Hydrogeological conditions are crucial for the site selection and long-term safety assessment of high-level radioactive waste (HLW) disposal repositories. This study focuses on the groundwater circulation characteristics of Xinchang preselected site and its southern periphery of the Beishan area for HLW disposal. A comprehensive approach employing multiple environmental isotopes, hydrodynamics, and numerical modelling was used to investigate groundwater circulation within the study area. Results indicated that groundwater in shallow loose sediments exhibited relatively rapid renewal rates, with an average age generally less than 30 years. The apparent ¹⁴C age of deep bedrock groundwater generally exceeding 10 ka within the underground research laboratory (URL) site. There was no evidence of contributions from deep crustal or mantle sources to groundwater within the region. Within the Xinchang site, the groundwater head shows pronounced vertical stratification, with a higher hydraulic head in shallow zones than in deeper ones. Groundwater in boreholes distant from the gully shows weak hydraulic connectivity with precipitation, and the groundwater level often exhibits periodic fluctuations. The groundwater flow systems can be categorized into three types: regional, intermediate, and local. The local flow system was the most active, accounting for over 80 % of the total flux. These characteristics showed that the hydrogeological conditions in the study area were favorable for the geological disposal of HLW.

The Ordos basin is the second largest energy basins in China，and several large uranium ore deposits have been discovered. The upper member of Lower Cretaceous Huanhe formation in the basin is the main prospecting horizon. In this paper，the uranium mineralization characteristics and metallogenic mechanism of Lower Cretaceous Huanhe formation in northern Ordos basin are studied by means of geological characteristics，altered mineral association，rock geochemistry and the metallogenic model is established. The three superimposed system domains of Lower Cretaceous Huanhe formation formed a fine-coarse-fine stratigraphic structure，which provided a foundation for the migration of uranium ore-forming fluids in the later period. In the early stage of mineralization，the scale of the oxidation zone was limited，and the main alteration minerals were hematite，limonite，pyrite，chalcopyrite，sphalerite，calcite and coffinite，etc. The metallogenic environment were of strong reducing capacity，the ore-forming fluid were strongly alkaline，and intense water-rock interaction occured. In the middle and late stage of mineralization，the oxidation zone advanced into the basin，a strong REDOX reaction developed ，the primary ore zone and reduction zone were formed，and the metallogenic environment maintained the early strong reducibility. The main altered minerals in this period were hematite，limonite，pyrite，montmorillonite，chlorite and uranite. With the mixing of ore-forming fluids，ore-forming fluids gradually turn to weak alkaline，uranyl silicate ions decomposed，and a large amount of uranite was formed.

Zoujiashan uranium deposit is located in the west of Xiangshan ore field ，which is the biggest volcanic-type uranium ore deposits in China. The exploration in recent years have found some uranium ore bodies. Based on the finished achievement of the research and exploration practice, this papers summarized the location of uranium ore bodies in Zoujiashan as the 6 positions：1）fractures zones in main fault；2）steep parts created by volcanic collapse structures；3）the junction of faults；4）secondary fracture zone in the side of main fault；5）clamping parts of parallel faults；6）the junction of volcanic collapse structures，faults，interface of different rock. We proposed three favorable location for the future exploration, they are the stable fissure-dense sector of zone 2 in hanging the wall of F₆ main faults，the secondary fissure sector of Zone 1 beside the F₂ fault，and a “waterfall”-like interface between different rock strata in zone 4. The first and second sector should preliminary explore shallow；the third one may explore -250 m elevation or deeper. The proposed sector provide not ideas for exploring uranium deposit in Zoujiashan area，but also the resource for the mining enterprises.

The southern section of Zone No. 9 in Mianhuakeng deposit is located in the middle of the Zhuguang pluton,which is a rich in uranium. The fault zone has undergone multiple tectonic and hydrothermal action ，forming the favorable space for uranium mineralization and storage. Through secondary development and utilization of data from previous exploration projects，this paper analyzes the change patterns of the ore bodies at different elevations in the southern section of Zone 9 by the statistics on grade and thickness. The results indicate that the ore body trend to be rich in the depth but remain stable in thickness on the whole with local widening. The occurring frequency of moderate and high-grade ore segments are increasing in the deep, which may be caused by the reduction environment in the deep. This understanding provides clues and basis for the next uranium predicting and prospecting.

