核动力工程

Discrete Ordinates Method for Two-Dimensional Neutron Transport Equation Based on Unstructured-Meshes

JU Haitao, WU Hongchun, CAO Liangzhi, ZHOU Yongqiang, YAO Dong, XIAN Chunyu

2006, 27(3): 1-5.

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Abstract:
A discrete ordinates method for two-dimensional neutron transport equation based on un-benchmark problems demonstrate that this method can be used in unstructured-meshes and can give high pre-cision result.structured-meshes is derived from the first order neutron transport equation.A set of differential equations about the spatial variables can be obtained.They are solved iteratively by using the least-squares finite ele-ment method.A two-dimensional transport calculation code is encoded.The numerical results of some

Simplified Spherical Harmonics Method for Self-Adjoint Angular Flux Transport Equation in Unstructured Geometry

CAO Liang-zhi, WU Hong-chun, ZHOU Yong-qiang

2006, 27(3): 6-10.

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The simplified spherical harmonics (SP_N) method is utilized to discrete the angular variables of Self-Adjoint Angular Flux (SAAF) neutron transport equation as spherical harmonics method has the disadvantage of large amount of calculation. To solve the unstructured geometry problem, the spatial variables of SAAF are discretized by using of finite element method. Numerical results of several test problems show that SP_N method can obtain high accuracy with a significantly higher computational speed than spherical harmonics (P_N) method, and can save more time when dealing with problems with higher dimension, larger amount of meshes, and larger expanding order N.

Development of Transient Neutron Transport Calculation Code

WU Hong-chun, LIU Qi-wei, YAO Dong

2006, 27(3): 11-15,31.

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A transient neutron transport code for time-dependent analyses of neutronics systems, named DOT4-T, has been developed. The code is based on the Discrete Ordinates code DOT4.2, which solves the steady-state neutron transport equation in two dimensions. For the discretization of time variable, a direct method, the fully implicit and unconditionally stable time integration scheme, has been employed. The resulting code has been tested using several one-dimensional and two-dimensional benchmark problems, and the results obtained with DOT4-T shows very satisfactory agreement with the benchmark problem results.

MCCOOR Code System for Burnup Calculation

LI Jin-hong, ZHANG Song-bo, E.F.Kryuchkov, G.V.Tikhomirov

2006, 27(3): 16-19.

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A 3D Code system is developed for burn-up calculation by coupling the MCNP, COUPLE and ORIGEN-S. This work do some benchmark tests with the LWR(PWR and VVER) Pin-cell and Assembly mode. The VVER-100 fuel assembly (fueled with the UO₂ or MOX) with the burnable poison rod Gd benchmark results gave here. The k_inf and isotopic composition of the assembly are good agreement with the others Codes benchmarks. All the results verify the MCCOOR code system.

An Experimental Study on the Movement Mechanism of the High-Temperature Particles Falling into the Coolant Pool

HU Zhi-hua, YANG Yan-hua, ZHAN Jing-xiang

2006, 27(3): 20-23.

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Extremely high rapid evaporation could occur when high-temperature particles contact with low-temperature liquid. This kind of phenomenon is associated with the safety of engineering and the problems in high-transient multi-phase flow and heat transfer. In this paper, a special visualized experiment facility for small-scale interaction of high-temperature particles with coolant has been set up in the laboratory and the whole processes of the particles falling down have been recorded by a high-speed video camera. A series of experiments of a particle with different diameters and temperatures, falling into different sub-cooled liquids have been carried out, and the results have been analyzed and discussed. It is pointed out that the temperature and diameter of high-temperature particles and sub-cooled liquid are the important factors to affect the movement of particles.

Research on TACR Moderator Calandria by Porous Medium Method

LIAN Hai-bo, JIA Bao-shan, YANG Jue

2006, 27(3): 24-27.

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A porous medium method in unstructured grid is established in this paper, for numerical studies on fluid field and temperature field in calandria of Thorium based Advanced CANDU Reactor (TACR) moderator system. The results are proved to be correct compared with the precise numerical studies. The method in this paper is validated as an effective method to analyze TACR calandria.

Experimental Investigation on the Single-Phase Flow Friction in Narrow Annulus

LU Guang-yao, SUN Zhong-ning, WANG Jing, YAN Chang-qi

2006, 27(3): 28-31.

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Experiments are carried out to investigate the flow friction characteristics with/without heat exchange in narrow annulus. The experiments involve three flow directions, which are horizontal flow, upward flow and downward flow. The transition from laminar to turbulent flow in annulus is initiated earlier than that in normal circular tubes. The friction factors of narrow annulus are compared with the conventional correlations, and the influences of the temperature difference and the flow directions are analyzed.

