最新刊期
      卷 45 ， 期 8 ， 2022

        SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS

      • “在催化剂领域，研究者探究了Pt/TiO2和Pt/SiO2催化剂在高温煅烧时金属-载体相互作用的影响，发现金属氧化物的还原性决定了载体锚定Pt原子的能力。”
        HE Wenxue,LI Hongmei,CHEN Wei,PAN Ya,XU Liuxin,SUN Zhihu,WEI Shiqiang
        Vol. 45, Issue 8, Article number: 080101(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080101
        摘要：BackgroundMetal-Support Interaction (MSI) modulates the activity, stability, and selectivity of catalysts by changing the morphology, composition, and electron density of metal particles. Such interactions in supported single-atom and cluster catalysts will be subjected to changes when the catalysts are treated at different temperatures and under different atmospheres.PurposeThis study aims to explore the effects of high temperature treatment on metal-support interactions of Pt/TiO2 and Pt/SiO2 catalysts with the coexistence of single atoms and clusters when heating and calcined in air at high temperature.MethodsThe structural evolutions of these two catalysts were investigated by a combination of high-resolution transmission electron microscopy (HRTEM), aberration-corrected high-angle annular dark-field transmission electron microscopy (AC-HAADF-STEM), synchrotron radiation technique X-ray absorption fine structure spectroscopy (XAFS), diffuse reflection Fourier transform infrared spectroscopy (DRIFT). XAFS characterization was conducted at Beijing Synchrotron Radiation Facility (BSRF) 1W1B beamline station to obtain information about the valence state and coordination environment of Pt/TiO2 at different calcination temperatures to confirm that Pt mono-atoms were immobilized on the support by Covalent Metal-Support Interaction (CMSI).ResultsAfter calcination at 700 ℃, all Pt species are presented as Pt single atoms in Pt/TiO2, while they agglomerate into larger particles in Pt/SiO2. The reducibility of metal oxides determines the ability of the support for anchoring single atoms of Pt: single atoms of Pt in TiO2 can be stabilized via the CMSI, and thus facilitate the dispersion of Pt atoms. On the contrast, CMSI cannot be formed between Pt and SiO2, resulting in particle sintering at high temperatures.ConclusionsThe formation of CMSI effect between metals and supports can be used as a general method for the preparation of reducible oxide supported high-loading, thermally stable single-atom catalysts.  
        关键词：Metal-support interaction;X-ray absorption fine structure;Diffuse reflectance fourier transform infrared spectroscopy;Covalent metal-support interaction   
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        发布时间：2024-10-25

        NUCLEAR CHEMISTRY, RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE

      • “广东某地岩洞型低中放废物处置库围岩对137Cs的吸附性能研究取得进展，为处置库建设提供数据支持。”
        YANG Gang,LIN Jingruolan,YANG Xueying,TUO Xianguo,PAN Yuelong,LIU Yu
        Vol. 45, Issue 8, Article number: 080301(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080301
        摘要：BackgroundAt present, radioactive waste is treated by deep geological treatment. Caves-type repository as a geological repository near the ground, are more and more international and domestic concern due to its nuclear safety, low environmental pollution and good economy. A cavern-type low and intermediate radioactive waste repository is being constructed in Yangjiang area of Guangdong province, China, the surrounding rock of the waste repository will be the main dispose material of nuclide 137Cs.PurposeThis study aims to investigate the adsorption performance of the surrounding rock of this cavern-type low and intermediate radioactive waste repository for 137Cs.MethodsFirst of all, series of characterization analysis, such as X-ray Fluorescence (XRF), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Brunauer-Emmett-Teller (BET), Barret-Joyner-Halenda (BJH) were employed to observe crystal structure and content of the surrounding rock of the waste repository. Irregular sheet-like structures stacked, the sheets in a compacted state, and the surface groups such as -OH, Si-O-Si, Si-O-Al, Si-O, etc. were shown to have good crystal structure and the highest SiO2 composite content. Then, the effects of time, pH value, solid-liquid ratio, initial radioactive activity concentration, and ions on the adsorption were investigated through static adsorption experiments. Finally, the adsorption kinetics and adsorption isotherm models were analyzed.ResultsThe results show that when the solid-liquid ratio is 5 g∙L-1, the initial radioactivity is 1 114.5 Bq∙L-1, the adsorption equilibrium time is 12 h, the equilibrium adsorption rate is 40.41%, and the equilibrium adsorption capacity is 90.07 Bq∙g-1. The adsorption rate increases with the increase of the solid-liquid ratio, and decreases with the increase of the initial radioactivity. The adsorption is inhibited under acidic conditions, but has little effect under neutral and alkaline conditions. Different ions inhibit the adsorption of 137Cs on the surrounding rock of the repository, and K+ has the greatest inhibition.ConclusionsThe adsorption of 137Cs by the surrounding rock is more in line with the pseudo-second-order kinetic model and the Freundlich adsorption isotherm model, providing the basic data for nuclear waste geological disposal engineering.  
