最新刊期
      卷 40 ， 期 9 ， 2017

        NUCLEAR ELECTRONICS AND INSTRUMENTATION

      • Li CHEN,Min GU,Guoqiang ZENG,Liangquan GE,Kun YANG,Ming XIAO
        Vol. 40, Issue 9, Article number: 090402(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090402
        摘要：Background: The proportion subtraction method used in radon daughters subtraction algorithm for continuous artificial radioactive aerosol monitor has disadvantages such as rough classfication, less accuracy and low adaptability. Purpose: This study aims to improve the accuracy of subtraction to reduce the detection limit. Methods: A novel algorithm is proposed by classifying the spectral lines through clustering analysis and then calculating each clustering using neural network. Experimental verifcation is performed to compare this method with the proportion subtraction method. Results: The results showed that the cluster analysis and neural network subtraction algorithm can reduce more than 20% of the detection limit for the continuous artificial radioactive aerosol monitor. Conclusion: The algorithm proposed in this paper is effective for subtracting radon daughters.  
        关键词：Aerosol;Radon daughters;Clustering analysis;Neural network   
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        发布时间：2021-05-19
      • Jicheng LI,Congzhan LIU,Yifei ZHANG,Jianling ZHAO,Bo YAN
        Vol. 40, Issue 9, Article number: 090401(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090401
        摘要：BackgroundThe hard X-ray modulation telescope (HXMT) is devoted to performing an X-ray all-sky imaging survey, and carrying out pointed observations of the celestial bodies such as black-hole with high sensitivity. The 18 high energy X-ray detectors (HEDs) are the main payload on the HXMT. PurposeThis study aims to design a new type of multi-channel pulse wave analyzer for hard X-ray for the HEDs. MethodsBased on field programmable gate array (FPGA) technology, the pulse wave analyzer is structured with two FPGAs, eight high speed acquisition analog-to-digital converters (ADCs) (with 96-MHz clock driver), 32 K×16 dual port random-access memory (RAM) and one universal serial bus (USB) 2.0. It can deal with 8-channel input pulses in parallel to obtain pulse height, width and reaching time from each channel. All those data can be displayed in real time on computer. ResultsIt is confirmed experimentally that the pulse wave analyzer performance is comparable with the MCA8000D in energy spectral acquisition. ConclusionThis pulse wave analyzer has been successfully used in the HEDs performance testing, and can be used widely in the radiation detection.  
        关键词：FPGA;Multiple channel;High resolution;Pules wave analyzer   
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        发布时间：2021-05-19

        NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH

      • Jiawei LU,Wei SU,Hua XIE
        Vol. 40, Issue 9, Article number: 090501(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090501
        摘要：Background: The cement medium is usually used to solidify the uranium-bearing wastewater, however, little attention was paid to adsorption capacity and mechanism of the cement powder in related search reports. Purpose: This study aims at the static adsorption behavior of geological special cement blank powder for uranium-bearing wastewater. Results: The results show that the adsorption equilibrium of static adsorption of geological special cement for uranium solution at different concentrations (20 mg·L-1, 30 mg·L-1 and 40 mg·L-1) was at 1.5 d. The maximal adsorption capacity (qe) was 40.257 mg·g-1, 60.423 mg·g-1 and 80.386 mg·g-1, respectively, and the final static equilibrium adsorption rate was up to 99.95% when the concentration of uranium solution was kept at 30 mg·L-1, the adsorption rate of geological special cement for U(Ⅵ) could reach 99.50% no matter the pH value of adsorption system changes among 5, 7 and 9. Conclusion: The geological special cement has a strong adsorption capacity for U(Ⅵ), and its adsorption effect is basically not affected by the concentration of uranium solution and the pH value. The pseudo secondary dynamical model can describe the whole adsorption process (t=0-41 d) well, and its correlation coefficient R2 is up to 99.99%, which demonstrates that the adsorption rate evolves according to the positive correlation relation with the square of the adsorption driving force (qe-qt).  
        关键词：Uranium-bearing wastewater;Geological special cement;Static adsorption;Dynamic model   
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        发布时间：2021-05-19
      • Yunhua QING,Pan LIU,Qishan ZHENG,Yan ZHANG,Lihua HUANG
        Vol. 40, Issue 9, Article number: 090502(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090502
        摘要：Background: Currently, mixture calibration sources, generally used in laboratory for saving cost, are limited in spectrum analysis.Purpose: The aim is to study the suitability of two spectrum analysis methods under the condition of mixture calibration source. Methods: In this work, four radionuclides, 241Am, 60Co, 137Cs, and 40K, were measured by HPGe γ spectrometry and analyzed with relative comparison and efficiency curve methods under the condition of the mixture calibration source. Results: Relative comparison method can not calculate the radioactive activity of test nuclide influenced by interference nuclide, if interference nuclide could be ignored in mixture calibration source. Conclusion: Relative comparison method has an advantage comparing with efficiency curve method, if interference nuclide has no effect on test nuclide included in sample, but has a great effect on test nuclide included in mixture calibration source. However, efficiency curve method has an advantage comparing with relative comparison method. If interference nuclide has a great effect on test nuclide included in sample, but no effect appears on test nuclide included in mixture calibration source.  
        关键词：HPGe γ spectrometry;Mixture calibration source;Analytical methods;Radionuclides   
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        发布时间：2021-05-19

