In order to reveal the complete geological structure of Xiangshan volcanic basin and explore the metallogenic prospect and potential in the central part of the basin, the Xiangshan Uranium Field Deep Scientific Exploration phase II project deployed a 3 000 meter deep scientific borehole, named CUSD2-1, at “Xingshuxia” in the central part of the basin. To insure the smooth conduction of the drilling, we adopted the advanced AC frequency conversion electric top drive geological core drill, large diameter wireline core drilling technology, anti-inclination and control wireline core drilling tools, high efficiency diamond bit and efficient drag reducing lubricating drilling fluid, which successfully solved the technical problems of deep drilling in complex formation, such as low drilling speed in hard rock, stable hole wall in broken formation, hole leakage, anti-inclination and control in strongly deflecting formation, and safe drilling with large diameter wireline coring, and finally drilled to the predetermined depth, creating the deepest record of S (φ150 mm) diameter wireline coring in geological core drilling in China, and revealed the deep formation structure. This deep drilling provides valuable geological data for deep uranium resource exploration in Xiangshan, which not only has special significance for the scientific research and exploration of deep uranium resources, but also has great significance for the improvement of engineering technology for deep-ultra deep geological drilling.

Delingha depression in the eastern Qaidam basin is believed a potential area for sandstone type uranium deposit in the target stata of the Neogene Shizigou formation and the Shangyoushashan formation. The in-depth investigation on the sedimentary facies characteristics and evolution of strata will provide valuable guidance for uranium exploration. Detailed observations of lithofacies assemblages and sedimentary formation in field outcrops，drilling cores, and well logging analyses have identified that the alluvial fan-braided river delta-lake are the dominant sedimentary facies type in the study area. Among these，the distributary channels in the braided river delta plain and subaqueous distributary channels in the braided river delta front are well-developed with significant scale and good connectivity，providing a favorable sedimentary environment for uranium enrichment. This new understanding has contributed to the knowledge of the spatial and temporal distribution of sand bodies in the Shizigou formation and the Shangyoushashan formations in the eastern Qaidam basin，and provided key information in guiding the future prospecting and exploration.

In recent years, significant progress has been made in the exploration of sandstone type uranium deposits in the Subash area of the Turpan-Hami basin. Exploration shows that heterogeneity of sand bodies is one of the key factors controlling uranium mineralization. This article systematically analyzes the thickness, sand content, sedimentary facies, aquiclude numbers, ore bearing sandstone grain size, and organic matter content of the Xishanyao formation in the Subash area, identifies the spatial variation characteristics of sand heterogeneity, and explores its relationship with uranium mineralization. The research results show that the thickness of sand bodies in distributary channels is relatively large, with good connectivity and strong homogeneity. The heterogeneity is strong at the bay between the distributaries, with well-developed mudstone barriers and thin sand bodies. The variation of spatial heterogeneity in sand bodies causes the changes in the direction of oxygen and uranium water transport, resulting in a decrease in fluid transport velocity, leading to uranium unloading and precipitation for the mineralization. In the Subashi area, the favorable condition for uranium mineralization is that the thickness of the sand body is 19-54m, the sand content is 60 % -80 %, the number of aquiclude is 3-5, and the lithology is fine sandstone at the transition between the underwater distributary channel and the bay with high organic matter content.