        关键词：Cave-type repository;Surrounding rock;137Cs;Adsorption   
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        发布时间：2024-10-25

        NUCLEAR ELECTRONICS AND INSTRUMENTATION

      • “中国散裂中子源VSANS谱仪运动控制系统，采用步进电机、光栅和Beckhoff控制器，实现全闭环控制，重复定位精度优于±2μm，满足谱仪需求。”
        HE Yongcheng,XIAO Songwen,WANG Guangyuan,JIN Dapeng,ZHANG Yuliang,WU Xuan,XUE Kangjia,ZHU Peng,WANG Lin,ZUO Taisen,CHENG He
        Vol. 45, Issue 8, Article number: 080401(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080401
        摘要：BackgroundVery small angle neutron scattering (VSANS) instrument is a powerful tool for structure calibration.PurposeThis study aims to ensure the repeat positioning accuracy is better than ±2 μm for the moving parts of VSANS instrument at China spallation neutron source (CSNS).MethodsA prototype motion control system based on experimental physics and industrial control system (EPICS) software architecture was designed. The stepper motor was used to drive the movement of the displacement platform, the absolute optical encoder was applied to feedback of the real-time position of the displacement platform, and the Beckhoff embedded controller was employed to implement the full closed loop control of the position of the displacement platform.Results & ConclusionsThe test results show that the repeat positioning accuracy of this prototype motion control system is better than ±2 μm with high stability and high reliability, satisfying the needs of the VSANS instrument at CSNS.  
        关键词：CSNS (China Spallation Neutron Source);Very small angle neutron scattering instrument;Motion control system;EPICS (Experimental Physics and Industrial Control System)   
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        发布时间：2024-10-25
      • “在小型电子感应加速器国产化领域，研发了主控系统，实现了X射线产生，可应用于辐射型货物检查。”
        LIU Qi,WANG Haitao,LI Jinhai,CHEN Rui,CHEN Haisheng,WANG Renbo,TANG Bin
        Vol. 45, Issue 8, Article number: 080402(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080402
        摘要：BackgroundBetatrons are widely used in non-destructive testing, cargo and vehicle safety inspection systems.PurposeThis study aims to develop a mian control system of electron induction accelerator for the domestic production of small size betatron, and evaluate its imaging performance. Main control system was developed, including excitation power circuit, electron injection circuit, electron capture circuit and electron displacement circuit.MethodsThe inductor-capacitor parallel (LC) resonant circuit composed of excitation winding and capacitor bank was employed for excitation power circuit to generate a magnetic field that accelerates electrons steadily at the air gap of the electromagnet. The electron gun was applied to electron injection circuit for providing the electron source, and pulling the electron into the acceleration cavity. The electron capture efficiency was improved by a pulse assisted magnetic generated by field electron capture circuit, and the pulsed magnetic field was applied to the electron displacement circuit to instantaneously increase the central magnetic flux for deflecting the electron beam from the equilibrium orbit to the target to produce bremsstrahlung radiation.ResultsThe test results show that the generated X-ray steel penetration reaches 276 mm, the air wire detectability is 2 mm, the spatial resolution is 3 mm, and the contrast sensitivity meets the imaging requirements.ConclusionsThe developed control system and radiator can satisfy cargo and vehicles radiographic inspection system.  