Dalishu uranium deposit is a carbonate rock type uranium deposit located at the Lukan fault hanging wall in the southeast limb of Xiongwu anticline. Researches on this uranium deposits are still seldom reported. Based on the field geological survey and collection of uranium ore samples in trenches and boreholes, this paper conducted a study on mineralogy，geochemistry，and genesis of the deposit. The study show that the ore body is controlled by the northeast-trending faults and the secondary Si-Ca structural planes and closely related to organic matters. The main uranium minerals in the ore are pitchblende and uraninite，and the uraninite minerals,which are closely associated with pyrite and “black”organic matters. The trace elements such as V，Cr，Co，Ni，Cu，Zn，and Mo are enriched in the ore and the wall rocks.The rare earth element distribution pattern is“right-inclined” with the enrichment of LREE and negative δEu anomaly，indicating a certain genetic relationship with the Cambrian black rock series. It believed that the ore-forming materials maybe come from the Cambrian Niutitang and Laoba formation，the deposit was formed by deep hydrothermal action which extracted the uranium from the Cambrian basement ore-forming materials and carried to favorable areas under the orogenic background of Himalayan period.

Under the background of developing digital economy，the digital transformation of uranium exploration is facing structural imbalances，manifested as core contradictions such as the difficulty in integrating multi-source data，technology fragmentation，and the disconnection between data flow and business flow. This paper focused on the application requirements of digital exploration technology，proposes an information architecture model of “business logic reconstruction-data asset governance-technology middle platform empowerment”as a trinity，and designed the overall blueprint of the “54321 Project”，covering five types of application systems，four supporting systems，three platforms，two types of centers and one full-process data chain, so as to solve the problem of the broken chain of“data-knowledge-decision”. The closed-loop optimization of business flow，data flow and decision-making flow was achieved through a four-dimensional collaborative architecture system. Through the data middle platform and cloud platform，the management domain and the production domain are deeply coupled. A technical support system centered on the integration and application of multi-source data is constructed，forming an integrated data ecosystem of “mining-storage-treatment-utilization”，providing a replicable theoretical framework and practical paradigm for the digital transformation of uranium ore exploration.

In seismic exploration，high-resolution seismic reflection imaging data volumes are critical tools for achieving fine identification of thin sandstone bodies and fault structures in sedimentary basins. However，actual seismic imaging profiles often face the loss of low- and high-frequency signals，leading to low seismic imaging resolution and ineffective identification of oil，gas，uranium，coal，and other mineral resources. In signal processing，integral and differential algorithms of effective signals respectively reflect their low- and high-frequency components. Based on this principle，this paper proposes an interpretative high-resolution processing method using multi-level fractional calculus. By separately calculating different fractional-order components of effective signals，the missing low- and high-frequency components in seismic imaging profiles are obtained. Through the introduction of multivariate Gaussian theory，Bayesian theory，and statistical inversion to improve the solving process of weighting coefficients，a broadband high-resolution seismic imaging profile is established. Compared with traditional calculus-based high-resolution processing methods，this method effectively enhances the accuracy of weighting coefficient determination and avoids the impact of calculation errors on precision. Processing results from both onshore and offshore actual data demonstrate that the proposed method significantly improves the resolution and frequency bandwidth of seismic data，thereby enhancing high-resolution identification of sand bodies and related structures.

