最新刊期
卷 44 ， 期 10 ， 2021
- “中国原子能科学研究院研制的可移动式X射线照射装置，通过蒙特卡罗软件建模，成功验证了现场校准环境散射辐射计算模型，为X射线散射辐射修正系统研究提供数据支持。”摘要：BackgroundFixed X-ray and γ-ray radiation dosimeters are important tools for evaluating the operational status of equipment and personnel safety. On-site calibration method of this type of instrument has gradually become a research hotspot. A mobile X-ray irradiation device is developed by the Division of Radiation Metrology of China Institute of Atomic Energy for field calibration.PurposeThis study aims to build the computational model of this mobile X-ray irradiation device for simulation, and to carry out experimental verification of environmental scattered radiation for on-site calibration of these dosimeters.MethodsFirstly, a simplified model of the irradiation device and environment with the same scale was established by Monte Carlo N Particle Transport Code (MCNP) to determine calculation method of the environmental scattered radiation. Secondly, the model verification work was carried out under the basic scenario conditions were analyzed, and the model size was adjusted by analysis of the main factors affecting the results. Finally, the improved model was verified by experiments.ResultsThe half opening angles of aperture model are finally determined to be 5°, 8°30′ and 10°20′. The relative deviation between the calculated results of the improved model and the experimental results were -11.6% ~ 9.3% in the radiation quality index range of N100~N200.ConclusionsA significant amount of experimental measurement time can be saved by this computational model, and it is feasible to use the validated model to provide training data for the development of a machine learning-based in-situ X-ray scattering radiation correction system.关键词：Mobile X-ray irradiation device;Scattering radiation;On-site calibration;Monte Carlo
- 469
- |
- 69
- |
- 0
发布时间：2024-10-25
ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS
- “铁基材料Cl吸附腐蚀行为研究取得新进展，揭示了辐射-含氯地下水耦合环境中铁基材料腐蚀的微观机理，为高放废物包装容器选材提供指导。”摘要：BackgroundThe packaging container is critical to the safe disposal of high-level radioactive waste. The study of Cl adsorption and corrosion behavior of iron-based materials is of guiding significance for the selection of packaging materials for high-level radioactive waste.PurposeThis study aims to clarify the effect of Cl adsorption on the corrosion of iron-based materials in radiation environment.MethodsBased on the first principle of density functional theory, the separation and co-adsorption models of Cl on Fe(100) surface were constructed. Parameters, such as ariations of adsorption energy, Fe-Cl bond length and electronic structure, etc., in the process of Cl adsorption were studied by using Medea-VASP code. Effects of water radiation decomposition products (O, H and OH free radicals) on the stability of Cl adsorption were analyzed emphatically.ResultsThe calculation results show that the length of Fe-Cl bond is shortened by the absence of surface atoms and the existence of free radicals. In the four co-adsorption systems, the adsorption energies of Fe/(Cl-H2O), Fe/(Cl-H), Fe/(Cl-OH) and Fe/(Cl-O) decrease successively, while the charge transfer number of Bader increase successively.ConclusionsAdsorption of Cl on the defect Fe surface is more stable in the radiation environment, and the radiation decomposition products of H2O promote the adsorption of Cl on the defect Fe(100) surface, revealing the microscopic mechanism of corrosion of iron-based materials in the radiation-chlorine-containing groundwater coupling environment.关键词：HLW-packaging container;Radiation decomposition;Defect iron surface;Cl adsorption;First principles
- 458
- |
- 39
- |
- 0
发布时间：2024-10-25
NUCLEAR CHEMISTRY, RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE
- “在细胞电穿孔技术领域，专家提出了新型脉冲发生器结构，可实现双极性脉冲电压输出，为细胞电穿孔实验提供解决方案。”摘要：BackgroundCell electroporation technology under pulsed electric field has been widely used in water treatment, food sterilization, tissue ablation and other applications. Different electroporation applications have different requirements for the pulse waveform.PurposeThis study aims to propose a new pulse generator structure consisting of a special full bridge (FB) module and multiple half bridge (HB) modules to generate bipolar pulse voltages, stepped waves and combination of narrow and wide pulses can also be realized by only changing the switching sequence.MethodsFirst of all, the structure and working principle of novel circuit were elaborated. Then, a main circuit structure composed of 1 full-bridge module and 4 half-bridge modules composed of 12 switches were designed and implemented. Bipolar pulse voltages, stepped waves and combination of narrow and wide pulses were realized by only changing the switching sequence. Finally, verification of the power supply for cell electroporation experiments was carried out in the potato tuber treatment experiment. [ResultsandConclusions] When each level of capacitor is charged at 220 V, bipolar pulse voltage output with ±2 kV and adjustable pulse width of 1~10 μs is realized. Furthermore, the output of a unipolar 9-level step voltage and a combination of wide and narrow pulses are achieved by controlling the switching sequence. Experiment of potato tuber treatment verified the feasibility of this pulse generator.关键词：Pulse generator;Bipolar;Step wave;Electroporation
