Gas Release Research Articles

TRISO Fuel’s Safety Functions, Contributions to Reactor Safety, and Necessary Safety Limits

Safety functions are the actions, passive or active, that structures, systems, and components of a nuclear facility contribute to the safety of the workers, the public, or the environment. Well-defined safety functions are the foundation of a solid safety case for a reactor. For reactors that use tri-structural isotropic (TRISO)-coated particles, the TRISO fuel plays an important part in the safety case because of its ability to contain radionuclides in the fuel itself. This ability enables the use of a functional containment strategy for the reactor where radionuclide retention is the primary safety function supported by the safety functions of controlling reactivity control and controlling heat rejection. This paper establishes at a deeper level the role that TRISO fuel plays in each of these safety functions and the associated quality assurance and testing requirements for TRISO particle manufacturing to ensure these safety functions. Safety limits necessary to protect these safety functions include manufacturing specifications, operational limits, time-at-temperature limits, and fission gas release activity limits. This approach demonstrates the role that specific aspects of TRISO fuel play in protecting the safety of workers, the public, and the environment.

EVOLUÇÃO DE C-CO<sub>2</sub> EM SOLOS DE DIFERENTES ECOSSISTEMAS NA REGIÃO DO ALTO ACRE, ACRE, BRASIL

Different studies, developed over the years, have shown that the increase in human activities on the soil can influence the release of gases related to the increase in the greenhouse effect. In this sense, the use of methods that evaluate the evolution of C-CO2 has been considered as important indicators to detect changes in the environment, since they can be influenced by the crop and its cultivation system as a result of impacts on microbial activity. The objective of this work was to evaluate the release of C-CO2 from soils submitted to different ecosystems. Laboratory tests were carried out where soil samples, submitted to five different ecosystems, were collected in three different periods throughout the year in the municipalities of Brasiléia and Epitaciolândia, Alto Acre region, in the state of Acre, and were subsequently incubated. Subsequently, the evolution of C-CO2 was evaluated, and the readings were carried out periodically until the 500th day of incubation of the samples. The data were analyzed in order to evaluate the effect of different plant species on the evolution of C-CO2. Regarding the collection carried out in April, there was no difference in the evolution of C-CO2 between the areas. However, in the month of June, which comprises the period of the beginning of the transition between the rainy season and the dry season, and in the month of August, the dry season, it was observed that in the area of native forest occurred the highest values of C-CO2 flux, differing statistically from other areas within these months of collection. Between the collection times, only in the area of agroforestry system no significant differences were recorded in the evolution of C-CO2. The highest accumulated values of C-CO2 were recorded in the following sequence: native forest > agroforestry system > area with cassava > cultivated pasture > area with banana. It is concluded that the areas that present a greater contribution of plant material to the soil can serve as a stimulus to the development of microorganisms that, consequently, increase the flow of CO2, especially until the beginning of the dry season and that the absence of moisture negatively influences the emission of C-CO2, causing significant differences in the amount of release of C-CO2 between the study areas at the same time of evaluation.

3D Printing of Graphene Aerogel Microspheres to Architect High-Performance Electrodes for Hydrogen Evolution Reaction.

The hydrogen evolution reaction (HER) efficiency is highly dependent on the electrocatalysts microstructure and the macrostructure of the electrodes. Herein, the graphene aerogel microspheres loaded with well-dispersed ultrafine Ni/Co nanoparticles catalyst is prepared through electro-spraying, in-situ crosslinking, freeze-drying, and pyrolysis, and then is utilized to print the HER electrode via direct ink writing (DIW). The obtained graphene-based aerogel microspheres possess peculiar cabbage-like mesoporous structures which allow ready access of reaction species to active sites, optimal mass transfer, and proton diffusion within the microspheres. DIW 3D printing achieves the ordered control on the periodic lattice macro-geometry and thus facilitates the fast gas bubble evolution and release from the electrode surface. The as-fabricated 3D electrode possesses a low overpotential of 341 mV at 10 mA cm-2, a decrease by 31.5% compared to 3D printed electrode directly from 2D graphene, and a low Tafel slope of 119.1 mV dec-1, 40% lower than that of the electrodes fabricated via directly casting the aerogel microspheres. Furthermore, the 3D-printed electrode of aerogel microspheres displays good HER stability. This work provides a good approach for constructing high-performance HER electrodes through 3D printing of graphene aerogel microspheres.

