A method for simultaneous determination of As and Hg in uranium ore by hydride generation atomic fluorescence spectrometer was established, and the effects of digestion temperature, digestion time, medium system, KBH₄ concentration, and uranium content on the detection results were investigated. The results show that the optimal conditions for this method are to dissolve uranium ore with (1+1) aqua regia for 60 minutes at 125 ℃, (5+95)HCl as the medium and 2.0% KBH₄ solution as the reducing agent. The detection limits of this method are 0.006 μg/g (for As) and 0.001 μg/g (for Hg), with relative standard deviations of 2.46% (for As) and 4.22% (for Hg), and recovery rates of 98%~103%(for As) and 97%~106% (for Hg). This method has high accuracy and precision, and can meet the requirements for the determination of As and Hg in uranium ore.

Radioactive decontamination is an important technical means to ensure the sustainable development of nuclear industry. Radioactive decontamination is not only related to the comprehensive cost of operating and managing facilities such as nuclear power plants, and the development of radioactive mineral resources, but also related to personnel safety and social environmental safety, and should be given sufficient attention. On the basis of summarizing various radioactive decontamination technologies commonly used in the process of decommissioning and maintenance of domestic nuclear facilities, the application conditions, advantages and disadvantages of physical decontamination, chemical decontamination, electro oxidation decontamination, microbial decontamination and smelting decontamination technologies are analyzed, and the technical pain points and development direction of decontamination technology is proposed.

In order to enhance the quality of uranium dioxide products, a comparison and analysis was conducted on the bulk density of uranium dioxide products in both the new and old uranium purification production lines. It was observed that the bulk density of products in the old production line exceeded that of products in the new line. The primary factor contributing to this difference was identified as significant fluctuations in crystallizing agent concentration of the new production line, resulting in inadequate crystallization effects for uranyl ammonium tricarbonate and smaller crystal sizes, consequently impacting crystal calcination effectiveness. As a result, there was a decrease in uranium dioxide product density and overall product quality. To address this issue, several measures were implemented,such as merging ammonium carbonate preparation positions between the new and old production lines, unifying and localizing crystallizing agent supply, enriching recovered ammonium carbonate solution, and flushing pipeline with steam flushing. These actions successfully resolved fluctuation problems related to crystallization effects within the new production line, leading to an average increase of 5.71% in bulk density of uranium dioxide products as well as an average net weight per barrel increase by 4.73%. Consequently, notable improvements were achieved regarding product quality for uranium dioxide.

Part of the waste residue generated during the development and utilization of rare earth resources belongs to the associated radioactive solid waste. The safe and effective disposal of this type of waste residue is an urgent problem that needs to be solved in the current development of the rare earth industry. By the method of investigation and analysis, based on the types and sources of rare earths, statistics were conducted on the types, yields and radioactive nuclide activity levels of waste generated during the mining and selection process. Combined with the development plan of the rare earth industry, the stock and increment of rare earth waste in typical provinces(autonomous regions) were preliminarily estimated. And the current status and existing problems of the treatment and disposal of rare earth associated radioactive waste residue were sorted out. On this basis, a strategy for regional landfill disposal is proposed: it is recommended to implement a 7+x model nationwide, and to build rare earth waste residue warehouses in major rare earth provinces(autonomous regions), with reference to the model of Baotou in Inner Mongolia, to collect and dispose of rare earth associated radioactive waste residues in the provinces(autonomous regions). Based on the estimated amount and increment of waste residues, suggestions for the scale of rare earth waste residue disposal in each province(autonomous region) are provided.

Clay is a crucial component of the coexisting radioactive waste cover layer. The investigation of its shielding performance is of significant importance. In this study, the effects of clay type, clay moisture content, emulsion type, clay+geomembrane on radon shielding were studied by means of self-designed experimental apparatus. The results show that montmorillonite stands out as a clay type with relatively superior shielding capabilities, montmorillonite with 25% moisture surpassed other moisture levels, montmorillonite combining either polyurethane emulsion or geomembranes can yield favorable shielding effects. This research provides essential data and theoretical guidance for the utilization of clay in radon shielding.

