最新刊期
      卷 44 ， 期 7 ， 2021

        SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS

      • “上海软X射线自由电子激光用户装置提出全相干飞秒X射线脉冲产生原理，为相关领域研究提供新方向。”
        GAO Zhangfeng,YAN Jiawei,DENG Haixiao,LIU Bo,WANG Dong
        Vol. 44, Issue 7, Article number: 070101(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070101
        摘要：BackgroundX-ray free electron lasers (FEL), especially fully coherent femtosecond free-electron laser pulses, are widely used in numerous fields.PurposeThis study aims to propose a new principle for generating fully coherent femtosecond X-ray pulse based on the Shanghai soft X-ray Free Electron Laser User Facility (SXFEL-UF).MethodsThe principle was based on fresh-slice technique. First of all, the electron beam was kicked transversely to get a time-related transverse tilt. Then, the sub-10-femtosecond bunch was achieved because of the spatiotemporal synchronization effect of the seed laser modulation. The FEL pulse duration was even shorter because of harmonic lasing. In the cascaded high-gain harmonic generation (HGHG) mode, the laser generated by the beam tail modulated the beam head in the second stage to reach higher harmonics, while in the echo-enabled harmonic generation (EEHG) mode, the same part of the electron beam was modulated twice. The influence of emittance and energy chirp of the electron beam on the scheme was analyzed, and the instability caused by transverse position jitter and energy jitter of the chirped beam was evaluated.Results & ConclusionsIn the cascaded HGHG mode of SXFEL-UF, an X-ray pulse with peak power as high as 3 GW and pulse duration (FWHM) as short as 3.3 fs is obtained in the 3D simulation at 45th harmonic, and the relationship between the pulse duration and the transverse deflection of the beam is verified. The result of the 3D simulation for the EEHG mode is similar. The scheme is also explored to generate linearly polarized femtosecond pulse at 6 nm and circularly polarized femtosecond pulse at 3 nm simultaneously by means of the elliptically polarized undulator (EPU) afterburner.  
        关键词：X-ray;Femtosecond pulse;Energy chirp;Fresh-slice;Circular polarization   
        413
        |
        48
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588507 false
        发布时间：2024-10-25

        ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS

      • “在材料科学领域，研究者通过透射电子显微镜和纳米压痕仪，对比分析了选区激光熔化成形和传统工艺轧制的304L不锈钢在Xe离子辐照后的微观结构和硬度变化。研究发现，SLM 304L不锈钢的位错环和Xe泡数密度低于TM 304L不锈钢，但其Xe泡尺寸约为TM 304L不锈钢的3倍。辐照后，两种材料均出现硬化现象，其中SLM 304L不锈钢的辐照硬化程度低于TM 304L不锈钢。通过弥散强化模型计算，证实位错环和Xe泡是导致材料硬化的主要因素。”
        LI Ying,LI Jianjian,FU Chonglong,BAI Juju,HOU Juan,LIN Jun,DAI Zhimin
        Vol. 44, Issue 7, Article number: 070201(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070201
        摘要：BackgroundOwing to its excellent mechanical properties and corrosion resistance, 304L stainless steel is widely used as the core structure material in advanced nuclear power systems.PurposeThis study aims to investigate the damage characteristics of selective laser melted (SLM) 304L stainless steel under Xe ion irradiation and compare them with that of traditionally manufactured (TM) 304 stainless steel under the same experimental conditions.MethodsSLM 304L and TM 304L alloy samples were irradiated with 5 MeV Xe ions at 550 ℃. The irradiation dose was 3.53×1015 ions·cm-2. The microstructure and nano-hardness changes of the both alloy samples before and after irradiation were characterized by transmission electron microscopy (TEM) and nanoindentation, respectively. TEM samples were prepared by focused ion beam.ResultsThe TEM images show that dislocation loops and bubbles appeared in the irradiated alloy samples. The average sizes and number densities of dislocation loops in the SLM 304L and TM 304L alloy samples are (2.13±0.53) nm and (1.94±0.46) nm, 1.48×1022 m-3 and 6.94×1022 m-3, respectively. The average sizes and number densities of Xe bubbles in the SLM 304L and TM 304L alloy samples are (3.71±1.40) nm and (1.37±0.46) nm, 3.50×1022 m-3 and 1.73×1023 m-3, respectively. The both alloy samples show the irradiation hardening after Xe ion irradiation. The irradiation hardening degrees of the SLM 304L and TM 304L alloy samples are 14% and 32%, respectively.ConclusionsThe calculation results based on the dispersed barrier hardening model (DBH) reveal that the dislocation loops and Xe bubbles caused by irradiation play an important role in irradiation hardening of the two kinds of alloys.  