PRA Melting-ICE Project: Svalbard 2022 Expeditions Report

Arctic regions are among the fastest warming areas of the planet. Increasing average temperatures over the last five decades have deepened the thawing of the upper-most layer of permafrost across the Arctic, which contains significant amounts of organic carbon. The progressive deepening of seasonal thawing releases carbon that is used by active microorganisms which also produce greenhouse gases, potentially onsetting a positive feedback on global warming. Despite their importance in controlling organic matter degradation and greenhouse gas fluxes to the atmosphere, there is a lack of data on activity and dynamics of microbial communities in High Arctic soils in response to seasonal thaw. This report describes three specific expeditions performed on the Svalbard archipelago, carried out within the framework of the PRA (Italian Arctic Research Program) project Melting-ICE, performed between February and October 2022, reporting site characteristics and samples collected. The project aims to investigate the diversity and activity of active layer microbial communities across a full season thaw cycle, correlating microbial diversity with gas fluxes and composition. During these expeditions, a total of eight different sites were selected to investigate the microbiology and geochemistry of soils, as well as to estimate the gas fluxes from the soil to the atmosphere. The data collected in the field, combined with the results obtained in the laboratory, will provide a snapshot of the seasonal activity of the microbial communities present in the permafrost’s active layer. The three campaigns will provide data to estimate the impact of permafrost melting on the carbon cycle and the role of microorganisms in the release of greenhouse gases.

Effects of selenate on greenhouse gas release and microbial community variations during swine manure composting

Co-composting of livestock manure and selenate is an effective means to produce selenium-rich organic fertilizer. However the effect of selenate on greenhouse gas emission during composting is still unknown. To probe the influences of selenate on greenhouse gas and microbial community changes during swine manure composting. Various dose of selenate were added to the fresh swine manure and wheat straw for 80 days aerobic composting, sequentially labeled as T1 (control) to T6 (0, 1, 2, 3, 4 and 5 mg kg−1). Results indicated that selenate generally increased the nitrous oxide (N2O) and ammonia (NH3) emissions while presented varying impacts on methane (CH4) emissions. Compared with the control, adding 2 and 5 mg kg−1 selenate reduced the CH4 emission by 39.60% and 13.75%, respectively, while other concentrations presented opposite results. Meanwhile, adding 2 mg kg−1 selenate could reduce the global warming potential and improve the compost maturity. According to the microbial results, adding 2 mg kg−1 selenate enhanced the richness and variety of the microbes and might influence Proteobacteria, Chloroflexi, Actinobacteria and Methylococcaceae_unclassified to decrease the global warming potential.

Local exhaust characteristics of a cultural relic restoration workbench for different exhaust areas

The release of harmful gases and dust during the restoration of cultural relics has been a long-standing problem that cannot be ignored. A workbench is proposed for discharging pollutants during cultural relic restoration. The workbench adopts an exhaust air mode, which can reduce the area of the exhaust control plane and reduce the exhaust air volume of a semi-enclosed space through an air curtain at both ends. A theoretical analysis, experimental tests, and visual experiments are conducted to investigate the effectiveness of the proposed exhaust mode. The results indicated that the air curtain at both ends can effectively improve the exhaust-air velocity of the exhaust control plane. For an exhaust-air flow rate of 972 m3/h, increasing the air-supply velocity at the slot vents from 0 to 4.86 m/s causes the average exhaust-air velocity to increase from approximately 0.24 m/s to 0.34 m/s. Combining an exhaust-air flow rate of 766 m3/h with an air-supply velocity of 3.61 m/s requires a 37% lower exhaust-air flow rate per unit pollutant production rate than that required using pure exhaust air. The exhaust mode of the cultural relic restoration workbench has enormous potential for energy savings in ventilation.

Wave-transparent and eco-friendly flame-retardant phosphorus-based phthalonitrile/quartz composites by a synchronized self-curing strategy with cyano and alkynyl groups