This article analyzes the petrological characteristics，geochemical features，provenance composition，structural background, and sedimentary environment of uranium bearing sandstone in the lower member of the Toutunhe formation in the Louzhuangzi area by the methods of geochemical analysis，microscopic identification and core observation，and preliminarily explores their relationship with uranium mineralization. The results show that the tectonic background of the ore-bearing sandstone source rocks in the lower member of the Toutunhe formation is mainly the active continental margin and the passive continental margin. The special tectonic background provided favorable conditions for the migration of uranium. The source of sandstone debris was dominated by neutral igneous rock，and the parent rock was mainly calc-alkaline granite with a small amount of pyroclastic rock，sedimentary rock and metamorphic rock，which indicated the sandstone from multi-source nature，and has a good uranium source. The sandstone formed in a warm and humid paleoclimate and the source rock was strongly weathered. The sandstone is rich in reducing medium，reflecting that the lower member of Toutunhe formation was in a reducing environment and has good primary reduction ability. The content of major elements of the sandstone debris in the target layer has the characteristics of rich alkali，high silicon and weak aluminum，and the ore-bearing sandstone are of lower w(SiO₂) and w(Al₂O₃) and higher w(CaO) than those of the sterile sandstone. The difference of component content in the sand body of the ore-bearing member is characterized by strong clay alteration and carbonate development. U，Mo and Se are relatively enriched，and other trace elements are relatively depleted except for Ga，which is comparable to the sedimentary rocks in China. The content of trace elements in ore-bearing samples of the same borehole is generally higher than that in sterile samples， U，Mo，Se，V，Ge，Ti，Sc and Y are significantly increased, which indicated that the trace elements in the sand body of the target layer also have migrated and enriched in the uranium mineralization process.

Pyrite is the most common metal sulfide mineral in mineral deposits，mostly formed at the stages of uranium mineralization. Its typological characteristics have important indicative significance for deep mineral exploration and prediction. This article uses electron microscopy，powder diffraction，thermoelectric analyzer，and electron probe system to analyze the typological characteristics of pyrite at different mineralization stages and elevations in the Shulouqiu uranium deposit. The research results show that the n（S）/n（Fe） values of pyrite in this area indicate a deficiency in S characteristics. Analysis of characteristic elements such as δFe，δS，As，Se，Co，Ni，etc. shows that the genesis of pyrite in this area is mainly magmatic hydrothermal. The characteristics of the crystal cell parameters of pyrite indicate that the substitution of S with As in a isomorphic form is the main cause of the increase in a₀ and also an important factor leading to the precipitation of U element. The thermoelectric coefficient value （a）of pyrite is -301.0~332.2 μV·℃^-1，and the thermal conductivity type is mainly P-type. The formation temperature of pyrite is 74~386 ℃，belonging to a medium low temperature deposit. The thermal electric coefficient dispersion （δa′）of pyrite indicates a mineralization period with a δa’of 82.1，indicating a relatively stable mineralization environment and a weak degree of superposition；The δa’values in the early and late stages of mineralization are 201.6 and 224.9，respectively，indicating that they may have been formed by the superposition of multiple stages of hydrothermal fluids，with a relatively high degree of superposition； The δa′ values at each stage gradually decrease with the decrease of levels，and are relatively concentrated，indicating that the mineralization become relatively better as the depth increases. The thermoelectric parameter X_np of pyrite is -40.0~61.0，and the erosion percentage（γ） of the ore body is 34.8 %~60.0 %，with an average of 48.9，indicating that the deposit has been eroded to the middle and still has significant extension in the deeper part. Comprehensive analysis suggests that there is still good mineralization and prospecting potential in the deep part of the deposit.

In order to explore the uranium mineralization specific characteristics of granite， the geochemical characteristics of Mesozoic-producing and non-producing uranium granites in the Nanling region were analyzed on the base of systematic collection of previous research. The results show that both uranium deposit host and non deposit granites are mainly formed by partial melting of Precambrian metamorphic sedimentary rocks，but the uranium deposit host granites are mainly formed by partially melting U-rich mudstones, while the non-deposit granites are the partially melted products of uranium-depleted sandstone. Compared with uranium deposit host granites，the biotite crystallization temperature in uranium deposit host granites is relatively low，F-rich and Cl-poor，and the magmatic melt has lower oxygen fugacity values，suggesting that uranium deposit host granites formed at relatively low temperatures and low oxygen fugacity. The low temperature, low oxygen fugacity，and F-rich physical and chemical environment are favorable for U to continuously enter the melt during the magma crystallization and differentiation and combine with oxygen to form uranite that are liable to undergo secondary alteration. The formation of uranite provides a good material basis for uranium mineralization.

