Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-07-01
Abstract： [Background]: Uranium polymetallic ores are strategic emerging industry minerals, and the quantitative analysis of uranium (U) in ores is a crucial step in the development process of such ores. [Purpose]: In this paper, a quantitative analysis of U in uranium polymetallic ores using femtosecond laser-induced breakdown spectroscopy (LIBS) combined with partial least squares regression (PLSR) modeling was conducted. [Methods]: Initially, the concentrations of U in six samples were measured by high-purity germanium gamma spectrometer and set as reference values, and then femtosecond lasers were employed to ablate the samples to obtain LIBS spectra. Subsequently, two normalization methods were applied to preprocess the raw spectra, and the impact of the preprocessed spectra on PLS model prediction analysis was compared with that of the raw spectra. Subsequently, the spectral data from five sets of samples were utilized as a training dataset to construct a quantitative model, enabling the analysis and prediction of U concentration in sample 3# [Results]: The results indicate that the relative standard deviation (RSD) and mean relative error (MRE) of 10 predicted values for sample 3# are merely 5.94% and 4.73%, respectively. [Conclusions]: This demonstrates that the combination of PLSR algorithm and femtosecond LIBS exhibits high analytical accuracy and stability for samples. This finding can provide significant reference for practical applications of femtosecond LIBS technology in the quantitative analysis of U content in uranium polymetallic ores.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-30
Abstract：在核辐射测量中，受限于测量系统本身以及测量环境的干扰，脉冲畸变不可避免，如果无法准确估计这类脉冲的参数将会降低能谱的分辨性能。本文提出将六种轻量级神经网络模型用于畸变脉冲的参数预测，预测对象包括脉冲幅度参数和畸变时间参数。以预定义的数学模型生成的畸变脉冲为基础数据集，经数字三角整形得到模型训练所需的数据集。模型性能评估结果表明，传统的数字整形法虽然在时间参数预测上具有绝对优势，但在幅度参数预测中却受到脉冲畸变的限制，无法获得准确的幅度预测结果。在对包括UNet在内的六种神经网络模型进行参数预测性能评估时，UNet模型在测试集上获得了最低的相对误差，其中幅度参数的相对误差约为0.57%，时间参数的相对误差为3.51%。在信噪比实验中，探讨噪声对具有优秀参数预测性能的UNet模型与CNN-LSTM模型的影响，进一步证明了UNet模型优秀的抗噪性能。
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-27
Abstract： Abstract Background : The operation of marine reactors and floating nuclear power plants is challenged by the thermal fluctuation of heat transfer surfaces caused by oceanic motion. The pyroelectric effect of lithium tantalate (LT), a material that changes its spontaneous polarization with temperature variations, has the potential to influence the wettability of surfaces, thereby improving heat transfer performance. Purpose : This study aims to prepare LT coatings with controlled pyroelectric properties and to investigate the mechanism by which these properties can regulate the wettability of surfaces, thereby enhancing heat transfer efficiency in two-phase systems. Methods : The sol-gel method was used to achieve the controlled synthesis of LT, and the pyroelectric effect and mechanism of wettability modulation were investigated by the change of hydroxyl radical. Results : The results indicate that the crystallinity, particle size, and thickness of the coatings can be regulated by adjusting the synthesis parameters and the particle size of LT increases with increasing annealing temperature. The pyroelectric characteristics are significantly influenced by the thickness and particle size of the coatings, with increased thickness and decreased particle size both contributing to enhanced pyroelectric performance. Fluorescence spectroscopy analysis shows that the hydroxyl radical concentration of LT increases during the heating process, and it also confirms that LT has the ability to regulate the hydroxyl radical concentration when undergoing heating and cooling cycles. Conclusions : In conclusion, LT coatings have temperature-dependent wettability in two-phase system with variable temperature.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-24
Abstract： [Background]: In ESR dating of old fossils, the Double Saturation Exponential (DSE) function is often used for the equivalent dose (DE) determination, it generally requires more than 15 dose points and the maximum irradiation dose (Dmax) of ＞20kGy to ensure the fitting accuracy, which limit the practical application of dating old fossils by ESR method with insufficient sample size. [Purpose]: This study attempts to explore the feasibility and reliability of using the single saturation exponential (SSE) fitting function to fit fewer dose points with lower Dmax to obtain the DE values of the fossil teeth from pre-Early Pleistocene sites, and compared with the ones determined by DSE function of 17 fossil samples from the late Miocene to the early Pleistocene. [Methods]: First, we compared the DE values obtained by three fitting functions (DSE, SSE and EPL-exponential plus linear) by the additional dose method. Then, the influence of different Dmax on the DE results is investigated. Finally, the artificially regenerative dose-response curves fitted by the three functions with the weighted mean ESR signal intensity of the dose points were compared. [Results]: This study showed that (1) the DE results of SSE and EPL functions are systematically higher than those of DSE function under the same condition as Dmax=50kGy and 15 dose points, and the