        关键词：Betatrons;Bremsstrahlung;X-ray;Cargo and vehicles radiographic inspection system   
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        发布时间：2024-10-25
      • “PandaX合作组在锦屏地下实验室搭建双探头高纯锗γ谱仪，提升暗物质和中微子实验灵敏度2~4倍。”
        YAO Yukun,ZHANG Tao,CHENG Chen,SHEN Xun,LIU Jianglai,MENG Yue,QIAN Zhicheng,SI Lin,WANG Siguang,WU Mengmeng
        Vol. 45, Issue 8, Article number: 080403(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080403
        摘要：BackgroundIn rare decay experiments, for instance dark matter and neutrino experiments, rays produced by the radioavtive decay in detector material induce extra experiment background, the energy deposition would contaminate the concerned region. Accurately measuring radioactivity of detector materials, better understanding background source, and controlling experimental background are extremely important to improve sensitivity for those detections. With high energy resolution, flexibility for sample geometry and non-destructive processing for samples, high-purity germanium (HPGe) γ spectroscopy is a widely used ultra-low radioactive technology. The PandaX collaboration set up two high-purity germanium γ spectroscopies, so-call JP1 and JP2, in Jinping underground laboratory.PurposeThis study aims to improve the sensitivity of γ spectroscopies, precisely measure materials with lower radioactivity and screen lower radioactive material for dark matter and neutrino experiments by designing a gamma spectroscopy system with dual high-purity germanium detectors based on the existing JP1.MethodsTwo approaches, i.e., enhancing efficiency and suppressing background were adopted to improve the sensitivity of both HPGe detectors, and the Monto Carlo method was employed to analyze the efficiency and background source of JP1, hence the improved result of dual high-purity germanium detectors was estimated.ResultsFor different nuclides concerned in dark matter and neutrino experiments, the minimum detectable activity of dual high-purity germanium γ spectroscopy system is expected to improve by factor of 2~4. This new system can also measure the radioactivity with γ-γ coincidence method to improve the sensitivity for small size samples.ConclusionsDual high-purity germanium γ spectroscopy can improve sensitivity of factor 2~4 and apply to developing a new γ-γ coincidence method.  
        关键词：Dual HPGe detectors;Ultra-low background technique;Rare decay experiment;Deep underground laboratory   
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        发布时间：2024-10-25

        NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH

      • “在辐射安全防护领域，某型α放射性气溶胶监测仪受高氡背景干扰，研究显示，提高测量时长可降低干扰，确保监测结果可靠。”
        LU Xiaojun,HE Linfeng,MENG Lingchao,XIN Zhiwei,SONG Jiaban,HAN Gang,LI Xiaoshuang
        Vol. 45, Issue 8, Article number: 080501(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080501
        摘要：Backgroundα radioactive aerosol monitors are widely used for radiation safety protection in nuclear facilities, uranium mining and metallurgy, nuclear fuel processing, nuclear power plants, nuclear medicine, etc. High radon background will interfere with the accuracy of monitoring results.PurposeThis study aims to ensure the accuracy of its monitoring results by test its response and anti-radon interference performance.MethodsA certain type of alpha radioactive aerosol monitor was taken as the experimental object. 239Pu filter membrane reference sources were prepared as the measurement standard, and the standard radon chamber was used to provide different radon backgrounds and test the surface emissivity response, nonlinearity and judgment limit (95% confidence level).ResultsFirst, under the influence of high radon background, the response of surface emissivity is larger than that under normal background condition. In the same measurement period, the surface emissivity response in the continuous measurement mode is greater than that in the accurate mode, and the measurement accuracy in the accurate mode is higher than that of continuous mode. Second, when the surface emissivity of the 239Pu filter membrane is greater than 104 min-1·2πSr, the influence of high radon background is reduced, and the deviation of the surface emissivity response is less than 5.3% (only 2.9% in the accurate mode). Third, the duration of single measurement should be more than 60 min to ensure the reliability of monitoring results whilst the continuous sampling and measurement time should be longer than 24 h if there is a high radon background.ConclusionsThe research method has important reference value for the measurement, production and algorithm improvement of the α-radioactive aerosol monitor.  