- 421
- |
- 47
- |
- 0
发布时间：2024-10-25 - “在地层元素测井领域，研究人员利用MCNP软件研究了影响溴化镧探测器效率的因素，并进行了无源全能峰效率刻度，为实验室效率刻度提供参考。”摘要：BackgroundActive efficiency calibration of radiation detector requires the multiple standard radioactive sources with different energies, and the measurement condition of the standard sources need to be consistent with sample sources. Due to the limitation of these experimental conditions, it is difficult to achieve efficiency calibration of detectors effectively in ordinary laboratories.PurposeThis study aims to solve the above problems by simulation and experimental test.MethodsFirst of all, Monte Carlo software MCNP (Monte Carlo N Particle Transport Code) was used to explore the influences of detection efficiency for a lanthanum bromide scintillation detector corresponding to the simulated energy of 0.662 MeV of 137Cs source. Influencing factors such as Al shell thickness, MgO reflector thickness and crystal size of LaBr3:Ce (ø3.18 cm×10.16 cm) detector on full-energy peak efficiency were calculated. Then, passive full-energy peak efficiency calibration of the detector was carried out by the MCNP, and the simulation results were compared with the ones of theoretical calculation and measurement.ResultsThe full-energy peak efficiency decreases with the increase of thicknesses of the Al shell in end-face and the MgO reflector, and thickness of the cylindrical Al shell has little effect on that. The full energy peak efficiency raises with the increase of the crystal length and radius of the detector, and the effect of the radius on the full-energy peak efficiency is more obvious than that of the length. The errors between the simulation and the theoretical calculation as well as the measurement results are within 7% and 6%, respectively.ConclusionsThe accurate of simulation results proves the correctness of efficiency calibration in this study which provides reference for the laboratory to perform passive efficiency calibration.关键词：MCNP simulation;Influencing factors;Full energy peak efficiency;Efficiency calibration
- 472
- |
- 52
- |
- 0
发布时间：2024-10-25
NUCLEAR ELECTRONICS AND INSTRUMENTATION
- “在放射性气溶胶监测领域，研究者对不同滤膜的吸附性能进行了实验，发现MCEM滤膜探测效率最高，疏水性PTFE滤膜对α能谱测量拖尾影响最小，为取样滤膜的最优选取提供参考。”摘要：BackgroundSampling filter membrane is an important part of the continuous monitoring system for radioactive aerosols. The performance of the sampling filter membrane directly affects detection efficiency of the system. In addition, tailing effect in α spectra increases the difficulty of identifying nuclides, reduces the accuracy of aerosol measurement, and elevates the minimum detectable activity.PurposeThis study aims to find a sampling filter membrane with high detection efficiency, small α spectrum tailing and the pore size suitable for actual environmental measurement.MethodsThe detection efficiency and spectrum tailing performance of the three most commonly used filter membranes at present, i.e., mixed cellulose ester membrane (MCEM), hydrophobic polytetrafluoroethylene (PTFE) and polypropylene (PP) filter membranes, were tested under different radon concentrations and various pore sizes. Then, based on obtained data of the tests, the comprehensive evaluation was performed on their adsorption performances to determine the optimal sampling filter membrane.ResultsThe results show that the MCEM filter membrane has the highest detection efficiency and the hydrophobic PTFE filter membrane has the least tailing effect in the three kinds of filter membranes. In comparison of other pore sizes under different radon concentrations, the MCEM filter membrane or hydrophobic PTFE filter membrane has the highest detection efficiency when its pore size is 0.45 µm, which is close to the maximum particle size of natural radioactive aerosols. No obvious effect of the pore size of the filter membrane is observed on the α spectrum tailing. In addition, for one filter membrane with the same pore size, the detection efficiency decreases with the increase of aerosol concentration and vice versa.ConclusionsThis study provides a useful reference for the optimal selection of filter membranes for natural radioactive aerosols under various conditions.关键词：Radioactive aerosol;α spectrum tailing;Filter membrane;Detection efficiency