fitting accuracy of former two functions is better than that of DSE function in general. (2) For samples with DE＞4500Gy and DE＜4500Gy, the results of SSE and DSE are basically consistent within the error range under the conditions of Dmax≥6.5*DE and 1.3*DE＜Dmax＜2.2*DE, respectively, which can provide the recommended dose value of Dmax for samples with DE＞2000Gy when using SSE function. (3) For fossil samples with DE＜4500Gy, the SSE function can be used to fit the 11 dose points with Dmax≤10kGy, and the DE results are generally consistent with the DSE function within the error range. (4) The artificially regenerative dose-response curves of the weighted mean ESR signal intensity of the sample dose points showed that the DSE function had the best goodness of fit at 15 dose points, and the goodness of fit between the SSE and DSE function tended to be close at 11 dose points. [Conclusions]: Based on our study, it is viable to use SSE function to perform DE fitting on old fossil samples under certain Dmax/DE conditions. In the further study, we will try the fragmental analysis of the fossil teeth for DE determination and to establish the standard growth curve of old fossils established by the DE values obtained by SSE and DSE functions and compared with conventional additive dose method to explore its feasibility.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-19
Abstract： [Background]: Transparent protective materials are an important component of nuclear radiation protection equipment and a key factor in reducing radiation damage to the eye lenses of radiation workers. [Purpose]: Gadolinium-containing polymethyl methacrylate (PMMA) were prepared by intrinsic polymerization, and the shielding properties of PMMA with different Gd(MA)3 content against neutron and gamma rays were studied. [Methods]: The neutron and gamma shielding performance of gadolinium-containing PMMA was measured by Cf-252 neutron source and Am-241 gamma source, respectively. MCNP simulation was also employed to study the neutron shielding performance of PMMA containing Gadolinium [Results]: The results showed that with the increase of Gd(MA)3 content, the shielding properties of the PMMA against Cf-252 neutrons (moderated by 12cm polyethylene) continuously improved. However, when the Gd(MA)3 content exceeds 10%, the increase in neutron shielding performance was not significant, whereas the shielding performance against gamma rays continues to improved. The PMMA containing 10% and 30% Gd(MA)3 has absorption cross-sections for Cf-252 neutrons and linear attenuation coefficients for 59.5 keV (Am-241) gamma rays of 0.79 cm-1 and 2.10 cm-1, respectively. In addition, with the thickness of the PMMA increases, its neutron shielding performance increases exponentially, 90.2% of Cf-252 fast neutrons were shielded by PMMA with a thickness of 10 cm and a Gd(MA)3 content of 10%. [Conclusions]: The addition of gadolinium to the PMMA could effectively enhances its shielding properties against thermal neutrons and gamma rays, and it maintains good visible light transmittance and to some extent improves the heat resistance of the material, but its mechanical strength is reduced. The results of this study provide valuable information for the development of apparent neutron/gamma shielding equipment.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-18
Abstract： [Background]: Transparent protective materials are an important component of nuclear radiation protection equipment and a key factor in reducing radiation damage to the eye lenses of radiation workers. [Purpose]: Gadolinium-containing polymethyl methacrylate (PMMA) were prepared by intrinsic polymerization, and the shielding properties of PMMA with different Gd(MA)3 content against neutron and gamma rays were studied. [Methods]: The neutron and gamma shielding performance of gadolinium-containing PMMA was measured by Cf-252 neutron source and Am-241 gamma source, respectively. MCNP simulation was also employed to study the neutron shielding performance of PMMA containing Gadolinium [Results]: The results showed that with the increase of Gd(MA)3 content, the shielding properties of the PMMA against Cf-252 neutrons (moderated by 12cm polyethylene) continuously improved. However, when the Gd(MA)3 content exceeds 10%, the increase in neutron shielding performance was not significant, whereas the shielding performance against gamma rays continues to improved. The PMMA containing 10% and 30% Gd(MA)3 has absorption cross-sections for Cf-252 neutrons and linear attenuation coefficients for 59.5 keV (Am-241) gamma rays of 0.79 cm-1 and 2.10 cm-1, respectively. In addition, with the thickness of the PMMA increases, its neutron shielding performance increases exponentially, 90.2% of Cf-252 fast neutrons were shielded by PMMA with a thickness of 10 cm and a Gd(MA)3 content of 10%. [Conclusions]: The addition of gadolinium to the PMMA could effectively enhances its shielding properties against thermal neutrons and gamma rays, and it maintains good visible light transmittance and to some extent improves the heat resistance of the material, but its mechanical strength is reduced. The results of this study provide valuable information for the development of apparent neutron/gamma shielding equipment.