        关键词：SLM 304L stainless steel;Xe ion irradiation;Microstructure;Irradiation hardening   
        375
        |
        149
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588268 false
        发布时间：2024-10-25
      • “在2020年生态环境部辐射环境监测质量考核中，专家利用高纯锗γ谱仪，通过核素识别和定量测量，间接估算出气溶胶滤膜中总α和总β放射性活度，为气溶胶总放射性分析提供有益参考。”
        CHEN Cheng,LUO Maodan,WANG Liang,WANG Yulan,WANG Qian,XU Su,SHU Yijia,LI Guang
        Vol. 44, Issue 7, Article number: 070202(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070202
        摘要：BackgroundSichuan Radiation Environmental Management and Monitoring Center participated in the radiation environmental monitoring quality assessment organized by the Ministry of Ecology and Environment in 2020. Two total radioactivity standards prepared by Eckert & Zigler Analytics Corporation were used for test samples in this assessment.PurposeThis study aims to establish an indirect method for the estimation of total α or total β activities in the test samples based on HPGe spectrometer, and to provide some useful references for the application of this method in the analysis of aerosol total radioactivity.MethodsThe low background BE6530 HPGe spectrometer produced by Canberra (US) was used to identify nuclides of test samples and to collect their γ spectra data. Laboratory sourceless calibration software (LabSOCS) was used to calibrate the efficiency of the HPGe spectrometer. A γ-rays standard sample with multiple nuclides in an aerosol filter membrane and a self-made reference sample in an aerosol filter membrane were applied to confirm the reliability of the method established in this work.ResultsA formula is derived for the estimation of total α or total β activities by γ spectra data. The measurement results and uncertainties of total α and total β activities in the two test samples are 61.2 Bq and 73.2 Bq, 6.6% (k=2) and 3.6% (k=2), respectively. The results are all qualified after the Z-score evaluation. In addition, the parameter setting in LabSOCS, background deduction of γ spectra, γ peak selection and γ cascade radiation correction are discussed, which provides a useful reference for the application of this method in the total radioactivity analysis.ConclusionsThe indirect method established in this work has a good accuracy and can be applied in the analysis of aerosol total radioactivity.  
        关键词：HPGe spectrometer;Passive efficiency calibration;Nuclide analysis;Total α and total β test samples   
        402
        |
        47
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588531 false
        发布时间：2024-10-25

        NUCLEAR ELECTRONICS AND INSTRUMENTATION

      • “冷中子照相装置关键部件荧光屏研究取得新进展，新型荧光屏具有高分辨率、工艺简单及成本低等特点，为冷中子成像技术发展提供新思路。”
        LI Da,TAN Xizao,ZHANG Jilong,XUE Yunfei,LUO Wuxia,JIN Ke,YANG Lifang,WU Zhaohui
        Vol. 44, Issue 7, Article number: 070401(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070401
        摘要：BackgroundAs an excellent nondestructive testing technology, cold neutron radiography is widely employed to image materials of interest in many basic and application research fields. One of key components of such device is the neutron sensitive scintillation screen. Normally, these screens are made up of scintillation or phosphor powder mixed with/without neutron sensing isotopes, such as 6LiF:ZnS(Ag) and Gd2O2S:Tb. Uniform scintillation screens are very difficult to make a trade-off between spatial resolution and neutron detection efficiency. Recently a new type of micro-structural scintillation screens has been proposed, which is expected to have higher spatial resolution while maintaining higher neutron detection efficiency. Following this idea, a scintillation screen has been proposed, developed, and studied by our group.PurposeThis study aims to develop a new type of scintillation screens based on a glass capillary array filled with scintillation powders to achieve high spatial resolution and neutron detection efficiency.MethodsFirst of all, a neutron sensing scintillation screen was made by filling very fine grinded Gd2O2S:Tb phosphor powder into glass capillary arrays. Three main steps, i.e. the phosphor powder grinding, the particle size screening, and the vacuum suction filtration process, were taken making such screens. Then, photographs of Gd2O2S:Tb phosphor before and after grinding were taken with a scanning electron microscope (SEM) to examine the filling efficiency of scintillation powder in the glass capillary arrays. Finally, experimental test of spatial resolution of such scintillation screens was carried out by using an optical system to read out the scintillation light emitted by the screen, and a Siemens Star neutron test target to characterize the screens' spatial resolution with cold neutrons.ResultsX-ray luminescence spectra show that the grinding process reduces the light yield of the phosphor. The filling efficiency of scintillation powder in the glass capillary arrays is up to 70%. The cold neutron imaging system with developed scintillation screen achieves spatial resolution of about 300 μm@CTF=3% by experimental test.ConclusionsAlthough the new neutron sensing scintillation screen is still under-developing and there are still some problems to be overcome, cold neutron imaging scintillation screen based on glass capillary array filled with Gd2O2S:Tb phosphor, proposed in this study, can be used to achieve high spatial resolution and neutron detection efficiency with advantages of low cost and simple fabrication process.  