Pingxi pluton is located in the northern section of the Taoshan-Zhuguang uranium mineralization belt，and a number of uranium mineralization occurrences have been found in the pluton by previous researchers，However，the systematical study were conducted on the uranium metallogenic conditions such as lithology，structure and alteration in the area，and the overall evaluation of uranium resource potential was not completed and no specific suggestions or opinions been put forward in the main mineralization control factors for the uranium exploration. In order to find the direction of next exploration，this paper systematically discussed the uranium mineralization characteristics of the pluton by geological investigation，physical survey and chemical analysis，analyzes the conditions of uranium mineralization and ore-controlling factors. The study concluded that the Pingxi pluton is a multi-stage S-type uranium-producing granite，with strong magmatic-tectonic hydrothermal activity，uranium mineralization is mainly controlled by the NNE-NE oriented fracture，and located at the intersection of different striking of fractures，the ore body is set in the fissures of the secondary fracture，which is often accompanied by multi-phase hydrothermal alteration，the hematitization and silicification is the main prospecting sign. The predicted favorite mineralization sectors are Shuangkeng-Fuzhu section where strong magmatic hydrothermal activity occurred in the early to late Yanshan period，with northeast trending Shankeng-Pingxi and northwest trending Luyuan-Hexi-Fuzhu ore controlling faults which extend stably into the deep with strong hydrothermal alteration such as silicification，hematitiztion and pyritization，and geophysical and geochemical anomalies are developed in the shallow and deep. Therefore there is great metallogenic potential in the deep and peripheral areas.

The Lianhua Mountain area in Yingjiang county，Yunnan province，is one of the several w regions in Yunnan that contains medium-high temperature geothermal resources. Previous geothermal research was more focused on meeting the actual production needs, lack of the in-depth exploration in aspects such as the sources of geothermal water chemical components，water-rock interactions，multi-method evaluations of reservoir temperatures，and the genetic mechanisms of geothermal systems. Based on hydro-geochemical methods，this paper aims to identify the circulation process of geothermal water and clarify the formation mechanism of the geothermal system. Through mathematical statistics and correlation analysis of hydrochemical indicators，Piper diagrams，Schoeller diagrams，diagrams of the relationships between anions and cations，hydrogen and oxygen isotope analysis，SiO₂ geothermal temperature scale，and the multi-mineral equilibrium method，a systematic study was carried out on the geothermal water chemical types，sources of major ionic components，recharge sources of geothermal water，reservoir temperatures，and circulation depths in the Yingjiang basin. Subsequently，the origin of geothermal water was inferred. The results show that the hydrochemical type of the geothermal fields in the Yingjiang basin is HCO₃-Na type. The major ionic components in the geothermal water originate from the dissolution of halide minerals，feldspars，fluorides，gypsum，and other minerals，and are influenced by cation-exchange reactions. The geothermal water is mainly recharged by mountainous atmospheric precipitation at an altitude between 1 348-1 571 m. The deep reservoir temperature is 168.2 °C. During the upwelling process，the geothermal water undergoes water-rock interactions and cation-exchange reactions with the surrounding rocks，resulting in the changes of its hydrochemical components. The heat source of the reservoir mainly comes from the magma chamber in the deep crust. Part of the heat is transferred upward in the form of heat convection through the connection of the Sudian-type fault zone，and the other part is transferred upward through rocks in the form of heat conduction. Atmospheric precipitation infiltrates and circulates along the water-conducting structure，absorbs the heat transferred upward by the magma chamber，and heated. Eventually，a convective-conductive composite hydrothermal system dominated by HCO₃-Na type water formed near the fault zone.

Underground Research Laboratories (URLs) play a crucial role in the siting process of high-level radioactive waste disposal. A study of evaluating the structural stability of Beishan URLs site was carried out, considering regional seismic and geological environment. After over a decade of site stability evaluations，techniques were developed to identify weakly active faults in stable crustal areas and assess their seismic potential. A method for determining design seismic motions was proposed，accounting for the source，propagation path，and local site characteristics. An efficient，high-precision time-domain analysis method for deeply buried，complex URL systems was proposed，along with a rock-structure numerical model to reveal seismic performance and its impact on the structural stability of the Beishan URL. The research determined the seismic fortification intensity for the Beishan URL，provided key seismic input parameters for structural design，and presented the seismic response results, supporting the construction of a site descriptive model (SDM) and site suitability assessment for the disposal repository.