In order to make the distribution of lateral physical properties and layer parameters between adjacent measuring points smoother and more continuous and reduce the limitations of a single geophysical inversion method，a pseudo-two-dimensional lateral constrained joint inversion study of controlled source audio frequency magnetotelluric method (CSAMT) and micro-motion spectrum ratio method was carried out. The microtremor data is numerically simulated using the spectral ratio method，combined with the CSAMT-based limited memory BFGS (L-BFGS) inversion algorithm，introducing the lateral constraint theory，and adding the cross-gradient function to achieve the mutual coupling of two different physical parameters. A set of quasi-two-dimensional lateral constraint joint inversion algorithms was developed，and the accuracy and effectiveness of the algorithms were verified through two sets of theoretical models. Meanwhile，the inversion algorithm is used to invert the measured data in Yanqing，Beijing. The results show that there is a good correspondence between the abrupt interface morphology of resistivity and shear wave velocity，which proves the practical value of the laterally constrained joint inversion algorithm.

High-quality field seismic data are fundamental to the refined processing of seismic signals and the accurate interpretation of geological information. A scientifically designed observation system is essential to ensure data quality and imaging effectiveness. In complex geological settings，traditional acquisition systems are prone to insufficient energy coverage and imaging shadow zones，which hinder the identification of reflection signals and the detailed delineation of target structures. To enhance seismic imaging performance under such conditions，this study conducts a systematic investigation into acquisition parameter optimization for observation systems in structurally complex areas，based on an illumination analysis approach using the one-way wave equation. Forward illumination analysis is first employed to optimize the layout of sources and receivers, thereby improving energy coverage over target horizons. Subsequently，reverse illumination analysis is used to refine shot point densification，receiver array length，and channel spacing，aiming to enhance energy acquisition and wavefield coverage. A two-dimensional geological model is constructed，and forward modeling is performed to quantitatively compare the illumination energy distribution before and after optimization，leading to the determination of acquisition parameters that meet imaging requirements. Results show that the optimized observation system effectively reduces imaging shadows in complex structural zones，improves profile continuity and reflection energy response，and exhibits strong adaptability and engineering feasibility. The proposed optimization workflow has been applied and validated in an actual survey area，demonstrating consistent improvements in imaging performance. This work confirmed the practical value of illumination-based analysis in the acquisition design for complex geological conditions and established a parameter configuration methodology suitable for fault-intensive zones and sand body development areas，which will provide a replicable design reference and technical path for future seismic exploration.

To address the applicability challenges of geophysical water exploration methods in the Carboniferous Huangjin formation of carbonaceous-argillaceous limestone characterized by uneven development of dissolution fissure，complex hydraulic connectivity of argillaceous shale interlayers，concealed groundwater occurrence conditions，scant water resources，and improve the success rate of water well drilling, This paper adopts high-density resistivity and Audio-frequency Magnetotelluric Sounding (AMT) methods to detect low-resistivity anomalies in an area of Shaoshui town，Guilin. By applying the induced polarization (IP) secondary time difference method to analyze and delineate water-induced anomalies within these low-resistivity zones. the spatial distribution and occurrence characteristics of groundwater were identified. Results indicate that the AB/2 positions characterized by low-resistivity anomalies，positive induced polarization secondary time difference values with good continuity correspond to the actual aquifer locations. Meanwhile，areas with single-point values or values below 50 ms and poor continuity exhibit low water-bearing capacity.

CO₂ is the main component of non-condensable gas in high-temperature geothermal fluid and its existence still have important impact on geothermal development. Determining its content in high-temperature geothermal fluid is of great significance for geothermal development. The conventional sampling and testing analysis of CO₂ content determination has some drawbacks, such as insufficient sampling representativeness，cumbersome implementation process and high sampling cost. Based on the pressure-temperature measurement in the wellbore during discharge tests and two-phase flow calculation, this paper proposed a new method to determine CO₂ content in the geothermal reservoirs. This method only uses a large number of relatively reliable measured data of temperature and pressure, it has low cost, strong practicability and good reliability. This paper first describes the pressure-temperature measurement during discharge tests. Then constructs a model that solves the two-phase flow in the geothermal wellbore, which was verified by comparison with the commercial software WELLSIM, and determine CO₂ content by using both the wellbore pressure-temperature measurement and model calculation data. Finally, the method was tested and verified by using the measured data from Gulu geothermal field in Tibet and the Ziledaer geothermal field in Turkey, and the CO₂ contents in the geothermal reservoir were determined to be 1.1 % and 3.2 % respectively.