        关键词：Cold neutron radiography;Neutron scintillation screen;Glass capillary array   
        368
        |
        26
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588361 false
        发布时间：2024-10-25
      • “在强流重离子加速器装置注入引出Kicker电源系统中，研制了基于FPGA的通信系统，提高了数据通信效率和稳定性。”
        LIU Yan,GAO Daqing,ZHANG Huajian,LI Jiqiang,GAO Jie,SHANGGUAN Jingbin,LI Mingrui,JIN Xuejian
        Vol. 44, Issue 7, Article number: 070402(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070402
        摘要：BackgroundIn the injection and extraction Kicker power supply system of High Intensity Heavy-ion Accelerator Facility (HIAF), the transmission efficiency and stability of the control event directly affect the working performance of the power supply.PurposeThis study aims to develop the Kicker power supply communication system for precise control of hundreds of IGBT (insulated gate bipolar transistor) switches in the bipolar solid-state PFN-Marx generator of HIAF-Kicker power supply, hence to provide a gigabit readback path for the waveform data obtained by the high-speed acquisition system.MethodsBased on a digital controller with kernel Xilinx Kintex-7 FPGA (field programmable gate array) chip, the UDP (user datagram protocol) stack described by hardware language as the core of data communication was employed by the system. The scheme of intercepting waveform pulse and its front and back parts for transmission was adopted to improve the communication efficiency and save the system resources. The optical control signals required by the multi-channel power supply were provided by the controller via the connecting optical fiber daughter boards. The shielding case was added to reduce electromagnetic interference and enhance the stability of data transmission.ResultsThe data transmission test shows that the system meets the precise control demand of hundreds of IGBT switches, and the data transmit speed satisfies the needs of gigabit data readback.ConclusionsThe performance of designed system meets the communication requirements of Kicker power supply.  
        关键词：HIAF-Kicker;Communication;UDP hardware core;FPGA   
        400
        |
        29
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588111 false
        发布时间：2024-10-25
      • “在信号处理领域，专家基于拉式变换和Z变换分析C-R系统，提出了改进的离散解和C-R逆算子算法，实现了数字极零相消功能，为解决数字基线漂移问题提供解决方案。”
        JIN Youxian,ZHOU Jianbin,MA Yingjie,YUE Aizhong,HONG Xu,LIU Yi,WANG Min
        Vol. 44, Issue 7, Article number: 070403(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070403
        摘要：BackgroundIn nuclear radiation measurement, nuclear pulse signal can only process the analog circuit system in sequence, generally, signal distortion appeared.PurposeThis paper proposed inverse C-R algorithm aims at obtaining narrow nuclear pulse signal, implementing baseline elimination, and realizing better precision and high-resolution energy spectrum measurement under high counting rate.MethodThis paper makes detail study in C-R circuit system with Laplace transform and Z-transform, and corresponding continuous and discrete solutions to step signal and minus exponential signal of C-R circuit are presented, besides, considering the difficulty in algorithm deployment in FPGA (Field-Programmable Gate Array) with exponential parameter, Taylor expansion is applied to simplify the discrete response, which an modified discrete solution is also presented, besides, numerical solution of C-R system is also considered, the comparison of the three discrete solutions are simulated with MATLAB. And with suitable transform of C-R numerical solution, inverse C-R numerical solution is obtained, as appropriate choice of parameter, inverse C-R numerical solution can not only eliminate the undershoot in nuclear signal, but also realize the narrowing of the signal.Results & ConclusionsSimulation results presents that the three methods are in consistence in nuclear signal processing, and with suitable parameter setting, inverse C-R system can eliminate the undershoot and narrow the signal, and with accurate baseline estimation, baseline restoration can be realized with modified inverse C-R baseline eliminating algorithm.  