The development of nuclear energy is inseparable from the treatment and disposal of radioactive waste. Geopolymer is a promising radioactive waste solidification material. In this study，metakaolin was used as the substrate to prepare metakaolin polymer, which was used to solidify Cs and real radioactive waste. The properties of metakaolin geopolymer were investigated by characterization and leaching experiments. Characterization experiments show that metakaolin geopolymer with three-dimensional network structure has high compressive strength, which can meet the strength requirements of radioactive waste solidified body. At the same time, the solidification of Cs in metakaolin polymer is uniform. However， the incorporation of Cs will hinder the growth of silicon and aluminum network skeleton and reduce the gel structure of the system，resulting in the increase of porosity and the decrease of compressive strength of geopolymer cured body. The leaching experiments of Cs and real waste water in deionized water and real groundwater show that metakaolin polymer has excellent Cs retention ability，and has low leaching rate and cumulative leaching fraction，which is better than the value specified in the national standard. In general，metakaolin geopolymer performs well in physical compression resistance and Cs retention，and is a material with great application potential.

To appropriate deal the high-level radioactive waste with internationally recognized method, deep geological disposal repository with multibarrier system is being planned to construct in China. As one of the most important engineering barriers，the canister should maintain integrity and avoid any deformation to meet the safety functions of containing radioactive waste and isolating it from groundwater over the design lifetime. Therefore，it is crucial to reasonably design the shape and thickness of the canister. The properties of the canister materials are important factors affecting the shape and thickness design of the canister. Carbon steel is one of the candidate materials for high-level waste canister in China. Since Japan has chosen carbon steel as the canister material and has completed the trial production of the canister， this paper mainly systematically introduced the design concept about basic shape and thickness of the canister for high-level radioactive in Japan，and analyzed the key factors that need to be considered in the design of the shape and thickness for the canister. Also, emphasis was placed on the determination of the pressure thickness parameter and radiation shielding thickness parameter to provide guidance for the design of the canister for high-level radioactive in China.

A year-long investigation of air radon concentration at Beishan URL site and its surrounding areas was carried out using solid-state nuclear track detectors at 24 points，with quarterly sampling and measurements conducted. The results indicated that the annual radon concentration in the region ranged from 10 to 64 Bq·m^-3，with a geometric mean (GM) of 27 Bq·m^-3. The overall radon levels exhibited distinct seasonal variations, with the highest concentrations occurring from April to June and the lowest from January to March. The differences in radon concentrations between different areas were small and remained relatively stable. Construction disturbances in the active construction zones had a localized impact on radon concentrations，but due to favorable air diffusion conditions，this effect did not result in a widespread increase in radon levels. This suggests that the direct impact of human activities on regional radon concentrations is limited. According to the Pearson correlation coefficient analysis，a significant positive correlation was observed between temperature and radon concentrations，with radon levels increasing as temperatures rose at most measurement points. In contrast，the influence of wind speed on radon concentrations was more complex，with considerable variability in correlation across different points，likely influenced by other factors，warranting further investigation. This study provides data support and practical insights for long-term radon monitoring and health risk assessment at the Beishan URL.

Nuclear power thermal discharge is one of the important factors affecting the surrounding environment during its operation，which can have an impact on the temperature，water quality，and distribution of aquatic organisms in the nearby sea area. This article provided an overview of the current status of nuclear power thermal discharge monitoring technology both home and abroad，including traditional monitoring methods，remote sensing monitoring methods(satellite remote sensing，aerial remote sensing)，numerical simulations and physical model experiments，as well as emerging technologies (unmanned underwater vehicles，sensor networks and biological monitoring); the advantages and disadvantages of existing technologies and the facing challenges were analyzed，an outlook was provided on future technological development trends，emphasizing the importance of high-resolution satellite remote sensing technology，unmanned aerial vehicle remote sensing technology，and intelligent real-time monitoring systems. The review provides reference for nuclear power plant thermal discharge monitoring，promote innovation and development of related technologies，and better reservation of the marine environment.