        NUCLEAR ENERGY SCIENCE AND ENGINEERING

      • Quansheng FENG,Bo XU,Deng PAN,Yang ZOU,Hongjie XU
        Vol. 40, Issue 9, Article number: 090601(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090601
        摘要：Background: The flow field design at the core inlet has a particularly important influence on structure stability, temperature distribution and flow field of a small solid fuel salt reactor system.Purpose: This study aims to optimize the flow channel structure by analyzing the effect of the thermal-hydraulic characteristics.Methods: Base on the design of a small molten salt pebble-bed reactor, input parameters of the practical boundary conditions were adopted for simulation study using Fluent 16.0 of computational fluid dynamics (CFD).Thermal-hydraulic characteristics such as temperature field, flow field and pressure drop, of core inlet were simulated through changing the flow areas.Results: The computational results showed that when proportion of the flow area was in the range of[0, 15.00%], the maximum local temperature in the active core region increased and the pressure drop in the core inlet decreased with the increase of the flow area.As the channel is far away from the core position, salt velocity increases gradually along the radial direction.Conclusion: The numerical results provide a useful proposal to optimize the design of a small solid fuel salt reactor.  
        关键词：Solid state molten salt reactor;Inlet flow distribution;Molten salt channel;Thermal-hydraulics   
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        发布时间：2021-05-19
      • Jinghua WANG,Maosong CHENG,Zhimin DAI
        Vol. 40, Issue 9, Article number: 090602(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090602
        摘要：Background: Thorium-based molten salt reactor (TMSR) nuclear energy system is one of the first batch strategic pilot science and technology projects launched by Chinese Academy of Sciences. It aims to develop nuclear energy system of the fourth-generation reactor. The solid fuel thorium-based molten salt experimental reactor (TMSR-SF1) with thermal power of 10 MW is a fluoride-salt-cooling pebble bed reactor, has its preliminary project and engineering design completed. Reactor power control system is a key part of nuclear reactor, which can realize the normal start-up, power operation and normal shutdown of the reactor, and thus plays an extremely important role in ensuring the safety and stable operation of the reactor. Purpose: This study aims to design a self-adaptive power control system for TMSR-SF1. Methods: Firstly, the adaptive law of adaptive controller is designed based on Lyapunov stability theory. And then, the adaptive model is established in Simulink and numerical research is carried out on the TMSR simulation platform. Finally, the characteristics of the controller are analyzed based on the numerical results. Results: The numerical results show that the adaptive parameter γ is very important to adaptive law, and control system could achieve better tracking performance only when γ is appropriate. When there is unmeasurable disturbances, control system can quickly absorb them and keep working in better condition. Conclusion: The model reference adaptive power controller is stable and reliable, and has strong anti-interference ability, which can satisfy the control requirements of TMSR-SF1's core power following load.  
        关键词：Solid fuel molten salt reactor;Adaptive controller;MATLAB/Simulink;Power control;Simulation   
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        发布时间：2021-05-19
      • Jing ZHAO,Kai WANG,Xiaowei JIAO,Zhaozhong HE,Kun CHEN
        Vol. 40, Issue 9, Article number: 090603(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090603
        摘要：Background: Reactor vessel auxiliary cooling system (RVACS) is a passive residual heat removal system applied to thorium molten salt reactor-solid fuel (TMSR-SF1). There are difficulties to use it to high-power reactor with its multifunction reactor vessel. To maximize vessel integrity, vessel should be minimized. Purpose: This study aims to verify the heat-discharge capability of the RVACS under station blackout accident (SBO). Methods: With a 10-MW fluoride salt-cooled high-temperature reactor (FHR) designed by Shanghai Institute of Applied Physics of Chinese Academy of Sciences as the baseline design, the RELAP5-MS code was adopted to simulate the transients during a SBO. Results: A scope of RVACS power for heat dissipation of FHR under SBO is given by this study. Conclusion: The heat-discharge capability of the RVACS was verified.  
        关键词：FHR;RVACS;RELAP5-MS;Station blackout   
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        发布时间：2021-05-19
      • Ming DAI,Guifeng ZHU,Ye DAI,Yang ZOU,Xiaohan YU
        Vol. 40, Issue 9, Article number: 090604(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090604
        摘要：Background: The control rods of pebble-bed fluoride-salt-cooled high-temperature reactor (PB-FHR) are located in the side reflector. Neutron diffusion calculation in those control rods has difficulties of no fission source in the control rod region and strong effect from the core leakage spectrum. Purpose: This study aims to apply super homogenization (SPH) method in diffusion calculation for PB-FHR. Methods: SPH method is applied in the diffusion calculation for the strong absorber in control rod region located in the reflector area of the PB-FHR, through which the local area of control region is homogenized. The spectra of different places of the reactor core except the control rod region are calculated to modify its cross sections. SPH factors calculation is accomplished by an iteration procedure between SPH and spectra modification (SM). Results: Reactivity worth of the control rod and neutron flux distribution are calculated accurately. Conclusion: Compared with the fine mesh transport reference solution, the verification results demonstrates that the method proposed can accurately model the control rod including the reactivity worth and flux distribution, and it is more suitable for the situation with interference effect between different control rods compared with regular SPH method.  
        关键词：PB-FHR;Control rod;SPH;Strong absorber   
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        发布时间：2021-05-19