        关键词：Z transform;Inverse C-R transform;Time domain numerical analysis;Baseline restoration   
        368
        |
        26
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588063 false
        发布时间：2024-10-25

        NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH

      • “氟锆酸盐玻璃研究取得新进展，揭示了氟锆酸根离子结构演变过程，为提高光纤品质提供理论参考。”
        LAN Rongshan,LIU Yiyang,FU Xiaobin,LIU Hongtao,QIAN Yuan
        Vol. 44, Issue 7, Article number: 070501(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070501
        摘要：BackgroundFluorozirconate glass (ZBLAN) refers to the main matrix material of the mid infrared fluoride fiber. Based on the formation of the glassy network structure, the quality of glass fiber products can be determined.PurposeThis study aims to investigate the phase transition structure of ZrF4-based glasses.MethodsZrF4-FLiNaK was used as an experimental model system to replace the ZBLAN glass. In addition, the nuclear magnetic resonance (NMR) technique was employed to study the structure of ZrF4-FLiNaK glass model systems. An analysis was conducted on the chemical shifts of 19F, 23Na and 7Li spectra with different concentrations of ZrF4 by using the NMR technique. Moreover, in order to characterize the movement behavior of Li+ ion, the full width at half maximum (FWHM) of 7Li signal was analyzed.ResultsExperimental results show the coordination structure of Zr4+ in the system tendes to be evolved in the order of [ZrF7]3-, [Zr6F31]7- and [ZrF6]2- with the increase of the ZrF4 concentration. Furthermore, the Zr-F-Zr bridge bond in the network structure is formed, and the eutectic salt phase transforms into glassy state under the concentration of ZrF4 reaching 25.0 mol%. Besides, K+, Na+ and Li+ ions acts as modifiers and fills the glass state to improve the stability of the network structure.ConclusionsThe mentioned results indicate the formation of the glassy network structure and the effect of the alkali metal cation. On that basis, this study can provide a theoretical reference for investigating the glass structure containing ZrF4 and improving the quality of the optical fiber product.  
        关键词：ZrF4-FLiNaK glass model;Solid-state nuclear magnetic resonance;Glassy network structure   
        363
        |
        27
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588194 false
        发布时间：2024-10-25
      • “在核酸分析等领域，科学家通过精确调控DNA四面体尺寸，实现了对荧光染料各向异性的调控，有望开发新型优异探针。”
        HUANG Qiuling,CHEN Jing,LI Jiang,ZHU Ying,WANG Lihua
        Vol. 44, Issue 7, Article number: 070502(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070502
        摘要：BackgroundThe fluorescence anisotropy of intercalative dye plays important roles in nucleic acid analysis, the construction of fluorescent probes, and biosensing. However, there are few studies on the fluorescence anisotropy of intercalative dyes based on framework nucleic acids (FNA).PurposeThis study aims to use DNA tetrahedrons (TDN) as scaffold to build the fluorescence anisotropy probes of SYBR Green I, DAPI and DiYO-1.MethodsA series of TDN fluorescence anisotropy probes were constructed by precisely regulating the size of DNA tetrahedrons through DNA sequence design, characterizing DNA nanostructures by using synchrotron radiation small angle X-ray scattering (SAXS). The influence of TDN size on fluorescence anisotropy of SYBR Green I, DAPI and DiYO-1 was investigated by experiments.ResultsThe results show that the fluorescence anisotropy of probes increased with the increase of TDN size of SYBR Green I and DAPI, separately. For TDN/DiYO-1 probes, the fluorescence anisotropy decreases with the increase of TDN size as the edge length of TDN is between 7~20 bp, however, the fluorescence anisotropy increases as the edge length of TDN is bigger than 20 bp. After the dye interacted with the tetrahedron, the structure of DiYO-1 changes, resulting in the decrease of fluorescence anisotropy.ConclusionsTherefore, the fluorescence anisotropy of intercalators could be tuned by controlling the TDN size precisely. The fluorescence anisotropy probes based on FNA is expected to be an excellent probe.  