Key words PMAM; Gadolinium; Neutron protection; Gamma protection; Transparent materials
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-13
Abstract：在核辐射测量中，受限于测量系统本身以及测量环境的干扰，脉冲畸变不可避免，如果无法准确估计这类脉冲的参数将会降低能谱的分辨性能。本文提出将六种轻量级神经网络模型用于畸变脉冲的参数预测，预测对象包括脉冲幅度参数和畸变时间参数。以预定义的数学模型生成的畸变脉冲为基础数据集，经数字三角整形得到模型训练所需的数据集。模型性能评估结果表明，传统的数字整形法虽然在时间参数预测上具有绝对优势，但在幅度参数预测中却受到脉冲畸变的限制，无法获得准确的幅度预测结果。在对包括UNet在内的六种神经网络模型进行参数预测性能评估时，UNet模型在测试集上获得了最低的相对误差，其中幅度参数的相对误差约为0.57%，时间参数的相对误差为3.51%。在信噪比实验中，探讨噪声对具有优秀参数预测性能的UNet模型与CNN-LSTM模型的影响，进一步证明了UNet模型优秀的抗噪性能。
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-06-06
Abstract： In order to mitigate climate warming and achieve the 3060 goal, the state optimizes the industrial and energy structure. The efficient and clean utilization of coal is promoted and new energy is vigorously developed. On the premise of ensuring safety, nuclear power is actively and orderly expanded. Compared with traditional fossil energy, nuclear power has the advantage of clean, environmental protection and low consumption. However, the actual thermal efficiency of nuclear power plant is only about 33%. The rest heat is discharged into the environment, resulting in serious waste. Among them, the thermal discharge is discharged into the adjacent sea area and its heat has a thermal impact on the water environment. Therefore, the efficient utilization of thermal discharge residual heat can not only improve the energy utilization rate of nuclear power plants, but also reduce the thermal pollution to the water environment, which is conductive to energy conservation and emission reduction. In this paper, APROS software is used to simulate and analyze a comprehensive system for increasing temperature and production of greenhouse and indoor marine culture by using nuclear residual heat. The possibility of nuclear power and agricultural coupling system is demonstrated, which provides a scientific basis for the comprehensive utilization of nuclear residual heat in China.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-31
Abstract： Neutron-sensitive microchannel plates (nMCPs) have applications in neutron detection, including energy spectrum measurements, neutron-induced cross-sections, and neutron imaging. 10B-doped MCPs (B-MCPs) have attracted significant attention owing to their potential for exhibiting a high neutron detection efficiency over a large neutron energy range. Good spatial and temporal resolutions are useful for neutron energy-resolved imaging. However, their practical applications still face many technical challenges. In this study, a B-MCP with 10 mol% 10B was tested for its response to wide-energy neutrons from eV to MeV at the Back-n white neutron source at the China Spallation Neutron Source. The neutron detection efficiency was calibrated at 1 eV, which is approximately 300 times that of an ordinary MCP and indicates the success of 10B doping. The factors that caused the reduction in the detection efficiency were simulated and discussed. The neutron energy spectrum obtained using B-MCP was compared with that obtained by other measurement methods, and showed very good consistency for neutron energies below tens of keV. The response is more complicated at higher neutron energy, at which point the elastic and non-elastic reactions of all nuclides of B-MCP gradually become dominant. This is beneficial for the detection of neutrons, as it compensates for the detection efficiency of B-MCP for high-energy neutrons.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-31
Abstract：随着机器学习在中子-伽马（n-γ）甄别中的广泛应用，脉冲波形甄别中的特征子集选择成为一个值得关注的问题。经验方法、Random Forest分类和Logistic回归特征选择算法较为全面地完善了特征子集选择方法，核主成分分析（KPCA）则将特征子集进一步降维。实验结果表明，特征选择算法在微弱的核信号中表现不佳，错误率均达30%以上。经验方法中的特征子集选取范围则至关重要，特征子集“1-62”的错误率达到49.096%，远高于来自脉冲尾部的特征子集约1%的错误率。最优特征子集与尾积分对应的采样点不完全重合，但差异不大，尾积分对应的采样点可近似为最优特征子集。通过研究目前具有代表性的Random Forest分类、Logistic回归等特征选择算法和细致的经验方法，论文结果具有普适性，为特征子集的选择提供了进一步的理论支持。
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-22
Abstract： As a candidate material for fusion reactors, the main components of low activation ferrite steel (martensitic steel) are Fe and Cr. In actual working conditions, helium produced by fusion reactions will enter the material, causing microscopic defects and radiation damage, affecting the material's resistance to radiation (helium embrittlement phenomenon) and other physical properties. This article simulates the interface of Fe Cr alloy, the main material of the reactor, through first principles calculations. He atoms are doped at different substitution and interstitial sites, and the formation energy of each structure is calculated after optimizing its structure. The stability of He atoms at different positions on the Fe Cr interface is obtained. At the same time, by calculating the volume, it was found that He would cause significant lattice distortion at the Fe octahedral gap near the interface. Based on the analysis of electronic density of states, it is inferred that this is the result of the hybridization of He, Fe, and Cr atoms at specific positions, provide a theoretical basis for the next research on the microscopic defects and physical and chemical properties of nuclear grade stainless steel.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-16