        关键词：High radon background;Alpha radioactive aerosol monitor;Performance;influence   
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      • “在细胞膜通透性研究中，0.25% Triton X-100透膜效果优于4% SDS，处理时间10分钟，不影响染色结果和细胞形态。”
        LIU Xia,KONG Huating,ZHANG Jichao,ZHU Ying
        Vol. 45, Issue 8, Article number: 080502(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080502
        摘要：BackgroundSodium dodecyl sulfate (SDS) and polyethylene glycol octyl phenyl ether (Triton X-100) are commonly used for surfactants in the laboratory, which can dissolve lipids in the cell membrane, increase the permeability of cell membrane, and can assist the rapid penetration of staining reagents. Surfactants play an important role in immunostaining or tissue clearance.PurposeThis study aims to study the effect of SDS and Triton X-100 on cell membrane permeability.MethodsFirstly, the damage effects of SDS and Triton X-100 on cell membranes were compared and the optimal conditions were optimized. Then, the influence of the selection of SDS and Triton X-100 on the specific experimental results was investigated. Finally, the full-field transmission imaging technology of the soft X-ray nanoimaging beamline of the National Synchrotron Radiation Laboratory at Hefei was used to compare their affection on cell morphology before and after the cell rupture.ResultsExperimental results show that 0.25% Triton X-100 has better membrane penetration than 4% SDS, and the optimal treatment time of 0.25% Triton X-100 is 10 min. In the experiment of peroxidase catalyzed 3,3'-Diaminobenzidine (DAB) polymerization, SDS, rather than Triton X-100, affects the catalytic activity of enzymes, hence changes the staining effect. The synchrotron radiation high-resolution imaging demonstrate that there is no significant difference of cell morphology before and after the cell membrane permeability with Triton X-100.ConclusionsTriton X-100 is a better surfactant than SDS in the cell membrane permeability. The principal method of this study provides a good support for selecting suitable surfactants in the experiments.  
        关键词：Sodium lauryl sulfate;Polyethylene glycol octyl phenyl ether;Cell membrane permeability;X-ray imaging   
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      • “核素径迹贡献研究对反应堆物理和源项分析至关重要，专家采用线性子链方法，开发了核素径迹贡献统计计算模块，为核素转化途径分析提供新方案。”
        YANG Hongxin,ZHANG Jingyu,LI Pinglie,ZHAO Xiaoze,TAN Lin,XIAO Yixin
        Vol. 45, Issue 8, Article number: 080503(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080503
        摘要：BackgroundThe statistical study of nuclide track contribution is very important for reactor physics and source term analysis. It is helpful to understand the nuclide transformation paths and the contribution percentage of each path in practical engineering applications to identify important nuclides or nuclear reactions. The nuclide will be usually activated after the material is irradiated by neutrons.PurposeThis study aims to make statistics of nuclide track contribution which is closely related to activation calculation.MethodThe transmutation trajectory analysis method was employed to disassemble the complex reaction network into independent linear chains for analytical calculation, choose to retain the reaction chain while calculating the nuclide stock, and solve the statistical problem of nuclide pathway contribution in activation calculation. First, the transmutation trajectory analysis was searched by the backtracking method. Then, the pathway of the specified nuclide was tracked and the contribution percentage of each path producing the nuclide was obtained. Finally, the nuclide pathway contribution statistical calculation module was developed within the framework of self developed activation program ABURN, and a series of basic problems were tested and verified with comparison of the European activation program FISPACT.ResultThe comparison results show that the nuclide production paths calculated by ABURN are entirely consistent with that of FISPACT, so are the contribution percentage of each path.ConclusionsThe consistent results of ABURN and FISPACT verify that the accuracy of the track contribution statistical research method and program is ensured in this study, and the ABURN program has the functionalities of pathway tracking and contribution statistics.  
        关键词：Activation calculation;Transmutation trajectory analysis;Backtracking;Pathway contribution statistics   
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        发布时间：2024-10-25

        NUCLEAR ENERGY SCIENCE AND ENGINEERING

      • “在核反应堆辐射安全分析领域，专家发展了基于网格活化分析的精细活化分析方法，建立了MCFisMA程序，提升了活化源项及衰变γ剂量场计算精度，为反应堆屏蔽设计等提供理论与数据支撑。”
        LI Leiming,JIANG Shuyi,CHEN Zhenping,YUAN Xudong,YANG Chao,XIE Jinsen,YU Tao
        Vol. 45, Issue 8, Article number: 080601(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080601
        摘要：BackgroundNuclear reactor structural material activation analysis is an important part of nuclear reactor radiation safety analysis. The traditional cell-based activation analysis method can not describe the non-uniform spatial activation effect inside the structural material cells, resulting in a large deviation between the activation source and the dose results, so it is necessary to carry out the high-resolution activation analysis method for nuclear reactor structural materials.PurposeThis study aims to develop a high-resolution activation analysis method for nuclear reactor structural materials based on mesh activation analysis, and establish an integrated mesh-based activation analysis code (MCFisMA).MethodsFirst of all, based on Rigorous 2-step method (R2S), Monte Carlo particle transport program MCNP and activation calculation program FISPACT, the mesh-based activation method was used to divide the structural material model into fine spatial mesh, and the activation calculation of each mesh was carried out in turn to realize the precise activation calculation analysis of nuclear reactor structural materials. Then, the MCFisMA was implemented by using the neutron transport method, material activation method and activation-induced dose coupled together. In addition, NUREG/CR-6115 PWR model was used to study the application of high-resolution activation analysis of structural materials.Results & ConclusionsThe correctness and reliability of the proposed method and MCFisMA program is verified with the ITER shutdown dose rate (SDR) benchmark. The method presented in this paper has theoretical significance for improving the calculation accuracy of the activation source term and decay gamma dose field of nuclear reactor structural materials. It provides theoretical and data support for reactor shielding design, overhaul and refueling plan and decommissioning strategy.  
