the average waiting time of tramcars and average number of waiting tramcars were determined, which were further used in developing the predictive model for calculating shaft station radon concentrations. The results exhibit that the extent of variation of shaft station radon concentration in the case study mine is not significantly affected by the queuing process of tramcars, and is always within the allowable limit of 200 Bq m(-3).