- 405
- |
- 50
- |
- 0
发布时间：2024-10-25 - “在微电子器件辐射效应研究领域，中国原子能科学研究院专家建立了中能质子辐照试验装置，通过蒙特卡罗仿真模拟，验证了该装置适合开展质子单粒子效应实验研究。”摘要：BackgroundBased on the 100 MeV proton cyclotron in the China Institute of Atomic Energy (CIAE), the middle-energy proton irradiation test facility was established and several proton single event effect (SEE) experimental study of micro-and nano-electronic devices were carried out. The proton beam striking the device under test (DUT) is contaminated with neutrons generated as a result of protons interacting with the devices between the accelerator and the DUT. The quality of the proton beam directly affects the effectiveness and accuracy of the experimental cross section of proton SEE.PurposeThis study aims to simulate the proton beam distribution and secondary neutron for intermediate energy proton SEE test.MethodsFirst of all, the geometric model of the proton beam transmission line was established. Then, the Monte Carlo N Particle Transport Code (MCNP) was employed to simulate the proton beam of 100 MeV incidence energy. Results were reduced to the case of single proton incidence, the energy and fluence distribution of proton beams on the sample irradiation plane were obtained, as well as the energy and fluence distribution of the secondary neutrons. Finally, influence of secondary neutrons on the experimental cross section of proton single event effect was analyzed according to the ratio of neutron fluence to proton fluence.Results & ConclusionsSimulation results show the effect of secondary neutrons on the cross section of proton single event effect is insignificant, and the medium energy proton irradiation test facility in CIAE is very suitable for the experimental study of proton single event effects.关键词：Single event effect;Proton radiation test;Secondary neutron
- 394
- |
- 43
- |
- 0
发布时间：2024-10-25
NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH
- “在核电站耐事故燃料领域，专家利用COMSOL软件，通过Java算法模拟孔隙特征，为提高碳化硅复合包壳力学性能提供新思路。”摘要：BackgroundSilicon carbide composite has good stabilities in heat, mechanics and chemistry, therefore, become an important candidate cladding for accident tolerant fuel of nuclear power plant. The silicon carbide composite prepared by existing manufacturing process contains a certain amount of pores, which adversely affect mechanical properties of the composite cladding.PurposeThis study performs to investigate effects of pore characteristics on silicon carbide cladding equivalent Young's modulus.MethodsFirstly, the APP development module in finite element analysis software COMSOL was adopted to implement the random generation algorithm of pores by Java programming. Silicon carbide composite cladding models with different pore characteristics were generated by algorithmic presetting porosity, distribution and size of pores in the silicon carbide composite. Then, the equivalent Young's modulus of the corresponding SiC composite cladding was calculated quantitatively to investigate the effect of different pore characteristics on equivalent Young's modulus.Results & ConclusionsThe computational results show that the silicon carbide cladding equivalent Young's modulus can be calculated accurately by the COMSOL software. The equivalent Young's modulus decreases linearly with the increase of porosity when the distribution and size of the pores are constant whilst little effect of the distribution and size of pores is shown on the equivalent Young's modulus when the porosity is constant.关键词：Silicon carbide composite cladding;Pore;Pore characteristics;COMSOL;Equivalent Young's modulus
- 379
- |
- 31
- |
- 0
发布时间：2024-10-25 - “液态熔盐堆后处理效率对燃料循环性能影响显著，裂变产物分离效率提高可节省低富集铀添加量，降低重金属摩尔比，提高燃耗深度。”摘要：BackgroundChemical post-processing is one of the important characteristics of molten salt reactors (MSR). The post-processing efficiency will affect the neutron performance of core fuel cycle. Therefore, it is necessary to explore the influence of different aftertreatment schemes on fuel cycle performance.PurposeThis study aims to evaluate the neutron characteristics of different post-processing schemes for core fuel cycle of MSR.MethodsBased on the 65 MW MSR core structure with bath fuel post-processing mode, the neutron properties of excess reactivity, low enriched uranium (LEU) feeding inventory, heavy metal mole fraction, and burnup of different reprocessing schemes were analyzed by using self-developed MSR post-processing coupling program.ResultsThe results show that the separation efficiency of fission products has an obvious impact on the neutron performances. When the separation efficiency of fission products is increased from 0 to 100% during 40-a operation of this MSR, the LEU feeding inventory can be saved by about 520 kg whilst the heavy metal mole fraction is reduced by about 9.6% and the burnup is increased by about 10%. Compared with fission products, the removal of transuranium (TRU) has less influence on neutron characteristics due to their fission ability and low inventory.ConclusionsTheoretical simulation calculation in this study provides a reference for the choice of the nuclide removal and its efficiency for chemical post-processing.关键词：Chemical post-processing;MSR;Separation efficiency;Fuel cycle