        关键词：Structure material;Rigorous 2-step method;Mesh-based activation;Nuclear reactor   
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      • “在空间深海探索领域，NUSTER堆芯热工力学性能研究取得进展，验证了堆芯设计安全性。”
        LIU Bo,LIU Limin,DING Guanqun,XIAO Yao,GU Hanyang
        Vol. 45, Issue 8, Article number: 080602(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080602
        摘要：BackgroundAs a nuclear power system with high energy density and strong adaptability, heat pipe cooled reactor can play an important role in space and deep sea exploration, and is attracting more and more attention from all over the world. Due to the solid-state core and high-temperature operation of the heat pipe cooled reactor, the thermal expansion and thermal stress are non-negligible. The nuclear-thermal-mechanical coupling effect should be considered for the heat pipe cooled reactor core.PurposeThis study aims to investigate the thermal-mechanical characteristics of the reactor core, and evaluate the safety performance of the reactor under typical conditions and transient accidents for a typical heat pipe cooled nuclear reactor, Nuclear Silence ThermoElectric Reactor (NUSTER).MethodsBased on FLUENT and MECHANICAL modules in finite element analysis software ANSYS, calculation of the nuclear-thermal-mechanical coupling was conducted for the reactor core of NUSTER under the steady-state and the reactor reactivity insertion accident respectively, hence the temperature and stress distribution were obtained. The core design safety was evaluated by comparing the temperature and stress peak values of each component with the melting point and yield strength of material.Results & ConclusionThe comparison results show that NUSTER core can operate safely within the safety limit in both steady state and accident conditions. Each component has a safety margin of 200 K for temperature and 150 MPa for stress under accident condition, so the core design safety has been verified.  
        关键词：Heat pipe cooled reactor;Nuclear-thermal coupling;Thermal-mechanical coupling;Core safety assessment   
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      • “在核反应堆严重事故缓解领域，专家开发了LHTCM模型，准确预测下封头蠕变行为，为防止放射性物质泄漏提供解决方案。”
        YANG Hao,ZHANG Bin,GAO Pengcheng,TANG Shaowei,SHAN Jianqiang
        Vol. 45, Issue 8, Article number: 080603(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080603
        摘要：BackgroundIn the event of a reactor severe accident, in-vessel retention (IVR) is a very effective and important severe accident mitigation measure. The lower head of the reactor pressure vessel (RPV) plays an important role in IVR strategy. The lower head is in a high-temperature environment, and its main failure form is creep failure. Once the lower head fails, it may lead to the release of radioactive substances into the environment.PurposeThis study aims to develop a thermal creep model for reactor pressure vessel lower head to ensure the successful implementation of IVR strategy and prevent radioactive material leakage, and apply this model to OECD lower head failure (OLHF) experiment analysis.MethodsThe thin shell theory and Norton-Bailey creep equation were employed to develop the lower head thermal creep module (LHTCM) model, and four failure criteria were used to evaluate the integrity of the lower head. Then, the LHTCM model was integrated into the integrated severe accident analysis program ISAA to verify and calculate the OLHF experimental data.ResultsThrough the analysis of four failure criteria in LHTCM model , it is found that the relative error between the failure time of the lower head predicted by the LHTCM model using the Larson Miller criterion and the experimental data is within 2.0%, and its predicted the elongation at the bottom of the lower head is more consistent with the experimental data than the other three criteria such as Kachanov criterion.ConclusionsLHTCM model developed in this study can accurately predict the creep behaviour of the lower head, and the calculated failure time, position and bottom elongation of the lower head are in good agreement with the experimental results.  