The rock fragmentation mechanism of worn disc cutters provides theoretical guidance for TBM cutter changing. To investigate the correlation between cutter force and penetration depth，evaluate rock fragmentation efficiency，and elucidate the fragmentation mechanism of single worn cutter in extremely hard rock conditions，different blade widths were utilized to represent different wear levels. This study employed sequential indentation tests using both a new cutter with blade width of 17 mm and worn cutters with different blade widths on Beishan granite specimens with dimension of 420 mm×400 mm×500 mm. The penetration process，force characteristics，rock fragmentation volume，and specific energy were systematically analyzed. The key findings include：1）Both new and worn cutters exhibited consistent rock failure phases - initial compaction followed by linear deformation，with intermittent force drops during single penetration, 2）During sequential penetrations with the same depth for the new cutter，both the maximum penetration force and the force growth rate in linear-deformation stage demonstrated an initial increase then decrease, 3）Worn cutters with larger blade widths required higher average force per unit penetration depth. For each kind of worn cutter，the force-depth ratio of each penetration showed fluctuating tendency during the whole sequential penetration process，confirming the cyclic process of energy accumulation，release and then re-accumulation, 4）Specific energy increased linearly with blade width while the penetration capability decreased correspondingly. The 18 mm-blade cutter exhibited optimal rock fragmentation efficiency and penetration performance in sequential penetration.

As the field verification standard for radioactive measuring instruments such as gamma loggers in uranium exploration work，radium sources have played a good role in controlling the metrological performance of the instruments. However，due to national security and environmental protection policies，the existing number of solid radium sources in China can hardly meet the increasing demand of uranium exploration workload，and there is an urgent need to carry out the development of alternative verification devices. It is planned to use natural uranium ore powder and other materials to develop verification devices to verify the radioactivity measuring instruments during the period. Based on the theory of γ radiation field，the relationship between the geometry of the verification device and the internal γ field was calculated，and it was experimentally verified that an annular column verification device with an internal bore diameter of 50 mm and an axial length of 600 mm can ensure that the center of the verification device has a saturated plateau area of 200 mm，leaving at least 100 mm redundancy for convenient detector placement. The internal irradiation volume rate is positively correlated with the thickness of the horizontally oriented ore layer before the saturation thickness is reached. The practical geometry of the γ logger verification device was determined by theoretical calculations，avoiding the waste of material and time in a large number of conservative designs.

Microwave plasma torch（MPT）is a new type of plasma excitation source developed by domestic research team. It is a soft ionization technology with atmospheric ionization characteristics and is mostly used for the analysis of organic matter. Compared with inductively coupled plasma（ICP）ionization sources，MPT has low ionization energy and is difficult to ionize the tested elements into metal ions，which limits its application in inorganic detection. In order to broaden the application range of MPT source，linear ion trap mass spectrometry（LTQ-MS）was used to establish a quantitative analysis method for zirconium，which was applied to environmental monitoring. The zirconium solution was introduced into the MPT-LTQ-MS experimental device，and the aerosol was produced by pneumatic atomization. After drying by concentrated sulfuric acid，the dried aerosol formed anions in the plasma flame generated by the microwave plasma moment，and was detected by LTQ-MS in the negative ion mode. The experimental results show that part of the excited zirconium ion can basically be confirmed to exist in the form of [ZrO(NO₃)₃]^-. This composite anion can be used as the characteristic signal to detect zirconium in water samples，and can be quantitatively analyzed by the characteristic spectral peak of multi-stage mass spectrometry. The characteristic signal of m/z 292 （⁹⁰Zr）showed a good linear correlation with the concentration of zirconium in the concentration range of 5~100 μg·L^-1(R²=0.998 8). The limit of detection (LOD) of the method was 2.6 μg·L^-1，and the precision (RSD) was better than 8.9 %. The content of zirconia in surface water was determined by MPT-LTQ-MS，ranging from 0.34 to 3.22 μg·L^-1，and the recovery of standard addition was 94 % to 105 %. The results show that MPT-LTQ-MS can be used as a simple method for the determination of zirconium，and can be used in environmental monitoring and drinking water testing.

