Uranium is an important strategic resource as well as a heavy metal element with chemical and radioactive toxicity. Currently, the efficient remediation of uranium in groundwater from uranium mines remains a huge challenge for environmental protection and ecological security. In this study, sodium tripolyphosphate was used to modify nano zero-valent iron (nZVI), successfully preparing STPP-nZVI. The effects of solution pH, STPP-nZVI dosage, temperature, time, U(VI) concentration, and interfering ions on the STPP-nZVI-mediated remediation of U(VI) in groundwater were investigated. FTIR, SEM-Mapping, and XPS were employed to explore the mechanism underlying STPP-nZVI’s remediation of uranium-contaminated groundwater. The results indicate that STPP-nZVI is suitable for treating weakly acidic and alkaline uranium-contaminated groundwater. At a pH of 5.0, the maximum adsorption capacity of STPP-nZVI for U(VI) reached 102.72 mg/g, with U(VI) adsorption occurring as a spontaneous endothermic process. The removal of uranium by STPP-nZVI is primarily attributed to adsorption and reduction. STPP-nZVI materials demonstrate promising application prospects for treating weakly acidic and alkaline uranium-contaminated groundwater.

This paper summarized the sedimentary facies types and characteristics of the Upper Cretaceous Yaojia Formation in Baiquan area, Songliao Basin. It is considered that the Yaojia Formation in Baiquan area can be divided into upper and lower members. The upper member of Yaojia Formation has meander river facies and delta facies, while the lower member has braided river facies and delta facies, and further be divided into 6 subfacies and 10 sedimentary microfacies. The braided river facies sand body of the lower member of Yaojia Formation has large thickness, good uranium anomaly has been found, which has good uranium metallogenic potential, and is a favorable area for uranium prospecting in the future.

The well washing process of in-situ leaching uranium mine is an important means to increase the amount of drilling water. However, a large amount of impurities such as sediment in the well washing wastewater cause the bag filter and adsorption tower pressure to rise, which indirectly affects the production progress. Based on the principle of centrifugal force, a sand removal device for well washing wastewater was developed and applied in a certain in-situ leaching uranium mine. The results show that it can reduce the pressure of bag filter and adsorption tower, reduce the frequency of filter bag replacement, increase the adsorption water and increase production capacity. The sand removal device of the well washing wastewater has a certain popularization value in the drilling and well washing technology of in-situ leaching uranium mine.

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.

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.

Fengcheng paigeite deposit is a large scale multi-metal deposit containing boron, iron and uranium, which is developed by open-pit mining, following by beneficiation (gravity separation, magnetic separation, and flotation) and hydrometallurgical treatment to obtain iron concentrate, sodium borate, and diuranate as products. In this process, several kinds of solid waste are produced such as mining waste rock, beneficiation tailing, and leached uranium tailing. Through detailed investigation of the radioactive characteristics of product and solid waste in the full process, it is indicated that iron concentrate and sodium borate meet their radioactivity quality standard. Mining waste rocks, beneficiation tailing, gravel and coarse sand produced by crushing of ore, and boron mud can be treated and disposed as ordinary solid waste other than radioactive waste. Gravel and coarse sand can be used as building materials. Boron mud is used to produce sub-nanomater silica stone without any limitation related to radioactivity, in case of the boron mud addition not exceeding 50%. Leached uranium tailing should be disposed as extremely low level radioactive waste.

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.

The high rates of submersible pump damage due to pump shaft fracture and pump body corrosion have been studied. By conducting theoretical calculations and ANSYS numerical simulations, the mechanical properties such as strength and stiffness of hexagonal and cylindrical shaft structures were compared. Field comparison tests on the corrosion resistance of 304, 316L, and 904 stainless steel materials were also carried out. The results indicate that under the same load and equivalent diameter conditions, the shear stress on the cross-section of the cylindrical axis is 64.95% of the hexagonal axis, and the torsion angle is only 56.25% of the hexagonal axis torsion angle; the simulation results show that the maximum circumferential deformation of the cylindrical shaft coupling is 68.4% of the maximum circumferential deformation of the hexagonal prism shaft, the cylindrical shaft structure exhibits better torsional performance. While 904 stainless steel has the best corrosion resistance, both 304 and 316L stainless steels demonstrate similar corrosion resistance to acidic media. Considering corrosion resistance margins and manufacturing costs, it is recommended to use a cylindrical pump shaft structure and continue using 316L stainless steel as the main material in the development of submersible pumps for uranium mining.