The robust human–machine interaction systems of the aerospace industry necessitate the development of thermal resistant wave-transparent composites, with a pivotal focus on organic resin matrix. However, enhancing the heat resistance of such materials while preserving other critical attributes has been a formidable challenge. In this study, a novel designed strategy of a dual-curing functional phosphorus-based phthalonitrile monomer (P-ALK-PN) has been proposed. The optimized curing temperatures for intra- or intermolecular Diels-Alder reactions of alkynyl groups and polyaddition reaction of cyano groups resulted in a homogeneous and highly crosslinked N-enriched phthalonitrile system. After curing at 450 °C, the resin, namely P-ALK-PN-450 °C, demonstrated exceptional thermal stability (T5% = 644 °C), thermo-oxidative stability (T5% = 554 °C), and char yield at 800 °C (90.7 % in N2 and 67.5 % in air). Their quartz fiber reinforced composites (P-ALK-PN/QFs) were subsequently fabricated by the hot-pressing process. Upon post-curing at 420 °C, P-ALK-PN-420 °C/QF displayed elevated glass transition temperature (550 °C), flexural strength (319 MPa), and relatively low dielectric properties with a dielectric constant (Dk) of approximately 4.2 and a dissipation factor (Df) less than 0.02 across a wide temperature ranging from 25 °C to 600 °C. Especially, it exhibited excellent flame retardancy (only a 6.7 % weight loss at ambient temperatures exceeding 1300 °C for 200 s) as well, stemming from release of eco-friendly inert gases (NH3) and formation of a graphitized protective layer during pyrolysis. These promising results highlight the potential applications of P-ALK-PN resins in aerospace and high-performance engineering fields.

Unveiling Gas Seeps: A Dive into Water Column Data Analysis

Abstract Multibeam Echo Sounders (MBES) have significantly advanced underwater acoustic data analysis, allowing for the detection of various marine features. The enhanced capabilities of water column acoustic data analysis by MBES have played a crucial role in numerous research projects, including mapping methane gas flux and studying free gas release. This research aims to detect and quantify underwater gas seeps by leveraging the advanced imaging capabilities of MBES. The workflow involved displaying water column data, removing irrelevant echoes, applying amplitude threshold filtering, validating Local Intensity Maxima (LIM) values, exporting final coordinates, and calculating volumes using voxel-based methods. Results showed that higher frequencies (200 and 400 kHz) provided more detailed and accurate gas seep detection at 30 m depth, with average volumes of 25.972 m3 and 31.050 m3, respectively. However, at a depth of 60 m, the 100 kHz frequency was more effective, with an average volume of 28.324 m3. These findings underscore the importance of frequency selection in MBES surveys for accurate gas seep detection and quantification. This study provides valuable insights into underwater gas seeps, enhancing our understanding of their impacts on the marine environment and the global carbon cycle. This study supports SDG 14 by advancing marine ecosystems, including the management of marine resources.

Soft interface instability and gas flow channeling in low-permeability deformable media

Understanding gas percolation through a clay layer or a shale formation is of great importance for the development of a geologic repository for nuclear waste disposal, a subsurface system for gas storage, and an engineering approach for hydrocarbon extraction from unconventional reservoirs. Gas injection experiments have revealed complex dynamic behaviours of gas percolation through water saturated compacted bentonite, characterized by a high breakthrough pressure, rapid breakthrough, a pressure/stress decay after the breakthrough, a relatively high migration rate, high-frequency periodic/nonperiodic variations in flow rate, stepwise rate reductions during relaxation, and low gas saturation over the whole process, all indicating channelling nature of the processes. Using linear stability analyses, we show that this channelling can autonomously emerge from the instability of the deformable interface between the injected gas and the compacted bentonite matrix driven by local stress concentration, pore dilation, and hydrologic gradient. Channel patterns formed would possess a fractal geometry. We further show that, once a percolating channel is established, the gas injected would percolate through the channel in a chain of gas bubbles, also due to the interface instability, resulting in periodic/chaotic variations in gas flow rate. Our work provides a unified explanation for key features observed for gas percolation in low-permeability deformable media. The work also suggests a possibility of designing an engineered barrier system for a nuclear waste repository that can have controllable gas release while limit water transport.

Laboratory-based assessment of geotechnical characteristics of organic waste-amended soil for landfill biocover.

A landfill biocover is essential for addressing environmental concerns, especially in waste management, as it plays a crucial role in mitigating the release of methane gas. This study investigates the geotechnical characteristics of soil amended with organic wastes for landfill biocover applications. Various organic waste amendments, viz., rice husk, crushed coconut coir, and compost, were examined at different percentages (0%, 25%, 50%, and 75%) compared with conventional landfill cover material, i.e. natural clay, as biocovers. Laboratory experiments analysed geotechnical characteristics, including organic content, Atterberg limit, compaction, consolidation, and desiccation cracking. The study revealed that organic waste amendment significantly impacted the geotechnical characteristics of landfill biocover, enhancing organic content and porosity and reducing permeability and desiccation susceptibility. Soils amended with organic content support methanotrophic bacteria growth and reduce methane emissions in landfills. The most promising biocovers were identified as 75CR (crushed coconut coir/wastewater sludge/clay in percentage ratio of 70:5:25), followed by 75CT (compost/wastewater sludge/clay in percentage ratio of 70:5:25), and 25RH (rice husk/wastewater sludge/clay in percentage ratio of 20:5:75). Biocovers offer sustainable landfill alternatives, underscoring the need to understand their geotechnical characteristics for successful installation in landfills.