To accurately measure the oxidation-reduction potential of uranium ore geological samples, this study try to explore a better measurement method and experimental conditions by comparing and analyzing the application effects of the acidic potassium dichromate method and the alkaline potassium permanganate method in the measurement of the oxidation-reduction potential of uranium ore geological samples. The potential drop method was used to systematically conduct a multi-dimensional comparison between the acidic potassium dichromate method and the alkaline potassium permanganate method. The aspects of comparison included solution stability, optimal solution concentration, sample soaking time，solid - liquid ratio, and electrode equilibrium time. The sample soaking time and electrode equilibrium time of the alkaline potassium permanganate method are shorter than those of the acidic potassium dichromate method, allowing it to reach a stable and reliable potential value more quickly. For strongly reducing samples，the ΔEh value obtained by the acidic potassium dichromate method is larger. However, the evaluation conclusions of the two methods regarding the reduction ability of the samples are consistent. Nevertheless, the precision of the alkaline potassium permanganate method is better.The optimal experimental conditions for the alkaline potassium permanganate method are as follows: a concentration of 0.03 mol∙L^-1, a sample soaking time of 1.5 h，a solid-liquid ratio of 1:25, an electrode equilibrium time of 5 min, a reaction medium of 0.2 % potassium hydroxide solution, and a temperature of (25±1) °C. The ΔEh value measured by this method is basically consistent with the judgment results of the oxidation - reduction environment by the oxidation coefficient method (Fe²⁺/Fe³⁺), and is also basically consistent with the color of the samples.Based on comprehensive experimental indicators, the overall performance of the alkaline potassium permanganate method is superior to that of the acidic potassium dichromate method in the measurement of the oxidation - reduction potential of uranium ore geological samples. By adopting the optimal experimental conditions, the accurate measurement of the oxidation - reduction potential of uranium geological samples is achieved, providing reliable technical support for uranium ore geological research.

This study monitored the activity concentrations of radionuclides in seepage water from a decommissioned uranium tailings pond，analyzed the temporal trends of radionuclide concentrations in seepage water from 2020 to 2024，and investigated the correlations between radionuclides in seepage water and monitoring well water to evaluate the radiological impact of seepage on surrounding groundwater. The results showed that the seepage water contained uranium at concentrations ranging from 15.1 to 397 μg·L^-1，²²⁶Ra from 0.008 to 0.176 Bq·L^-1，²¹⁰Pb from 0.007 to 0.172 Bq·L^-1，and ²¹⁰Po from 0.004 to 0.021 Bq·L^-1，levels of ²²⁶Ra，²¹⁰Pb，and ²¹⁰Po are all below regulatory limits. In monitoring well water，uranium concentrations ranged from 0.21 to 2.98 μg·L^-1，²²⁶Ra from 0.006 to 0.023 Bq·L^-1，²¹⁰Pb from 0.004 to 0.131 Bq·L^-1，and ²¹⁰Po from 0.002 to 0.011 Bq·L^-1，all consistent with local background levels. Analysis using the Mann-Kendall test revealed no significant temporal trends for uranium and ²²⁶Ra in seepage water，while ²¹⁰Pb and ²¹⁰Po concentrations exhibited declining trends and become stable. According to the evaluation results of Spearman correlation coefficient, the Spearman correlation coefficient ρ_s for uranium，²²⁶Ra，²¹⁰Pb，and ²¹⁰Po in the seepage water and monitoring well water were 0.314 3，0.074 4，0.939 5，and 0.460 5，respectively. Significant positive correlations were observed between ²¹⁰Pb and ²¹⁰Po in monitoring well water and their counterparts in seepage water. These findings provided critical data and regulatory guidance for authorities and enterprises to strengthen radiation environmental monitoring and implement targeted management strategies, thereby mitigating potential risks to groundwater safety around uranium tailings facilities.