        关键词：Fluorescence anisotropy;DNA tetrahedron (TDN);Intercalators;Small angle X-ray scattering (SAXS)   
        368
        |
        28
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11587923 false
        发布时间：2024-10-25
      • “在中子成像领域，专家采用残差网络模型，实现了中子照相图像的无参考质量评价，为系统参数优化提供辅助手段。”
        QIAO Shuang,LI Junhui,ZHAO Chenyi,ZHANG Tian
        Vol. 44, Issue 7, Article number: 070503(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070503
        摘要：BackgroundThe quality of neutron radiographic images is mainly evaluated by human visual system (HVS), but HVS cannot be used as a real-time auxiliary for optimization parameters of neutron imaging systems.PurposeThis study aims to evaluate the quality of neutron radiographic images by no-reference image quality assessment (NR-IQA) and provide an effective approach for the parameters optimization of neutron imaging systems.MethodsFirstly, the plain natural images distorted with different distortion levels and types were labelled with quality scores to construct an experimental dataset by the gradient magnitude similarity deviation (GMSD) method. Then, the residual network (ResNet) model was employed to evaluate the quality of neutron radiographic images without reference images. Finally, the goal of extracting features and assessing the quality of neutron radiographic images was achieved by training the ResNet.ResultsThe model performs well in the test set of the experimental dataset and the quality prediction of the two group authentic neutron radiographic images.ConclusionsThe proposed quality assessment method could be used for the quality prediction of neutron radiographic images.  
        关键词：Neutron radiographic images;No-reference image quality assessment;Residual network;Gradient magnitude similarity deviation   
        382
        |
        23
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588163 false
        发布时间：2024-10-25
      • “在中子成像领域，新提出的自适应对比度增强算法通过粒子群优化算法自动寻优增强图像对比度，有效改善成像质量，具有推广应用价值。”
        CAO Xuning,CHEN Size,YU Jie,ZHANG Lianxin,ZHANG Zaodi,LI Taosheng
        Vol. 44, Issue 7, Article number: 070504(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070504
        摘要：BackgroundDue to the imaging mechanism of neutron radiography and the limitation of neutron source, neutron radiography images are prone to lack of contrast, and it is a common method to improve image quality by contrast enhancement algorithm.PurposeThis study aims to solve the problems related to low contrast and loss of details in neutron imaging.MethodsAn adaptive contrast enhancement (ACE) algorithm based on the particle swarm optimization (PSO) was proposed. First of all, the gain factor coefficient was treated as a particle and initializes a particle swarm. Then, the optimal gain factor coefficient with the PSO algorithm was calculated, and the contrast of the high frequency part of neutron images was improved through implementing this optimal gain factor coefficient in ACE algorithm. Finally, several neutron images were processed by this PSO algorithm and compared with the results of traditional optimization algorithm.ResultsThe new algorithm has obvious contrast enhancement effect for different neutron images, and the parameters such as entropy value, gray average gradient value and contrast value of the optimized image are improved compared with the traditional optimization algorithm.ConclusionsThis algorithm can enhance the contrast of image stably, which has practical significance for the wide application of neutron radiography.  
        关键词：Neutron radiography;Image enhancement algorithm;Adaptive contrast enhancement;Particle swarm optimization   
        391
        |
        24
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588308 false
        发布时间：2024-10-25

        NUCLEAR ENERGY SCIENCE AND ENGINEERING

      • “报道：小型熔盐堆堆芯设计，无需添料可运行1250天，放射性活度达7.36×10^18 Bq。”
        ZHOU Weilong,YAN Rui,ZHOU Bo
        Vol. 44, Issue 7, Article number: 070601(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070601
        摘要：BackgroundBased on the research of molten salt reactor (MSR), a conceptual design of small MSR core with thermal power of 100 MWt is proposed to meet the power supply demand of small area. By adjusting the initial fuel load of the reactor core, the reactor can operate at full power for 1 250 days without refueling, and then batch process fuel at the end of its life.PurposeThis study aims to analyze the yield and source of radionuclides in the main loop during such a small MSR operation by providing the constitutions, main components, and parameters according to the burnup characteristics and fuel salt characteristics of the long refueling cycle.MethodsThe calculation software KENOVI for three-dimensional Monte Carlo transportation program and burnup analysis module Origen-S were employed to analyze the fuel consumption analysis module, the storage of radioactive products in the main loop and the neutron energy spectrum and other neutron parameters.ResultsThe computation results show that the radioactivity at the end-of-life this small MSR is about 7.36×1018 Bq, and the radioactivity of fission products in the end-of-life primary loop is about 5.89×1018 Bq, of which the inert gases, iodine isotopes and the volatile fission metal account for 7.35×1017 Bq, 9.56×1017 Bq, 8.17×1017 Bq respectively. The total radioactivity of actinide nuclides is about 1.47×1018 Bq, of which the 239Np accounts for 98%.ConclusionsThis study provides reference for radiation protection design and fuel reprocessing scheme of molten salt reactor.  