Magmatic activity in incipient continental break-up as revealed by coupling melt and fluid inclusions

Abstract Deciphering deep magmatic processes driving the onset of continental break-up is fundamental to constrain our understanding of plate tectonics. The East African Rift System (EARS) is the only currently active system on Earth to study distinct stages of rift evolution. We present a coupled analysis of melt and fluid inclusions in the Virunga Volcanic Province (VVP) offering an unprecedented insight into the dynamics of incipient rifting and its evolution. Our study highlights that melting of distinct metasomes in the deep lithosphere is a common feature of immature rifts. In the VVP, it leads to the emission of nephelinitic and basanitic melts at Nyiragongo and Nyamulagira volcanoes, respectively. Additionally, the chemical composition of melt and fluid inclusions supports the identification of another magmatic series in the area. Related alkali basaltic melts would be produced by contemporary melting of a less enriched domain in the upper lithosphere, more classically documented in mature rifts. Various extents of mixing and crystallisation of these three distinct magmatic series occur in the lower crust beneath the VVP where the barometric estimates are consistent with the presence of a thick seismic low velocity zone (LVZ). The involvement of alkali basaltic melts in the regional magma production could be also detected in the spread of gas emissions in the rift valley and in the fumaroles of the main active volcanoes. Melting of the corresponding mantle domain is an added source of gas release that may largely contribute to CO2 emissions along the EARS.

Reassessing the Role of Thermal Convection in Simultaneous Water Production and Pollutant Degradation in Interfacial Photothermal-Photocatalytic Systems.

The interfacial photothermal-photocatalyticsystemscan generate clean water while purifying wastewater containing organic pollutants, but the impact of thermal convection on synergistic effects remains unexplored. This paper aims to regulate the thermal convection at the interface to significantly enhance the synergistic effect of interfacial photothermal-photocatalytic systems. A novel heterogeneous structure comprising iron-based metal-organic frameworks and multi-walled carbon nanotubes with a gelatin-polyvinyl alcohol (PVA) double network hydrogel (MWCNTs@NM88B/PVA/gelatin hydrogel, denoted as MMH) is developed and employed in the construction of the solar-driven interfacial evaporation (SIE) system. The system shows high activity for solar water evaporation and simultaneous photocatalytic degradation of organic pollutants. MMH demonstrates an evaporation rate of 2.84kg m-2h-1, achieving an efficiency of 95.3% under 1 sun. COMSOL simulations reveal that the implementation of a three-phase interface configuration with SIE technology significantly boosts thermal convection, effectively diminishing the barrier to gas release from the reaction system and consequently enhancing the efficiency of the interfacial photothermal-photocatalytic process. Furthermore, the potential mechanism of photocatalytic decomposition of organic pollutants in MMH/H2O2/visible light reaction system is proposed by combining the experiments of KPFM, in situ XPS, and ESR spectra. Therefore, this work offers a fresh perspective on evaluating the impact of thermal convection on water evaporation and pollutant degradation in interface photothermal-photocatalytic systems.

Validation process against late phase conditions of the passive autocatalytic recombiner simulation code PARUPM as a standalone tool using experimental data from REKO-3 and THAI facilities

In case of a nuclear accident with core damage in a light water reactor, the oxidation of the fuel cladding and other materials could lead to the release of combustible gases (H2 and CO) to the containment building. To mitigate the potential risk of combustion of these gases, passive autocatalytic recombiners (PARs) have been installed in numerous nuclear reactors in Europe and worldwide. PARs recombine H2 and CO with O2 producing H2O and CO2, respectively, without an open flame.PARUPM is a code that simulates the behaviour of PARs using a physicochemical model approach. In the framework of the AMHYCO project (EU-funded Horizon 2020 project), which seeks to advance the understanding and simulation capabilities to support the combustion risk management in severe accidents, the code has been extensively enhanced and developed to simulate PAR operation with H2/CO/O2/steam mixtures. Alongside these new capabilities, the code needed a new validation process.In this paper, the process of validation of PARUPM as a standalone code is described. The validation for steady state conditions was achieved through comparison with REKO-3 experimental data while the transient conditions were compared with results obtained with the THAI test facility. A thorough analysis of the code capabilities was performed by comparing the numerical results with experimental data for a broad series of conditions, namely: a range of different input gas temperatures and concentrations, oxygen starvation, CO poisoning, etc.