Experimental Study on Kinematic Hardening of 1Cr18Ni9Ti Stainless Steel Under Low Cycle Fatigue

SHAO Er, YANG Xian-jie, MAO Jiang-hui, SUN Ya-fang

2006, 27(3): 32-36,52.

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To study the effect of the monotonic loading on subsequent cyclic plastic hardening and flow properties of 1Cr18Ni9Ti steel, an experimental study of the low cycle fatigue tests with mean strains for 1Cr18Ni9Ti stainless steel was carried out. An analysis on the evolutions of the yield surface radius and the back stresses under symmetric and asymmetric cyclic strain loading with different strain amplitudes was made .The dependence of the evolutions of the material kinematic hardening and isotropic hardening on the strain amplitude and mean strain was observed. These results provide the experimental foundation for the constitutive model of the material under combined monotonic and cyclic complicated loads.

LCF Behavior of Zr-4 Alloy at Elevated Temperature

YE Yu-ming, CAI Li-xun, LI Cong

2006, 27(3): 37-42.

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A series of strain fatigue tests were carried out on small bugle-like slice-specimens of Zr-4 alloy at room temperature and 400 . According to Elastic and Plastic Finite Element Analysis and assumption of local damage equivalence, a strain conversion equation was given to transform the transverse strain of the specimen to the axial strain. Based on the test results of the alloy and the strain conversion equation, fatigue life estimation equations of Zr-4alloy, or M-C (Manson-Coffin) models, were obtained. The results showed that, Zr-4 alloy had obvious cyclic hardening character during high amplitude strain at different temperatures, but showed reverse character during low amplitude strain. Elevated temperature lowered seriously the fatigue life of Zr-4 alloy, and as the increasing of amplitude strain, temperature effect impaired gradually. Analysis showed that the prediction life by using M-C model based on the traditional strain conversion equation was quite conservative when axial strain amplitude was less than 5000 micro-strain.

Measurement of Plating Thickness by X-ray Diffraction Method

LI Zhi-hai, ZHOU Shang-qi, REN Qin, SHI Quan, QIU Shao-yu, LI Cong

2006, 27(3): 43-46.

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Thickness of electroless Ni-P alloy plating has been measured by the substrate X-ray diffraction method and measurement error was analyzed. It shows that the method is one non-destructive method to measure the plating thickness with high precision, and its measurement error is less than that of metallographic method within its measurement range. This method can used to measure the crystal and noncrystal plating because it is hardly effected by the crystal state of plating.

Computation Method of Fuzzy Failure Probability of Nuclear Piping Containing Defects

ZHOU Jian-qiu, CHENG Ling

2006, 27(3): 47-52.

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Based on the theory of fuzzy probability, this paper addresses the randomness of assessment parameters and fuzziness of failure modes of nuclear piping, and points that the failure probability of nuclear piping is a fuzzy failure probability actually. A method to compute the fuzzy failure probability of pressure piping is proposed. Compared with the conventional reliability estimation method, which neglects the existence of fuzzy failure areas, the method proposed in this paper provides a more complete assessment and could lead to a more accurate prediction of piping reliability.

Estimation of the Human Error Probabilities in the Human Reliability Analysis

LIU Hai-bin, HE Xu-hong, SHEN Shi-fei, TONG Jie-juan

2006, 27(3): 53-56,66.

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Human error data is an important issue of human reliability analysis (HRA). Using of Bayesian parameter estimation, which can use multiple information, such as the historical data of NPP and expert judgment data to modify the human error data, could get the human error data reflecting the real situation of NPP more truly. This paper, using the numeric compute program developed by the authors, presents some typical examples to illustrate the process of the Bayesian parameter estimation in HRA and discusses the effect of different modification data on the Bayesian parameter estimation.

Application of RBF Artificial Neural Network to Fault Diagnose in Nuclear Power Plant

XIONG Jin-kui, XIE Chun-ling, SHI Xiao-cheng, ZHANG Hong-guo, SUN Tie-li

2006, 27(3): 57-60,96.

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Some faults of condensation and feed water system in nuclear power plants are analyzed and a fault knowledge base is established based on the experts’ knowledge at the same time. RBF artificial neural network is introduced to the fault diagnose in nuclear power plants. Because of the use of dynamic designing method of RBF network, not only the scale of RBF artificial neural network is smaller, but also its generalization ability is higher, which improve the speed and accuracy of diagnose system. Finally a fault diagnose system is founded by VC++.