Sandstone-type uranium deposits point has been found in Chepaizi area of the western Junggar Basin, among which the Neogene Shawan Formation uranium mineralization is widely distributed. The uranium metallogenic potential and prospecting direction in this area have been studied, but the uranium metallogenic conditions are not clear. The formation of sandstone-type uranium deposits is the result of water-rock interaction. It is important to study the relationship between hydrogeological conditions and uranium mineralization. According to the paleohydrogeological evolution, the hydrodynamic conditions of uranium mineralization were analyzed. The hydrochemical components were used to analyze the hydrogeochemical characteristics of groundwater. The uranium exploration and oil data were used to analyze the geochemical characteristics of rocks, sand body characteristics, sedimentary facies characteristics, development characteristics of ancient interlayer oxidation zones, and oil-gas transformation. The differences in the hydrogeological conditions of uranium mineralization in the three sand groups of the first member of the Shawan Formation and the favorable areas for uranium mineralization were revealed. The research shows that the 128 group has the most favorable hydrogeological conditions for uranium enrichment where is the intersection of the underwater distributary channel of the fan delta front and the braided river delta front and on both sides of the fault zone. The thickness of the sand body is stable, the connectivity is good, the uranium mineralization lasts for a long time. The uranium metallogenic condition of Tachakou area and 126 group is less. The 3 sand group of Shawan Formation was the best, the 1 sand group was the second, and the 2 sand group was the worst.

This study conducted γ-radiation cumulative dose monitoring and instantaneous monitoring of γ-radiation air absorption dose rates at 31 monitoring locations around the Fangchenggang nuclear power plant, analyzing the radiation level monitoring results to grasp the long-term changes in terrestrial radiation levels around the nuclear power plant. The results show that from 2018 to 2023, the environmental γ-radiation cumulative dose rate monitoring values around the Fangchenggang nuclear power plant ranged from 62.5 to 141.3 nGy/h, with an average value of 99.1 nGy/h; the instantaneous dose rates ranged from 55.0 to 119.5 nGy/h, with an average value of 93.7 nGy/h. The terrestrial environmental radiation levels around the plant remained consistent before and after the commercial operation of its three units, with both γ-radiation cumulative dose rates and instantaneous dose rates maintained at normal levels, indicating that the emission of airborne effluents during the operation of the nuclear power did not impact the radiation levels in the surrounding environment. There was significant variation in the γ-radiation cumulative dose rates at different monitoring points, with a tendency for higher levels in winter and lower in summer, suggesting that γ-radiation cumulative dose rates are greatly influenced by environmental factors.

The fine management model was introduced in a “CO₂ + O₂” in-situ leaching uranium mine in Inner Mongolia, and the processes of adsorption, leaching, acidification and precipitation which affect the quality of production were carefully managed. The preparation of eluent was optimized from “settling mother liquor + sodium bicarbonate + hydrochloric acid + sodium chloride” to“settling mother liquor + sodium bicarbonite + water”, the pH of eluent was maintained at 9.5 ~ 10.0, and reducing the accumulation of chloride ion in the system. The peak mass concentration of uranium in the eluate was increased and maintained at 80~130 g/L. The amount of hydrochloric acid added in the acidification process is automatically controlled, the pH is accurately controlled in 4.5~4.6, and the ratio of carbon to uranium in the qualified liquid is further reduced. Adjust the flow rate of leachate to keep the average mass concentration of uranium in 30~70 g/L, to reduce the influence of mass concentration of uranium on product quality. Control slurry precipitation time, to improve slurry pressure filtration effect. After the optimization of production parameters, the moisture content of the product decreased by 8.50%, the uranium content increased by 2.88%, and the product quality was improved as a whole.

The ore grade of the Rossing Uranium Mine in Namibia is low and the processing capacity is large. The mined ore is mixed with some waste rocks, and the grinding and leaching costs are high. To solve this problem, the distribution patterns of ore particle size and uranium grade were studied, the radioactivity visibility of representative ore samples was calculated, the radioactive selectivity curve was drawn, and the theoretical sorting index based on the cut-off grade was determined. The theoretical sorting indicators are: when the cut-off grade is 0.01%, the raw ore uranium grade is 0.032%, the concentrate uranium grade is 0.047%, the tailings yield is 33.95%, the tailings uranium grade is 0.002 8%, and the total recovery rate is 96.37%. The results show that radioactive beneficiation has a certain effect and the ore selectivity is high. It is mainly suitable for tailing of coarse-grained and extremely low-grade ores. The radioactivity visibility can be used as the theoretical basis for radioactive beneficiation of Rossing Uranium Mine.

In-situ leaching uranium technology is an important means of sandstone type uranium mining in China. In-situ leaching drilling is the only channel connecting the ground to the underground ore layer, which plays an important role in uranium mining. The construction efficiency of in-situ leaching drilling affects the construction and development of the entire uranium mine. Taking a certain uranium mine as the research object, the efficiency and existing problems of in-situ leaching drilling construction from 2019 to 2020 were statistically analyzed. The results show that compared with core drilling machines, water well drilling machines have significant advantages in construction. The configuration of mud pumps, drilling depth, logistics management, and support all have an impact on the efficiency of drilling construction. Improvement suggestions have been proposed for the factors affecting construction efficiency, in order to achieve the goal of reducing costs and increasing efficiency.