        NUCLEAR CHEMISTRY, RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE

      • Huan QIN,Xinxin WANG,Kun TIAN,Bing XIA
        Vol. 40, Issue 9, Article number: 090302(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090302
        摘要：BackgroundIt is difficult to measure 226Ra in water accurately because of its low content. The existing three methods have the disadvantages such as complex sample processing, large measurement error and lower detection limit, and thus could not satisfy the measurement needs. PurposeThis study aims to build a new gamma-spectrometry method to analyze 226Ra in water simply and accurately with reasonable lower limit. MethodsFerric hydroxide calcium carbonate was used as carrier for226Ra in water. ResultsExperimental results shows that the spiked sample recovery rate by this method is higher than 83.0%, the average recovery of each group is higher than 90.9%, the accuracy range is 2.05%-12.7%, and the precision range is 3.20%-5.38%. The relationship between the detection limit and the usage of the sample is calculated using the sourceless efficiency calibration software. The best sample sizes are 40-60 L, and at this point the lower detection limit is about 2.0 mBq·L-1. ConclusionThe results show that the method is accurate and reliable, which can be used to analyze and determine the content of 226Ra in water.  
        关键词：Gamma-spectrometry analysis;Method recovery;Lower detection limit;Accuracy;Precision   
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        发布时间：2021-05-19
      • Zhanyuan LIU,Hu ZHANG,Riteng WANG,Yongzhi NING
        Vol. 40, Issue 9, Article number: 090301(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090301
        摘要：BackgroundExtraction and separation of neptunium is one of the focused research topics in the field of reprocessing. As an organic salting-free reductant, because of its reduction rate differences between Np(Ⅵ) and Pu(Ⅳ), methyl hydrazine (MMH) has the potential to separate Np/Pu. PurposeIn this study, the feasibility of applying MMH to reductive stripping separate Np/Pu was evaluated. MethodsThe reductive back-extraction dynamics of Np(Ⅵ) and Pu(Ⅳ) by MMH were investigated using a single-stage extraction device. ResultsBy investigating the effects of the concentration for nitric acid and methyl hydrazine nitrate, as well as reaction temperature on the reductive stripping process, the Np(Ⅵ) and Pu(Ⅳ) stripping kinetics equation and their apparent activation energy were determined. ConclusionFurther, the half reaction time of reductive stripping Np(Ⅵ) and Pu(Ⅳ) with hydrazine nitrate can be obtained by means of kinetics equation, and a preliminary exploration for Np(Ⅵ)/Pu(Ⅳ) separation was carried out.  
        关键词：Methyl hydrazine;Reduction stripping;Neptunium;Plutonium   
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        发布时间：2021-05-19

        LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS

      • Yufu DENG,Shan GU,Yawei XIANG,Hairong PANG,Dechuan MENG,Qingchao PAN,Wei HUA,Guiying YU
        Vol. 40, Issue 9, Article number: 090201(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090201
        摘要：BackgroundMagnesite is the main raw material for manufacturing magnesium products, so it is important to determine accurately the magnesium content in magnesite during the mining and refining of magnesite resources. PurposeThis study aims to develop a method to determinate the magnesium content in magnesite by energy dispersive X-ray fluorescence (EDXRF) analysis. MethodsWith the chemical pretreatments of the magnesite sample, the relationship between the target element magnesium and the medium atomic number element barium was established. This enabled us to determine the magnesium content in magnesite by the measurements of barium content using EDXRF. ResultsThe measuring accuracy of magnesium content in magnesite was 29.43% with the relative standard deviation of 0.58%. ConclusionThe results show a good precision and reproducibility of the measurements, which suggests that this method is an ideal choice for the light element Mg determination instead of direct measurements by EDXRF analysis.  
        关键词：EDXRF;Magnesite;Magnesium   
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        发布时间：2021-05-19

        SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS

      • Chuanqian PENG,Yumei HE,Jie WANG
        Vol. 40, Issue 9, Article number: 090101(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090101
        摘要：Background High accuracy profile metrology systems are important instruments for the metrology of X-ray mirrors used in many areas like synchrotron facilities and telescopes. Many systematic errors introduced by manufacture defects of optical elements of these metrology systems will affect its performance. Purpose This study aims to design a novel high-accuracy deflectometric profiler system to meet the state-of-art high-accuracy metrology requirement of 3rd generation X-ray light sources and X-ray free electron lasers. MethodsA new type of deflectometric profiler system, based on normal tracing principle, was proposed in which a pinhole and a light source are used to make a beam select system to automatically select a beam which propagates along the normal direction of the measured area on the surface under test. The profile information of the surface under test could be measured by measuring the angle variation of the selected beam. ResultsSystematic errors introduced by manufacture defects of optical elements could be minimized by placing these optical elements as close as possible to the pinhole. ConclusionBy using the normal tracing principle method, high accuracy metrology for strong curved mirror is possible.  
        关键词：Normal tracing principle;Manufacture defects;Inhomogeneity;Deflectometric profiler system;Synchrotron facility   
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        发布时间：2021-05-19
      • Yaolin PAN,Chengwen MAO,Deming SHU,Aiguo LI
        Vol. 40, Issue 9, Article number: 090102(2017) DOI: 10.11889/j.0253-3219.2017.hjs.40.090102
        摘要：BackgroundThe spatial resolution and focusing efficiency are the key parameters for X-ray micro-and nano-probe. Aspherical bent mirror is of great advantages such as high spatial resolution, high focusing efficiency, easy machining and achromatic. PurposeThis study aims to design a sub-micron focused bending mechanism. MethodsA high-precision flexure bending mechanism is designed for hard X-ray micro-focusing beamline (BL15U1) at Shanghai synchrotron radiation facility (SSRF) on the basis of exact bending theory. The simulation of finite element analysis (FEA) and width optimization are completed. Finally proposed bending mechanism was tested by long trace profiler (LTP). ResultsThe testing results show that the achieved slope error is 430 nrad. ConclusionThis high-stability flexure bending mechanism can produce a theoretical spatial resolution at 230 nm.  
        关键词：X-ray micro-and nano-probe;Aspheric bent-mirror;Flexure hinge;Finite element analysis   
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        发布时间：2021-05-19
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