Abstract： As a candidate material for fusion reactors, the main components of low activation ferrite steel (martensitic steel) are Fe and Cr. In actual working conditions, helium produced by fusion reactions will enter the material, causing microscopic defects and radiation damage, affecting the material's resistance to radiation (helium embrittlement phenomenon) and other physical properties. This article simulates the interface of Fe Cr alloy, the main material of the reactor, through first principles calculations. He atoms are doped at different substitution and interstitial sites, and the formation energy of each structure is calculated after optimizing its structure. The stability of He atoms at different positions on the Fe Cr interface is obtained. At the same time, by calculating the volume, it was found that He would cause significant lattice distortion at the Fe octahedral gap near the interface. Based on the analysis of electronic density of states, it is inferred that this is the result of the hybridization of He, Fe, and Cr atoms at specific positions, provide a theoretical basis for the next research on the microscopic defects and physical and chemical properties of nuclear grade stainless steel.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-08
Abstract： In this study, to efficiently remove Pb(II) from aqueous environments, a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent (NWF-serine) was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification. The effect of the absorbed dose was investigated in the range of 5–50 kGy. NWF-serine was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Batch adsorption tests were conducted to investigate the influences of pH, adsorption time, temperature, initial concentration, and sorbent dosage on the Pb(II) adsorption performance of NWF-serine. The results indicated that Pb(II) adsorption onto NWF-serine was an endothermic process, following the pseudo-second-order kinetic model and Langmuir isotherm model. The saturated adsorption capacity was 198.1 mg/g. NWF-serine exhibited Pb(II) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd, Cu, Ni, Mn, and Zn. Furthermore, NWF-serine maintained 86% of its Pb(II) uptake after five use cycles. The coordination of the carboxyl and amino groups with Pb(II) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-08
Abstract： As the main component of low-activation ferrite/martensite steel in candidate materials for fusion reactor, Fe-Cr alloy will enter the material and produce micro-defects under actual working conditions, which will cause radiation damage and affect the radiation resistance and other physical and chemical properties of the material. In this paper, the interface of Fe-Cr alloy, which is the main material of reactor, is simulated by first-principles calculation. He atoms are doped in different gap positions and substitution positions. The formation energy is calculated after structural optimization, and the stability of He atoms in different positions is obtained. At the same time, the calculation of volume shows that the lattice aberration of He at the interstitial position of Fe octahedron near the interface is caused by the hybridization of He, Fe and Cr atoms at specific positions.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-07
Abstract： The delayed γ-rays released from the debris of a high-altitude nuclear explosion ionize the atmosphere during transport in the high-altitude non-uniform atmosphere, causing a dramatic increase of the electron number density in the ionosphere, which affects the radio communication links through the ionosphere. In order to accurately describe the delayed γ-ray sources which evolves in time and space, we firstly establish a hydrodynamic model of the evolution of debris motion of a high-altitude nuclear explosion, then establish a hierarchical equivalent model of delayed γ-ray sources according to the debris parameters, and finally apply the Monte Carlo method to simulate the ionization effect of the delayed γ-rays in the high-altitude non-uniform atmosphere. Because the debris shape continuously evolves with time, a method of stratified sampling of the radiation source is built to obtained the initial positions of the delayed γ-rays. Due to the atmosphere density decaying exponentially with height, the mass thickness sampling method is used to simplify the calculation model. The results show that the ionization intensity and range of delayed γ-rays are significant influenced by the shape of the debris. The ionization range of delayed γ-rays in a megaton level high-altitude nuclear explosion can reach more than a thousand kilometers. When the equivalent increases with a constant explosion height, the debris height and horizontal radius increases, the ionization range and intensity of the atmosphere caused by the delayed γ-rays increase. When the burst height increases with a constant equivalent, the debris height and horizontal radius increases, the ionization range caused by the delayed γ-rays increases, while the ionization intensity decreases.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-07