Hydrogen sensors of Ce-doped MoS2 with anti- humidity for early warning thermal runaway in lithium-ion batteries

Early warning of thermal runaway in lithium-ion batteries is critical to improving their safety and reliability in energy storage systems, electric vehicles, and other applications. Analyzing gas release, especially H2, is a suitable indicator for early warning of thermal runaway, but the sensitivity and service life of gas sensors are highly susceptible to humidity. Herein, we develop a H2-based sensor to monitor the thermal runaway of lithium-ion batteries using Ce-doped MoS2 modulated by amphiphiles. The unique amphiphiles provide a hydrophobic protective layer, ensuring stability in high-humidity environments for H2 detection. Applying this gas sensor for monitoring thermal runaway in lithium-ion batteries offers a 76-s advance warning compared to traditional temperature signals, effective in both overcharge and overheating induced thermal runaways. While this study presents an effective gas sensor for early thermal runaway warnings in lithium-ion batteries, further optimization is required for future applications due to its high sensitivity to temperature fluctuations (100 ppm H2/°C).

Experimental and Theoretical Insights on Gas Trapping of Noble Gases in MFU-4-Type Metal-Organic Frameworks.

Isostructural metal-organic frameworks (MOFs), namely MFU-4 and MFU-4-Br, in which the pore apertures are defined by anionic side ligands (Cl- and Br-, respectively), were synthesized and loaded with noble gases. By selecting the type of side ligand, one can fine-tune the pore aperture size, allowing for precise regulation of the entry and release of gas guests. In this study, we conducted experiments to examine gas loading and release using krypton and xenon as model gases, and we complemented our findings with computational modeling. Remarkably, the loaded gas guests remained trapped inside the pores even after being exposed to air under ambient conditions for extended periods, in some cases for up to several weeks. Therefore, we focused on determining the energy barrier preventing gas release using both theoretical and experimental methods. The results were compared in relation to the types of hosts and guests, providing valuable insights into the gas trapping process in MOFs, as well as programmed gas release in air under ambient conditions. Furthermore, the crystal structure of MFU-4-Br was elucidated using the three-dimensional electron diffraction (3DED) technique, and the bulk purity of the sample was subsequently verified through Rietveld refinement.

Experimental investigation and statistical analysis of performance of ceramic fiber-reinforced warm asphalt mixtures containing reclaimed asphalt pavement

Asphalt recycling can help conserve natural resources while reducing associated costs. However, the production of hot mix asphalt (HMA) with reclaimed asphalt pavement (RAP) generates a high heat rate, leading to the stiffening of the asphalt binder and the release of toxic gases. Warm Mix Asphalt (WMA) is a cost-effective technique that softens and delays the aging of the asphalt binder while producing asphalt mixtures at lower temperatures, resulting in decreased energy usage and harmful pollutants. However, increasing the RAP content in WMA mixtures could have a detrimental impact on several asphalt mixture properties, such as fatigue and moisture resistance. Consequently, increasing the RAP content in WMA mixes could require devising a strategy to offset the drawbacks of RAP material. Fibers are recognized as one of the additives that are incorporated directly into the mixes and improve the fatigue and moisture resistance of asphalt mixtures. Therefore, this study is conducted to evaluate the impact of ceramic fibers (CFs) on the performance of WMA-RAP mixtures. The response surface methodology (RSM) was employed to find out how the CFs changed the responses of WMA-recycled asphalt mixes at low and intermediate temperatures. These responses included Marshal stability, rutting resistance, moisture susceptibility, and fatigue life resistance. RSM was used to find the best amounts of factors like CFs, WMA additive (Sasobit), and RAP using central composite design (CCD). The results of the analysis of variance (ANOVA) showed a significant interaction between the CFs, RAP, and Sasobit. The CFs significantly improved every studied attribute, particularly the fatigue life at 5 °C and 20 °C. The excellent value of the adjusted coefficient of determination (adjusted R2) of all responses indicates a excellent correlation between the model and experimental results. The outcomes of the validation test demonstrate that every response has a percentage error of less than 5 %, exhibiting strong agreement and the accuracy of the model.