- 384
- |
- 36
- |
- 0
发布时间：2024-10-25 -
Investigation on leakage and solidification characteristics of fluorides in molten salt reactor AI导读
“在熔盐反应堆安全领域，专家基于CFD模型，研究了氟盐泄漏扩散和凝固现象，提出了收集与隔热方案，为解决泄漏问题提供解决方案。”摘要：BackgroundThe high temperature molten salt is generally used as the heat transfer medium in molten salt reactor (MSR), and the molten salt leakage accident is a crucial issue for the safety of reactor operation.PurposeThis study aims to investigate the characteristics of molten salt leakage and solidification and to provide effective measures to reduce the risk of molten salt leakage accidents.MethodsBased on the computational fluid dynamics (CFD) model, the leakage of molten fluoride salt flow onto the quartz sand and subsequently phenomena including permeation, spreading, melting and solidification were studied by using ANSYS FLUENT code.ResultsThe results show that the molten salt diffuses both vertically and horizontally after contacting the sand, due to the cooling of ambient and temperature gradient of the sand, the bottom of molten salt in the sand will freeze, making the vertical permeation depth stabilized and the liquid molten salt will only spread horizontally on the top surface of sand. For a certain period of molten salt leakage, the higher the molten salt temperature and leakage flow rate, the larger the maximum diffusion radius of horizontal detection and permeation depth in vertical direction.ConclusionsBased on above analysis, a method with respect to the collection and thermal insulation of high temperature molten salt under leakage accident is proposed, and analyzed to verify the effectiveness of the method.关键词：Molten salt reactor;Fluorides;Leakage;Solidification- 386
- |
- 30
- |
- 0
发布时间：2024-10-25 - “在铅铋反应堆领域，专家开发了环形燃料热工水力分析程序，探索了最佳排列方式，为实现反应堆小型化和经济性提高提供解决方案。”摘要：BackgroundAnnular fuel can significantly increase the power density of the lead-bismuth reactor core, which is of great significance to realize miniaturized design of the reactor and fuel economy improvement.PurposeThis study aims to develop an annular fuel calculation program to obtain key thermal and hydraulic parameters, so as to obtain the optimal arrangement of annular fuel under different objectives.MethodsFirst of all, based on the closed parallel multi-channel model and quantum genetic algorithm, the thermal-hydraulic analysis program of the lead-bismuth fast reactor annular fuel was developed through the decoupling calculation of flow distribution and heat distribution. Secondly, five parameters, i.e., the maximum temperature of the fuel pellet, the maximum temperature of the fuel cladding, the temperature difference between the inner and outer outlets, the pressure drop, and the core power, were taking as the evaluation indicators, and the multi-objective comprehensive evaluation method was used to investigate the optimal layout of the annular fuel assembly. [Result&ConclusionsThe results show that the error between the developed lead-bismuth fast reactor annular fuel thermal-hydraulic analysis program and the similar program developed by Nanyang Technological University in Singapore is within 3%. On the basis of ensuring the calculation accuracy, the decoupling calculation of flow distribution and heat distribution significantly improves the computation efficiency of the program. Results of the annular fuel arrangement show that 18×18 arrangement is a better choice from a safety point of view whilst the 16×16 arrangement is the best choice from the economic point of view. Considering comprehensive safety and economy, the 19×19 arrangement has better safety performance and economy.关键词：Lead-bismuth cooled fast reactor;Annular fuel;Multi-objective optimization;Optimal arrangement
- 398
- |
- 29
- |
- 0
