Based on experimental research focused on enhancing the grade of natural uranium products, reducing impurity content, and controlling moisture levels, the key factors affecting product quality were analyzed. Corresponding measures were proposed, including increasing the uranium concentration of the qualified precipitation solution, elevating the precipitation temperature, improving the washing efficiency of the precipitate slurry, and optimizing the pressure and airflow during gas-pressurized filtration. Industrial application demonstrated that after implementing these measures, the uranium grade of the product was raised from 60% to 65%, with a maximum of 67.51%, moisture content was reduced from 25%-29% to 23%-24%; and the sulfate mass fraction was below 10%. These results fully comply with the new industry acceptance standards for natural uranium products specified by the customer.

The appearance quality of nuclear fuel pellets is closely associated with the operational safety and efficiency of nuclear reactors, and must exhibit high quality before being loaded into reactors. Currently, visual inspection by human operators is employed to control the quality of nuclear fuel pellets. However, manual inspection is highly subjective, prone to visual fatigue, carries risks of false and missed detections, and lacks the capability for quantitative defect analysis. To effectively detect surface defects of UO₂ nuclear fuel pellets, an automated inspection system based on machine vision has been designed. The system adopts a modular architecture: first, preprocessing the acquired pellet images; then, utilizing image segmentation techniques tailored to the surface characteristics of the pellets to extract defect regions; subsequently, applying connectivity analysis for defect examination; and finally, employing a combined approach of Support Vector Machine (SVM) classifier and Convolutional Neural Network (CNN) for defect classification, enabling automatic identification of pellet surface defects. The results demonstrate that the system achieves high detection accuracy and efficiency, meeting the requirements of industrial automated inspection.

Addressing the persistent challenge that general safety regulations are inadequate for metal mines employing specialized processes such as in-situ leaching, this study focuses on China's dominant in-situ leaching uranium mines and proposes a safety governance framework termed "three-layer decoupling and bidirectional integration". This methodology systematically develops China's Safety Regulations for In-situ Leaching Uranium Mines and three sets of mandatory safety assessment templates by decoupling complex risks, process stages, and heterogeneous standards, and integrating on-site requirements with regulatory provisions. The innovations are reflected in: the first cross-industry transformation and process adaptation of safety standards from multiple fields such as geological exploration and chemical engineering pipelines; the use of numerical simulation technology to verify and optimize threshold values for key clauses concerning drilling stability and leakage diffusion; and the complete reconstruction of the safety assessment paradigm, establishing a "standard-evaluation" closed-loop management and control system deeply integrated with the regulations. The outcomes have been implemented as mandatory industry standards. Application data indicate that mine safety compliance inspection efficiency has improved by approximately 50%. The systematic construction method and the integrated "regulation-assessment-application" formed in this research provide a replicable solution for the safety governance of other metal mines using similar leaching processes.

Background values of groundwater are the core basis for groundwater environmental management in in-situ leaching uranium mine. Aiming at the characteristics of large sample size, strong discreteness and high spatial heterogeneity in background values monitoring of groundwater during the construction period of an in-situ leaching uranium mine, this paper established a background values determination method consisting of Grubbs outlier test, manual review, data distribution type judgment, and values range & mean calculation. A case study was carried out in mining area 1 # to obtain the background values and spatial distribution characteristics of groundwater characteristic factors. This method can effectively distinguish natural high concentration values from man-made abnormal values with objective and representative results. It can provide technical support for groundwater environmental management of in-situ leaching uranium mines and also serve as a technical reference for background values determination of similar uranium mines.

In view of the characteristics of complicated types, high salt content and strong matrix effect of associated radioactive solid wastes, and there is no relevant standard method for analyzing radionuclides in associated radioactive solid wastes. Taking molybdenum ore slag, zirconium ore slag and rare earth slag as the measurement objects, the chemical components in the samples were measured by X-ray fluorescence spectrometer, and the simulated efficiency calibration was carried out by combining with the passive efficiency calibration software. The spectrum was measured by gamma spectrometer, and the gamma spectrometry method for the analysis of radioactive nuclides in associated radioactive solid waste was established. The experimental results show that the rare earth waste residue, zirconium waste residue and background matrix samples are uniformly mixed at the ratio of 3∶7 (30 g∶70 g) and 1∶4 (20 g∶80 g), and then put into the ϕ 75 mm× 20 mm sample box for gamma spectrometry measurement. The measurement dead time accounts for 9% and the correction error of self absorption factor is less than 5%; The absolute value of the relative error is less than 5%; The maximum deviation between the passive efficiency scale and the active efficiency scale is 4.74%; When ²³⁸U is measured with 92.6 keV full energy peak, the deviation of the measured results after the interference peak correction meets the requirement of less than 30%. Compared with other methods, the relative deviations of ²³⁸U, ²³²Th and ²²⁶Ra are 1.40%-5.03%, 0.59%-6.13% and 2.30%-3.85%, respectively. When the gamma spectrometer is used to measure the associated radioactive solid wastes, this method optimizes the sample loading quality, reduces the influence of sample self absorption, and does not need to match the solid waste standard sample with the same matrix, and the measurement result is reliable. The results provide a feasible analytical scheme for peer laboratories and technical support for the formulation of relevant industry standards.