Proof Test in Hot Condition on Steam Separation Device in Steam Generator for 1000MW PWR Nuclear Power Plant

CHEN Jun-liang, XUE Yun-kui, WANG Xian-yuan, CHENG Hui-ping, LIU Hong-yun, BA Zhang-xi, ZUO Chao-ping

2006, 27(3): 61-66.

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Steam-water proof test under nuclear power plant operation condition on the steam separation devices in steam generator for 1000MW PWR nuclear power plant has been conducted. The test result indicates that the steam humidity (carryover) in outlet of the steam separation device with optimized design features obtained by previous air-water screening test in cold condition is 0.0021% under nuclear power plant operation condition, which is less than the standard steam humidity (0.1%) required by the design of steam generator for 1000MW PWR nuclear power plant. Its performance under severe condition meets the design demand, and it is better than that of the advanced steam separation devices in other countries.

Data Communication of TXP/TXS System in Tianwan Nuclear Power Plant

ZHOU Hai-xiang

2006, 27(3): 67-70,82.

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The paper introduces the hardware and software design characteristics of Tianwan NPP TXP/TXS System data communication. Based on the analysis of the structure of data communication hardware and software, the paper points out that Tianwan NPP Digital I&C System data communication has the advantages of single failure toleration, high availability and validity, and it satisfies the high reliability requirement of NPP data communication.

Fuzzy Control of Pressurizer Dynamic Process

MING Zhe-dong, ZHAO Fu-yu

2006, 27(3): 71-74,86.

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Considering the characteristics of pressurizer dynamic process, the fuzzy control system that takes the advantages of both fuzzy controller and PID controller is designed for the dynamic process in pressurizer. The simulation results illustrate this type of composite control system is with better qualities than those of single fuzzy controller and single PID controller.

Design and Test of Flap Valve of Natural Circulation in CARR

LUO Zhi-yuan, LI Xiao-zhong, ZHOU Yuan, WANG Guang-jin, ZHANG Jian-wei, ZHOU Bin

2006, 27(3): 75-77,101.

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The flap valve of natural circulation was designed for the passive residual heat removal system of CARR (Chinese Advanced Research Reactor). Considering the functional requirements and performance parameters, the structure of two rotation assembly assemblies, i.e. the damping arm and a heavy weight part was adopted in the design to achieve the passive opening or closing motion of the flap valve. The function and the structure of the flap valve were described in this paper. The design calculation and the material selection and the performance test were also introduced. The performance test results showed that the flap valve can meet the design requirements.

Fatigue and Static Load Strength Analysis of Titanium Circularly-Grooved Cooling Tube

HUANG Wei-tang, YAN Chang-qi, ZHAOrigetu

2006, 27(3): 78-82.

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On the basis of mechanical parameters test, the fatigue strength analysis and static load strength analysis of the Titanium circularly-grooved tube were made. In addition, the numerical calculation of the stress concentrated parts was done by the finite element method. From the analysis and calculation, the conclusions were as follows: at the condition of the condenser was normally operating, the Titanium circularly-grooved tube could fulfill the requirements of the fatigue strength and static load strength; The thermal stress was relatively large in the resulted stresses from various loads. For a condenser more safe, it is necessary to equip the expanding node at the end of condenser shell to decrease the thermal stress; Titanium circularly-grooved tube applied in the condenser was safe only if the groove was designed properly and the shaping technique of the circular groove was very well.

Program for Real-Time Simulation of Reactivity Feedback

WU Xiao-hang, ZHAO Hua, ZHENG Jin-wen, JIANG Xu-lun

2006, 27(3): 83-86.

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The code to simulate reactivity feedback during out-of-pile testing has been developed with C++ in the paper. Simulation of reactivity feedback, simulation of the system of power control and simulation of neutron kinetics are the main modules of the code. There are three main physical models, i.e., point-reactor model for neutron dynamic, one-dimensional homogenous flow model for hydrodynamic and onedimensional transient heat conduction model for fuel dynamic in the code. The scheme of simulation of power control system is established with a conservative average reactor temperature. The auxiliary calculation modules such as calculation of physical property parameter and calculation of geometric parameter are also taken into account. Finally, the data given by Retran-02 are selected to validate the present code and the results indicate that our code meets the requirement of real-time simulation of reactivity feedback.