        关键词：Molten salt reactor;Radioactivity;Primary loop;Actinoid nuclides   
        376
        |
        33
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11587966 false
        发布时间：2024-10-25
      • “在核反应堆抗震分析领域，专家采用ANSYS软件建立了三维有限元模型，计算了土壤-结构相互作用下的楼层反应谱，为TMSR-LF1地震安全评估奠定了基础。”
        LIU Yicheng,WANG Xiao,WANG Xiaoyan,FAN Huiqing,ZHANG Xiaochun
        Vol. 44, Issue 7, Article number: 070602(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070602
        摘要：BackgroundThe floor response spectra of the nuclear reactor building is of great significance to the seismic analysis and design of the whole reactor system.PurposeThis study aims to get accurate floor response spectra of 2MW thorium molten salt reactor-liquid fuel 1 (TMSR-LF1).MethodsA three-dimensional finite element model coupling with beam, shell and solid was established by ANSYS finite element analysis (FEA) software. The results of floor response spectra considering the soil-structure interaction (SSI) effect were obtained by direct method. Finally, comparison analyses of different floors, different inputs and different damping ratios were carried out.ResultsThe computation results show that the above-ground floor response spectra are much larger than that of the underground part, and the spectral values vary greatly due to the structure, load and other factors. The response spectra of each floor on the ground are larger in the vertical direction than in the horizontal direction.ConclusionsIn the seismic design of nuclear facilities, it is suggested to increase the vertical stiffness of the ground floor. The results of this study lay preliminary basis for seismic safety assessment of TMSR-LF1.  
        关键词：Floor response spectra;Soil-structure interaction;Nuclear reactor building;TMSR-LF1   
        401
        |
        31
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588037 false
        发布时间：2024-10-25
      • “在核电厂废油处理领域，专家通过超临界水氧化技术，实现了废油高效处理，为解决放射性废油处理难题奠定基础。”
        LI Shibin,XIA Xiaobin,QIN Qiang,WANG Shuai,MA Hongjun
        Vol. 44, Issue 7, Article number: 070603(2021) DOI: 10.11889/j.0253-3219.2021.hjs.44.070603
        摘要：BackgroundRadioactive waste oil mainly comes from the maintenance of equipment such as main pumps and steam turbines of nuclear power plants (NPP), and is a typical radioactive organic liquid waste (ROLW). Because there is no suitable treatment technology for ROLW, it can only be stored for a long time. Long-term storage has potential safety hazards such as leakage and fire.PurposeThis study aims to solve the problem of radioactive waste oil treatment by carrying out an experimental study on the supercritical water oxidation (SCWO) treatment of lubricating oil from NPP.MethodsA continuous SCWO reaction system was used as experimental platform with maximum working temperature of the 600 ℃ and pressure of 28.4 MPa. The effects of different reaction temperature, reaction time and excess oxygen coefficient on the chemical oxygen demand (COD) removal rate of VG 32 (Mobil DTE light turbine oil) lubricants were investigated. In addition, the reaction kinetics of SCWO treatment of lubricating oil from NPP at 420~580 ℃ was studied.ResultsThe experimental results show that the best operating conditions are reaction temperature of 550 ℃, reaction time of 80 s and oxygen enrichment coefficient of 250%. Under these conditions, the COD removal rate of organic matter is up to 96%. The activation energy Ea of the reaction is 43.10 kJ·mol-1, and the pre exponential factor A is 8.861 s-1. The deviation between the calculated value of the kinetic model and the experimental value is less than 3%.ConclusionsThis work proves the credibity of the model, and lays an experimental basis for supercritical water oxidation treatment of radioactive waste oil.  
        关键词：Supercritical water oxidation;VG 32 lubricant;COD removal rate;Reaction kinetics   
        369
        |
        22
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 11588428 false
        发布时间：2024-10-25
      0