This study investigated typical enterprises engaged in the integrated beneficiation and smelting of monazite, with a focus on characterizing the behavior of thorium-232 throughout the production chain. Through systematic analysis of activity concentrations in various raw materials and products from different manufacturers, the pathways and final distribution of thorium-232 across the entire technological process were traced. Workplace monitoring of thoron concentrations was carried out to assess inhalation hazards, collectively revealing the distinct migration and enrichment patterns of thorium-232 and its associated radiological exposure risks. Through the analysis of the chemical composition in monazite ore, it is found that the REO content is the key factor influencing the activity concentration of thorium-232. The monazite dressing process primarily involves stages such as shaking table gravity separation, drying, and electromagnetic separation, while the smelting process includes magnetic separation, alkali decomposition, and hydrochloric acid preferential dissolution. Thorium-232 exhibits a pronounced tendency for selective enrichment within these sequences. Comprehensive data on chemical composition and radionuclide activity from multiple enterprises in Hainan Province demonstrate that about 92.15% of thorium-232 is concentrated into the monazite product during electromagnetic separation. Further analysis based on material chemistry and activity measurements from a smelting enterprise in Hunan Province indicates that about 96.56% of the thorium-232 is subsequently transferred and further enriched in the residue generated from the hydrochloric acid preferential dissolution stage. It is noteworthy that emissions of thorium-232 in waste gases and process waters throughout both dressing and smelting operations are negligible relative to the total inventory.

Intermediate and low level radioactive waste accounts for the vast majority of the volume in nuclear energy development and application, but has relatively low radioactivity. Its solidification treatment is a key process for ensuring environmental and public health safety. This research deeply investigated the core characteristics of intermediate and low level radioactive waste, including complex nuclide composition, associated harmful substances, and large production volume with wide distribution. It also analyzed mainstream solidification technologies, focusing on cement solidification and bitumen solidification. The principles, technical features, performance parameters, research progress, and limitations of cement solidification were elaborated. The advantages and disadvantages of bitumen solidification, as well as its domestic and international research progress and key performance indicators, were analyzed. In response to challenges such as the complexity of waste composition, stringent requirements for solidified waste forms, cost and environmental control pressures, and updated regulatory standards, future LILW solidification technologies will focus on the development of novel solidification materials, innovative solidification processes, waste minimization and resource utilization, deep integration of intelligence and automation, and strengthen international cooperation and standardization. These efforts aim to achieve more efficient, economical, environmentally friendly, and safe solutions, providing strong support for the sustainable development of nuclear energy.

Based on the Second National Census of Pollution Sources, China has successively issued a series of policy documents on radiation environmental management for associated radioactive minerals. Radiation environmental management of associated radioactive minerals have been gradually standardized, though they remain to be further clarified and refined. This study analyzes the existing regulatory requirements and the current management status. It identifies issues in areas such as industry directory management, enterprise directory management, environmental impact assessment, the storage and disposal of solid waste in the sector of associated radioactive minerals. Grounded in practices and evolving management trends, this study proposes the following recommendations: adjusting the regulatory targets in the industry directory, establishing a dynamic management mechanism for enterprise directory, clarifying the authorities for environmental impact assessment approvals, and standardizing the requirements for solid waste storage and disposal.

Aiming at the water quality characteristics of low uranium concentration, high sulfate and high suspended solids in the seepage water of a decommissioned uranium mine in southern China, as well as the problems of unstable treatment effect, easy saturation and hardening of resin, and high operation and maintenance costs in the original resin adsorption uranium removal process, combined with the seasonal dynamic change law of uranium occurrence state under the background of the mine's karst landform, the analysis of seepage water quality characteristics and the optimization of treatment process were carried out. On the basis of finding out the cyclic mode of uranium "activation and migration in rainy season, local enrichment in dry season" and the difference of occurrence states in winter and summer, a seasonal combined treatment scheme of iron-based permeable reactive barrier (PRB) was proposed, and the process flow design, engineering facility planning and seasonal process parameter optimization were completed. The designed treatment capacity of the project is 400 m³/d, which can adapt to the seasonal fluctuation characteristics of the seepage water volume and uranium occurrence form of the mine, with an expected operation cycle of 10 years, and the materials can be recycled after regeneration. The application results show that the process has a significant removal efficiency for radioactive pollutants such as natural uranium, ²²⁶Ra, ²¹⁰Pb and ²¹⁰Po, the effluent water quality meets the standard stably for a long time, which can provide technical reference and engineering demonstration for the seepage water treatment of similar decommissioned uranium mines in karst areas.

To address the issues of low efficiency and high error rates associated with traditional manual methods for converting coordinate formats in the mineral resources national survey database, two conversion approaches and program algorithms are proposed: First, a forward conversion that transforms coordinate strings of mining areas (mines) in the database into coordinate pair text files; Second, a reverse conversion that transforms coordinate pair text files back into coordinate strings of mining areas (mines) in the database. These methods can provide data that meet format requirements for coordinate system conversion of mining areas (mines) in the database, and enable rapid rewriting of coordinate values and database updates after coordinate system conversion, thereby effectively enhancing the automation level of coordinate data processing and data management efficiency.