With the rapid development of China’s nuclear power industry，the impact of thermal discharge on the surrounding marine environment is increasingly attracting attention. Objective and accurate background temperatures are crucial for accurately assessing the thermal effects of warm water discharge. In this article, the sea area near a nuclear power plant in Fujian was studied. Based on long-term thermal infrared satellite data before the operation of the first unit，the distribution of sea surface temperature field under different seasons and tidal conditions was obtained through temperature inversion. By using grid method and correlation analysis method，the sub zones with the highest temperature correlation inside and outside the submersible discharge area were determined，and a continuous background temperature field with multi-point temperature coupling was constructed. The temperature rise field was extracted using recent thermal infrared satellite data，and the impact of the operation of four units on the temperature rise in the nearby sea area was evaluated. The results shows that using the multi-point temperature substitution method to extract the reference temperature is effective and reliable. Before the operation of nuclear power，the temperature field in the study area showed significant temperature differences and band like distribution characteristics：in winter，the temperature gradually decreased from offshore to nearshore，while in summer and other months with higher temperatures，the opposite trend was observed. After the operation of the nuclear power plant，there was a significant temperature rise area in the sea area near the discharge outlet. During the ebb tide period，the temperature discharge mainly affected Qingchuan Bay，while during the flood tide period，both Qingchuan Bay and Wendu Bay were affected. The area of temperature rise exceeding 2.0 ℃ is larger in winter than in summer under the same tidal state，and the area during high tide is larger than that during low tide in the same season.

This article made a temperature field analysis in a nearshore waters of a nuclear power plant in Fujian Province，and uses Landsat-8/9 TIRS thermal infrared satellite remote sensing data was used to study the temperature field distribution characteristics in different seasons before and after nuclear power operation. The research results show that the temperature inversion results of Landsat-8/9 TIRS data based on the radiative transfer equation algorithm have high reliability. Before the operation of nuclear power plants，there were significant differences in temperature field characteristics in different seasons in the sea area near the nuclear power plant site. In winter，the temperature field was generally more uniform，slightly higher in the south than in the north and slightly higher in the east than in the west. The water temperature near the water intake was slightly higher than that near the drainage outlet. The maximum temperature difference within 4 km of the plant site was about 1.5 ℃，and within 2 km was about 1.0 ℃. In summer，there was a large temperature difference in the region，showing the characteristics of being higher in the north and lower in the south，and higher in the west and lower in the east. The maximum temperature difference within 4 km of the plant site was about 5.5 ℃，and within 2km was about 2.5 ℃，and some parts were distributed in a disorderly manner. The water temperature near the drainage.After the operation of the nuclear power plant，the characteristics of the regional temperature field are basically the same as before，but there are obvious high-temperature bright spots at the drainage outlet，with a maximum temperature exceeding the surrounding area by 3.0 ℃. The intensity and area of the high-temperature bright spots in winter are greater than those in summer，indicating that the impact of thermal drainage discharge on the temperature field in the nearby sea area is stronger in winter than in summer.The flow direction of the current affects the local distribution of the temperature field，and the diffusion direction of the warm water discharge is related to the flow direction of the current. The Landsat-8/9 TIRS data basically meet the needs of regional temperature field distribution research，but it is difficult to realize the monitoring of full tidal temperature and drainage.

This paper established a high-temperature infrared method to determine the total carbon in nuclear grade boron carbide. The optimal experimental conditions were determined by studying the testing temperature，sample weight，selection of flux，and flux coverage method. At the same time, accuracy，precision，detection limit and quantification limit of the method were determined. The results show that the optimal testing temperature is 1 400 ℃，which not only ensures the release of total carbon but also extends the service life of the instrument. The optimal sample weight is 20-30 mg. Tin particles has the best melting effect，and boron carbide has the highest carbon release efficiency. The best coverage method was found to be 0.4 g tin particle + boron carbide + 0.6 g tin particle，and the carbon in boron carbide was totally released. The high-temperature infrared method for determining total carbon in nuclear grade boron carbide is good in accuracy and precision，the test results of boron carbide certified reference material are all within the uncertainty range of the certified value, while the RSD is<1.5 %, and the detection limit of the method is 0.001 9 %. This method is simple and fast，it can meet the requirements for measuring total carbon in nuclear grade boron carbide.