Abstract： Smart-Cut technology is a technique of exploiting both ion implantation and wafer bonding to transfer ultrathin single-crystal layers from a donor substrate to a receiving substrate. In advanced microelectronic systems, as one of the important technical means of heterogeneous integration for semiconductor materials, Smart-Cut technology has been widely concerned by academia and industry. Smart-Cut technology is the process of implanting H+, He+ ions or co-implantation them into the surface of semiconductor materials, and adjusting the implantation parameters (energy, temperature, dose, dose rate, ion implantation sequence, etc.). After the bonding of implanted semiconductor material and substrate at low temperatures, annealing (temperature, time, rate) that generates microcracks parallel to the surface is performed to achieve layer transfer. In this paper, the research progress of the Smart-Cut technology used in the first-, second-, third- and fourth-generation semiconductors in the past two decades is summarized. The microstructure and microcracks nucleation and growth mechanisms are analyzed. The reasons for the exfoliation thresholds of different semiconductors are discussed. The paper is helpful for understanding the application of Smart-Cut technology used in the fabricating of semiconductor devices.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-06
Abstract： Background Stepper motor driver is the main equipment of the cabinet of Absorption Sphere Shutdown System of HTR-PM, which can control the stepper motor to act according to the preset value, if it works abnormally due to the influence of interference, it will cause the stepper motor to run unexpectedly, which may cause the risk of the absorption sphere falling or refusing to fall by mistake and affect normal operation or nuclear safety of Nuclear Power Plant. Purpose The stepper motor driver adopts pulse width modulation(PWM) technology, accepts the weak current pulse instruction, converts the input 220VAC rectification into direct current（DC）, and then inverts and modulates it into a high-voltage pulse signal to control the rotation angle and running speed of the stepper motor, and the output of pulse width modulation contains a large number of high-order harmonic components, which causes pollution and impact to the power grid and grounding system, and causes interference to the weak current control signal in the system and causes abnormal operation of the stepper motor. In this project, the stepper motor driver is not only the source of interference, but also the object of interference, and there are inherent difficulties in the anti-interference design, through research and analysis, a scientific and reasonable anti-interference scheme is formulated, which effectively reduces the pollution and impact of the power grid and grounding system caused by the PWM mechanism, and avoids the abnormal operation of the stepper motor driver. Methods Through theoretical calculations and practical tests, this study thoroughly studied the transmission path, mechanism and influence degree of interference caused by PWM, and designed customized optoelectronic isolation equipment. Dedicated reactor and filter are arranged on the corresponding interference source transmission path, which effectively blocks the interference propagation and suppresses the influence of interference, which conforms to the unique working
environment of the cabinet of the absorption sphere shutdown drive mechanism. Results The anti-interference design scheme of the cabinet project of the absorption sphere shutdown drive mechanism effectively suppresses the impact of interference on the system, ensures the accurate and stable operation of the stepper motor driver, and realizes the angle deviation of the stepper motor within 1°for every 20*360° operation, which effectively prevents the risk of malfunction of the stepper motor and improves the reliability of the system operation. Conclusions This research scheme has a good guiding significance for the anti-interference design of various control systems of the same type, and has certain promotion significance.