EPMA and EBSD observations of unirradiated MIMAS-MOX fuels for the study of fission gas release and thermal conductivity

ABSTRACT MOX fuel fabricated through the micronized master blend process (MIMAS) is used in light water reactors. The MIMAS-MOX fuel is characterized by a non-uniform plutonium distribution with plutonium-rich agglomerates. The distributions of plutonium and crystal grains can respectively influence the fuel properties and behaviors during irradiation. However, it was difficult to examine the correlation between the distributions of plutonium and crystal grains in an unirradiated MIMAS-MOX fuel because chemical etching for the grain boundary had little effect on the plutonium-rich agglomerates. In this study, the analytical techniques of electron probe micro analyzer and electron backscattered diffraction were applied to the observation of unirradiated MIMAS-MOX fuels. The observation using the two analytical techniques revealed crystal grain distributions in the phases with different concentrations of plutonium, including plutonium-rich agglomerates. In addition to the observation, the fission product gas release and thermal conductivity of MIMAS-MOX fuels were briefly discussed as initial approaches aiming to model them based on the results of the observation using the techniques of electron probe micro analyzer and electron backscattered diffraction.

Flow of a viscous dispersing gas-air mixture due to a sudden release of gas into the mine atmosphere

Flow of a viscous dispersing gas-air mixture due to a sudden release of gas into the mine atmosphere

Gas Box Exhaust Design Modification for Accidental Hazardous Gas Releases in Semiconductor Industry

Hazardous substances such as hydrogen and chlorine are used in semiconductor manufacturing. When these gasses are discharged, they are mixed with outside air and are connected to a treatment facility through a duct inside a gas box. This study investigated an optimal exhaust design to prevent fire explosions and toxic exposure by optimizing the exhaust volume when hazardous substances leak from the gas box of semiconductor manufacturing equipment. In this study, carbon monoxide was used for modeling. A 75 mm duct was used, and the tracer gas was released into the gas box at 15.4 LPM. The concentrations were measured at nine points inside and outside the gas box. According to the test results, in an experiment designed with 0% air intake, the internal leakage concentration was measured to be more than 25% of the LEL (lower explosive limit) for 10 min when leakage occurred due to stagnant flow, and the outside toxicity concentration was also measured to be more than 50% of the TWA (time-weighted average) value. When the air intake ratio was designed to be 100%, there was a point on the outside that exceeded 50% of the TWA, confirming that excessive air intake could also cause gas to leak outside. Finally, when the intake ratio was designed to be 50% in both directions, it was confirmed that the airflow was maintained smoothly, and the hazardous gasses were safely diluted and discharged through the duct. This study was conducted to improve the safety of workers in the field in the event of leakage of flammable and toxic gasses by testing the location and area of the air intake hole in the gas box exhaust port. Through this effort, the aim is to present specific standards for gas box design and to assist in establishing a legal framework or standardized guidelines.

Investigation on spontaneous fires regions in coal gangue hills using UAV thermal infrared images

ABSTRACT The spontaneous combustion of coal gangue hills is accompanied by the release of toxic gases and the infiltration of metal elements, posing a serious threat to the global ecological environment. The current temperature monitoring methods for coal gangue hills have certain limitations, hence advanced and timely temperature monitoring is crucial for the management of coal gangue hills. This paper takes Guojiahe coal gangue hill as an example, thousands of visible light and thermal infrared images are obtained by using an unmanned aerial vehicle, and the 3-D model of the surface temperature of the gangue hill is established with Gaussian kernel technique and Random Sampling Consensus Method (RANSAC). Furthermore, the high-temperature zone in the gangue hill is measured by handheld thermocouples. The results indicate that high-temperature areas are distributed in a circular pattern and mostly concentrated on the slope surface and the boundary line between the slope and the bench. The thermal images can reflect the temperature inside the gangue hill by comparing the results of thermocouple temperature measurement and UAV detection. Further, it is analyzed that the air leakage cracks formed on the slope of the gangue hill provide a channel for the combination of coal gangue and oxygen, accelerating the heat accumulation, and the three-field coupling mechanism of coal gangue spontaneous combustion is proposed. This study can provide technical and methodological support for the prevention and control of spontaneous combustion in coal gangue hills.