High Temperature Gas-Cooled Reactor Simulation System Based on Isomerous Network

LI Si-feng, MA Yuan-le, SHI Lei, LI Fu

2006, 27(3): 87-91.

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A high temperature gas-cooled reactor simulation system based on isomerous network is presented in this paper, where C/S structure is adopted. The computing server has been developed with the help of mixed programming of Fortran 77 and C language under Redhat Linux 7.3 Operating System, while the Client has been designed by using Delphi 6.0 under Windows XP Operating System. The simulation results are coincident with the experimental ones, which shows that it is feasible to design the high temperature gas-cooled reactor simulation system in the isomerous network frame with Linux and Windows operating system coexisting.

Modeling and Simulating of Power Regulating System of a Research Reactor

FENG Jun-ting, HUANG Xiao-jin, ZHANG Liang-ju

2006, 27(3): 92-96.

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As a new type of research reactor, no experience can be used for the design and implementation of the power regulating system. So it is necessary to determine the algorithm, parameters and its dynamic characteristics through modeling and simulating for reactor power regulating system. Modeling and simulating system is a simulated close-loop control system. The power regulating system implements arithmetic of power regulating on the basis of difference between current and given power, then outputs stepping motor controlling signal in order to regulate power. Different control methods with close-loop control system were experimented on the modeling and simulating system. The results indicate that the given control target and control performance are fulfilled preferably by different rod position adopting different controller parameters. The study and its results would provide theoretical and methodological basis for the design and implementation of the power regulating system of the new type nuclear reactor.

Development of Supplier Evaluation Model Applying in Nuclear Power Plants

WANG Yong-gang, FANG Chun-fa

2006, 27(3): 97-101.

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It is essential for the safe and stable operations of Nuclear Power Plants that various resources in the supply chain are effectively managed. Supplier is a significant resource of nuclear entities serving as an extension of the operation process. Scientific and rational evaluation of the performance of suppliers is of vital importance to an effective and high quality supply chain. This paper establishes an advance and practical supplier evaluation system that is applicable for the operational nuclear power plants, based on the analysis of the current operation status of Daya Bay Nuclear Power Station against its targeted objectives, the acquisition of relevant practices home and abroad and the benchmarking with advanced peers, in order to enhance the core competence of nuclear power plant.

Numerical Analysis of Steam Reformer of Steam Methane Reforming Hydrogen Production System Connected with High Temperature Gas Cooled Reactor

YIN Hua-qiang, JIANG Sheng-yao, ZHANG You-jie

2006, 27(3): 102-107,112.

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In order to quantitatively analyze the performance of the helium-heated reformer used in steam methane reforming hydrogen production system connected with high temperature gas cooled reactor, a dynamic model has been set up based on one-dimension quasi-homogeneous phase model. And a computer program is developed. Model verification is performed under steady state using test results of Japan Atomic Energy Institute. The steady state calculation results fit well with the experiment results. Reaction velocity is not the main factor influencing the performance. Reformer tube with finned central tube improves the performance remarkably comparing with smooth central tube.

Study on Sorption Capacity of Synthetic Zeolite for Simulated Nuclide Cs⁺

WANG Jin-ming, YI Fa-cheng

2006, 27(3): 108-112.

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For the sake of understanding the functionary order of simulated nuclide Cs⁺ and Synthetic Zeolite(ZF), the sorption equilibrium time and sorption capacity of simulated nuclide Cs⁺ on ZF are studied with the intermittence method. The difference of temperature pH value, Cs⁺ concentration and medium on sorption capacity and sorption ratio are investigated. The results show that the sorption complexion of simulated nuclide Cs⁺ on ZF in the same concentration solution are sorption equilibrium quantity in range of 155~190 mg/g in different temperatures and that in range of 165~190mg/g in different pH values and that in range of 120~210mg/g in different media; and changing order of equilibrium adsorption ratio is the same to that of sorption equilibrium quantity, but their changing range are wider than that of sorption equilibrium quantity; equilibrium adsorption quantity in range of 180~380mg/g in different concentration solutions, and changing order of equilibrium adsorption ratio is opposite to that of sorption equilibrium quantity, and moreover, their changing range are wider than that of the sorption equilibrium quantity. Sorption equilibrium time of simulated nuclide Cs⁺ on ZF is about ten to fifteen days. So the changing range of sorption capacity of simulated nuclide Cs⁺ on ZF with conditions effects is smaller and the sorption equilibrium time is also less and ZF preferably absorbs Cs in radiation wastes and thus consumedly reduces the effect of radwaste on the environment.

2006 Vol. 27, No. 3