Peer Review Status:
Awaiting Review
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-02
Abstract： Abstract: [Introduction] To solve the contradiction between the instability of nuclear fusion heating power output and the smooth op-eration of steam turbine generators, CFETR nuclear fusion power plants can use heat storage technology to reduce the peak and valley power output of nuclear fusion reactors. There are various types of thermal storage technologies, and it is urgent to compare their ap-plicability to nuclear fusion power plants. [Method] The article selected the parameters of helium cooled ceramic breeder cladding in nuclear fusion reactors as the boundary conditions for thermal storage technology. By evaluated the applicable temperature range of thermal storage technology, three potential thermal storage technologies for CFETR nuclear fusion power plants were preliminarily ana-lyzed, and their costs were preliminarily predicted. [Result] The three major types of heat storage technologies can all select heat storage media suitable for the temperature parameters of the helium cooled breeder blanket in CFETR nuclear fusion power plants. However, chemical heat storage has the potential to be applied in CFETR nuclear fusion power plants due to the temperature difference between its heat absorption and release, which is not conducive to the stability of the system and causes energy loss. Sensible heat storage technolo-gy and phase change heat storage technology have smaller temperature differences between their heat absorption and release. The pre-liminary economic analysis results show that the cost of phase change heat storage is the lowest, followed by molten salt heat storage, and the use of silicon bricks as the heat storage medium in solid-phase sensible heat storage technology. The use of cast steel as the heat storage medium in solid-phase sensible heat storage technology has the highest cost. [Conclusion] In thermal storage technology, molten salt thermal storage technology, phase change thermal storage technology, and solid-phase sensible thermal storage have the prerequisites for application in helium cooled breeder cladding in nuclear fusion power plants. Molten salt thermal storage technology has a high de-gree of maturity and has a large number of engineering applications, with a cost between phase change thermal storage and solid-phase sensible thermal storage, and has great potential for application. The cost of phase change heat storage is the lowest, and the parameters are suitable for nuclear fusion power generation. However, its technological maturity is relatively low, and it is expected to become a focus of future research.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-01
Abstract： This article addresses the high-efficiency and high-precision requirements for quality inspection of nuclear fuel rod welds. It designs and implements an online automated evaluation system. The system adopts a B/S architecture and integrates advanced AI technology to achieve real-time image acquisition, management, and intelligent analysis of fuel rod welds. The front end of the system utilizes Electron.js, React, and Ant Design frameworks, while the back end is based on Spring Cloud and Docker technologies, ensuring ease of operation and system stability. Through integrated AI models, the system effectively identifies weld defects, enhancing inspection accuracy and production efficiency. The successful implementation of this system provides robust support for the safe operation of nuclear power plants and quality control in the nuclear energy industry, laying the foundation for future developments in automated inspection technology.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-04-29
Abstract： Neutron porosity measurement with drilling, by measuring thermal neutron counts to evaluate the formation deceleration length and thus obtain the formation porosity, is an important method for formation reservoir evaluation and has been widely used in the exploration and development of complex oil and gas fields. The D-T source neutron porosity logging instrument with drilling consists of a pulsed neutron source and a multi-detector. The neutron porosity response is affected by the instrument structure and measuring method of the instrument, while factors such as borehole parameters, fluid parameters and stratigraphy can affect the neutron field distribution around the tool and the logging response. In this paper, Monte Carlo simulation methods are used to study the effects of different drill structures and instrument designs, environment factors of instrument measurements and formation parameters on the neutron flux distribution and porosity response. The analysis shows that the detector count increases with the side slotted design, but the formation porosity sensitivity is only 0.36 times that of the infiltration channel wrap-around design. The drill size is the main controlling factor for the impact of the measurement environment. The analysis results about formation environmental, including formation lithology, mud content and formation water mineralization, show that the influence of lithology on the measurement results is almost constant. In low porosity, the mud content is 2.9 times that of the formation water mineralization, and in high porosity, it is 1.48 times. Therefore, the mud content of the formation is the dominant controlling factor in the influence of the stratigraphic environment.
Hits
Hits
Downloads
Comment
YES