发布时间：2024-10-25 - “在反应堆保护系统可靠性评估领域，专家建立了动态故障树模型，采用动态二叉树法和拉丁超立方抽样，为提高系统可靠性提供解决方案。”摘要：BackgroundReactor protection system (RPS) has complex structure, numerous equipment, and continuous failure behaviors. The traditional static fault tree cannot accurately simulate the sequential failure behaviors of the RPS.PurposeThis study aims to obtain the failure probability of related system of RPS and the sensitivity of each component by simulating the sequential failure behaviors of RPS, and provide suggestions for the optimal design and optimization of RPS in the future.MethodsFirst of all, the dynamic fault tree (DFT) modeling tools was employed to model the reliability of the RPS, a dynamic binary tree method was applied to quantitative analysis of the DFT model. Then, the Latin hypercube sampling method was adopted to quantitatively analyze the uncertainty of the RPS failure probability, and compared with the traditional static fault tree method under the same conditions.ResultsSimulation results show that the failure probability with 0.95 confidence interval of RPS is 0.015 306~0.015 721. The two most sensitive components are the undervoltage drive card and the undervoltage relay.ConclusionsDFT can accurately simulate the reliability of RPS, and provide more accurate results, which is beneficial for optimization design in the future.关键词：Dynamic fault tree;Dynamic binary tree;Reliability;Latin hypercube sampling;Nuclear power plant
- 394
- |
- 31
- |
- 0
发布时间：2024-10-25 - “在核能供热领域，泳池式低温供热堆堆芯设计取得新进展，采用69盒组件方案，满足核设计准则，具有良好经济性和安全性。”摘要：BackgroundAs a kind of clean energy, nuclear energy has obvious advantages in reducing fossil energy consumption and pollutant emission. Nuclear energy can be used to provide not only electric energy, but also direct heating.PurposeThis study aims to design and optimize the pool type heating reactor core to make it with good economy and safety.MethodsThe core of heating reactor was located in the deep pool to make use of static pressure of the deep water for the outlet temperature elevating to meet the requirements of the heating system. The nuclear design of a core with 69 assemblies was applied to 400 MW pool-type heating reactor, it was characterized by truncated pressurized water reactor (PWR) assemblies, low power density, long cycle length, non-boron reactivity control mechanism. The gadolinium fuel rods was used to provide a part of backup reactivity. The burn-up of each cycle was calculated, and the important physical parameters were analyzed. Finally, the core design criteria were given, the loading mode of the core and the rod withdraw sequence were optimized.ResultsCalculation results show that the maximum discharge burnup is 31.10 GW·d·t-1 (U). The shutdown depth of the first and second shutdown system are 0.065 69 and 0.029 71, respectively.ConclusionsRelevant research and calculation in this study demonstrate that the core with 69 assemblies meets the relevant nuclear design criteria and has good economy and safety.关键词：Pool-type low temperature heating reactor;Nuclear design;Rod withdraw sequence
- 404
- |
- 41
- |
- 0
发布时间：2024-10-25 - “在核能领域，专家建立了铅冷快堆环形燃料元件热工模型，分析了关键因素，为提高堆芯功率密度提供解决方案。”摘要：BackgroundThe key factors affecting the thermal performance of the lead-cooled fast reactor (LFR) annular fuel are very important to improve the core power density of LFR.PurposeThis study aims to analyze those key factors and provide guidance for improving reactor core power density.MethodsFirstly, one quarter thermal analysis model of typical annular fuel element of lead cooled fast reactor was established, followed by the thermal resistance analysis of typical LFR annular fuel element to evaluate the key factors affecting its thermal performance. Secondly, four indicators, i.e., the temperature difference between the coolant outlet inside and outside the channel, the maximum temperature of annular fuel pellet, the position of adiabatic surface and the temperature difference between the inner and outer cladding, were used as evaluation criteria to analyze the influence of various factors on the thermal performance of the annular fuel element.ResultsThe thermal resistance analysis results show that the key factors affecting the thermal performance of LFR annular fuel element are gas gap width, cladding thickness and flow distribution ratio. Evaluation and analysis results indicate that temperature difference of coolant and the maximum temperature of annular fuel pellet can be significantly reduced by increasing the flow distribution ratio whilst slightly increasing the width of the outer gas gap and reducing the width of the inner gas gap can reduce the coolant outlet temperature difference and the average temperature difference between the inner and outer cladding. Changing the cladding thickness has no significant effect on the thermal performance of annular fuel element.ConclusionsStudying the key factors that affect the thermal performance of the LFR annular fuel has importance value for optimal design of the LFR core.关键词：LFR;Annular fuel;Thermal performance;Key influencing factors
- 374
- |
- 26
- |
- 0
发布时间：2024-10-25
NUCLEAR ENERGY SCIENCE AND ENGINEERING
- Address：2019 Jialuo Road, Jiading, Shanghai, China Postal code：201800
- Tel：021-39194977 Email：LHB@sinap.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 沪ICP备05005479号-1
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
- Total Visits：740143 Visits Today：885
0