The microscopic pore structure is of great significance to the study of concrete materials. However，the traditional pore structure testing methods， such as nuclear magnetic resonance (NMR)，mercury intrusion porosimetry (MIP)，optical microscopy，X-ray tomography (X-CT)，and nitrogen adsorption，still have some limitations in terms of pore morphology and nanoscale pore characterization. In this study，we proposed to use argon ion polishing-scanning electron microscopy method to study the microscopic pore structure in concrete，prepared concrete samples with high-quality mechanically damage-free surfaces， and qualitatively investigated four types of pore structure in concrete. Large-area backscattered electron images were collected, and the pore porosity，pore diameter，pore shape factor，and graded porosity of the pore structure were quantified by ImageJ，Avizo，and other software. This method achieves the qualitative analysis and quantitative characterization of concrete microporous structure, which is of reference significance for the research and analysis of the microstructure of concrete materials.

The rapid identification of radionuclides is a critical component of nuclear material detection systems，essential for improving the performance and efficiency of radiation detection. Traditional nuclide spectrum recognition methods typically involve multiple complex steps，such as noise reduction，background subtraction，and feature extraction，which are computationally intensive，time-consuming，and inefficient，making them unsuitable for rapid response in practical applications. To address these issues，this paper proposed a rapid nuclide spectrum recognition algorithm based on the MobileNetV3 neural network，which achieved efficient nuclide recognition by optimizing data processing and model training methods. A series of simulated datasets were generated using Monte Carlo (MCNP) simulation software，including scenarios with different radioactive sources and particle counts，varying distances between NaI detectors and the sources，and mixed nuclide environments. These diverse datasets were used to train and validate the network model，enhancing its generalization capability. To better process the full-energy peak characteristics of gamma spectra，this study designs a preprocessing method based on a sliding window approach，which incrementally transforms one-dimensional spectral data. Subsequently，the transformed spectral data is mapped into two-dimensional grayscale images using Hilbert curves and input into the MobileNetV3 model for training and prediction. Experimental results demonstrate that the proposed neural network model performs exceptionally well in rapidly processing spectrum data handled by the sliding window method，achieving high-precision recognition of different nuclides while maintaining efficient learning. In terms of model performance，using sliding window sizes of 23 and 25 results in faster convergence and significantly improved recognition accuracy. This study highlights the effectiveness of integrating deep learning with nuclide spectral characteristics，providing a novel and efficient solution for nuclear material detection systems.

In order to accurately measure ²³²Th in the waste residues of associated radioactive mines, especially for the measurement of slag samples under non-equilibrium conditions, and to provide data support for radiation environment supervision, a method for measuring ²³²Th in slag using a high-purity germanium γ spectrometer was established. The method involves indirect measurement by selecting the characteristic γ rays of the daughter nuclides in the decay chain of ²³²Th, and calculating its specific activity by the relative comparison method. The slag samples in a non-equilibrium state are sealed for 20 days to enable ²²⁸Ra and ²²⁸Ac to reach equilibrium, and ²²⁸Th, ²²⁴Ra and subsequent daughter nuclides to reach equilibrium. Then, the specific activity of the parent nuclide ²³²Th is obtained through conversion relationships. This method is accurate and efficient, with a detection limit of 1.1 Bq・kg^-1, a precision better than 5 %, and a relative error lower than 5 %. The method of measuring ²³²Th in slag using a high-purity germanium γ spectrometer does not require complex chemical treatment, which makes up for the deficiencies of inductively coupled plasma mass spectrometry. The calculation method under non-equilibrium conditions is also more reliable than using the average value of a single characteristic peak or multiple characteristic peaks.