In order to understand the current situation of the air absorption dose rate level from terrestrial γ-radiation in Yinchuan, master the distribution pattern of surface γ-radiation，evaluate the external exposure level of residents，gradually establish and improve the environmental radiation background database of the whole city of Yinchuan，Ningxia，and provide technical support for ensuring the health and safety of the public and the development of urban construction，and provide a basis for government decision-making, Evenly measuring grid method was used to cover the measurement area of the air absorption dose rate of surface γ-radiation in Yinchuan city. The dose rate levels of different administrative regions，different environmental conditions，different soils and materials in Yinchuan city were collected and summarized, the effective dose received by residents was estimated. The survey results indicate that the average terrestrial gamma radiation absorbed dose rate in Yinchuan (after deducting cosmic ray contributions) is 48.67 nGy·h^-1，primarily attributed to ⁴⁰K. This value closely aligns with the regional average in Ningxia Hui Autonomous Region but is significantly lower than the national average. The resultant annual effective dose to the public is calculated as 0.30 mSv，which is lower than both the per capita annual dose from terrestrial radiation in China (0.46 mSv) and the outdoor gamma radiation dose in Ningxia (0.55 mSv).

The current research on quantitative assessment of nuclear emergency response plans suffers from the lack of a systematic assessment framework and methodological limitations，which are manifested in the fragmentation of assessment dimensions，weak relevance of the indicators，and significant subjective cognitive bias，resulting in serious constraints on the comparability and reproducibility of the results of the assessment. The current assessment situation is difficult to meet the urgent needs of nuclear emergency rescue teams for the continuous improvement of plan quality， especially the lack of effective quantitative tools for key performance indicators，such as the timeliness of plan response and the rationality of resource allocation. To address the kennel problems of discrete index system and strength the subjectivity in the evaluation of nuclear emergency rescue teams’emergency plans，this study constructs a multi-level quantitative assessment system for emergency plan quality based on the theory of complex adaptive systems，and the fusion of heterogeneous data from multiple sources and optimisation strategy of model integration. At the level of theoretical construction，this study firstly deconstructs the professional characteristics and operation mechanism in the process of nuclear emergency plan preparation. Combined with the empirical data accumulated during the regular operation and maintenance of nuclear emergency rescue teams，a three-dimensional assessment framework was innovatively proposed. The framework systematically integrates the core assessment dimensions such as normative principles，structural integrity requirements and content coverage，forming a hierarchical assessment system oriented to continuous quality improvement. In terms of methodological innovation，this study adopted the deep coupling strategy of hierarchical analysis method (AHP) and fuzzy comprehensive evaluation method (FCE) to construct a hybrid assessment model with dynamic correction function. Through the structured indicator system design method，a stepwise evaluation system containing 6 first-level indicators (system architecture， response process，resource allocation，training and rehearsal，information management，and continuous improvement) and 23 second-level indicators (e.g.，completeness of command system，timeliness of emergency response，and rate of equipment configuration up to the standard，etc.) has been established. Among them，the AHP module completes the allocation of indicator weights by constructing a 1-9 scale judgement matrix，focusing on solving the problem of quantifying the structural relationship between multi-level indicators；while the FCE module applies the trapezoidal affiliation function to achieve the quantitative conversion of qualitative indicators，effectively reducing the bias of subjective judgement. The model validation process adopts a dual testing mechanism：the theoretical level is to test the structural validity of the indicator system through expert argumentation; the practical level is to select a national nuclear emergency rescue team to carry out empirical research. Example analyses show that the model can accurately identify the weak links of the preplanning system.The quantitative assessment system constructed in this study has gotten breakthroughs in three aspects：First，the establishment of a multi-dimensional evaluation framework of ‘standard compliance-process rationality-performance compliance. Second，the development of a hybrid AHP-FCE algorithm; and third，the innovation of a dynamic correction mechanism，so that the model can automatically optimise the indicator structure with the changes in the emergency environment. The study provides methodological support for the construction of China’s modern assessment system of nuclear emergency response capability，which has important theoretical value and practical guidance significance. Subsequent research will focus on expanding the applicability of the assessment model in the scenarios of nuclear emergency response collaboration and new reactor applications，and continue to improve the universality and accuracy of the model.