        关键词：In-vessel retention;Lower head;Creep failure;OLHF experiment   
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      • “在铅铋快堆安全运行领域，专家采用非参数统计法，基于CFD/PFS程序，对无保护超功率事故进行不确定性分析，为评估反应堆安全特性提供解决方案。”
        YU Qingyuan,QI Jingwen,ZHAO Pengcheng,ZHAO Yanan,YU Tao
        Vol. 45, Issue 8, Article number: 080604(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080604
        摘要：BackgroundTypical transient accidents pose a great challenge to the safe operation of lead-bismuth fast reactors.PurposeThis study aims to apply uncertainty analysis methods to transient calculations to reduce the "uncertainty band" of transient parameters and obtain more accurately assess reactor safety characteristics.MethodBased on the self-developed fast reactor analysis CFD/PFS code, non-parametric statistical methods was employed to carry out the uncertainty analysis of the unprotected overpower accident (UTOP) of small natural circulation lead-bismuth cooled fast reactor. Three types of uncertain input parameters, i.e., thermal-hydraulic model parameters, neutron physical model parameters, and fuel manufacturing tolerances, were considered according to the literature and engineering experience. Based on the uncertainty analysis procedure SIMLAB, the Latin hypercube sampling (LHS) was carried out for the input parameters, and the uncertainty of the transient safety parameters was quantitatively analyzed. Finally, the sensitivity of the input parameters to the transient safety parameters was evaluated by the correlation coefficient analysis method.Results & ConclusionComputational results show that uncertainty bands of target parameters, such as peak cladding temperature and peak fuel temperature, can all envelop the nominal value. The maximum tolerance of peak fuel temperature is 2 757.25 K, and the maximum tolerance of peak cladding temperature is 1 208.66 K. The analysis results indicate that the fuel average temperature and the reactivity feedback coefficient are the main sources of uncertainty.  
        关键词：Lead-bismuth cooled fast reactor;CFD/PFS;UTOP;Uncertainty analysis;Sensitivity analysis   
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      • “在核反应堆领域，专家通过CAMPSIS软件评估，揭示了堆芯功率变化对燃料包壳污垢沉积的影响规律。”
        LIAO Jiapeng,YE Jie,JIN Desheng,SHANG Chaohao,HU Yousen
        Vol. 45, Issue 8, Article number: 080605(2022) DOI: 10.11889/j.0253-3219.2022.hjs.45.080605
        摘要：BackgroundFor a pressurized water reactor (PWR), under the synthesis effects of primary water chemistry, reactor operation mode, system facilities replacement, fuel design and management, the corrosion products in primary coolant will deposit on the outer surface of fuel cladding, which is commonly called fuel crud. Fuel crud formed on the cladding surface may result in crud induced localized corrosion (CILC), crud induced power shift (CIPS) and raise the primary source term. The deposition behavior of fuel crud is affected by both the corrosion products concentration and the core boiling rate.PurposeThis study aims to investigate the influences of core power variation on the corrosion products concentration and the core boiling rate, and eventually evaluate the fuel crud deposition states under different core powers.MethodsThe core crud mass and the maximum crud thickness on fuel cladding surface were estimated by the CAMPSIS, an independent crud behavior analysis software developed by China Nuclear Power Technology Research Institute Co., Ltd (CNPRI). Influence of core power variation and the combined effect of core boiling rate and corrosion product concentration were analyzed.ResultsComputational results that, within the range of 75%⁓100% full power (FP), the lower the core power is, the smaller the core crud mass will be, but the maximum crud thickness will increase. When the core power decreases to 50% FP, the maximum boiling rate is close to zero, and both of the core crud mass and the maximum crud thickness are minimum.ConclusionsThe core power reduction of a nuclear reactor may lead to the increase of local fuel crud thickness, and adversely affect the heat transfer between the fuel cladding and the coolant. It is suggested that the influence of core power reduction on fuel crud deposition should be considered if a nuclear reactor tends to operate at a lower core power.  
        关键词：Pressurized water reactor;Fuel cladding;Core power;Crud deposition   
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