核动力工程

Coupling of Neutronics and Thermal-Hydraulic of CANDU Fuel Management Program and Modification of Time-averaged Model

HUO Xiao-dong, XIE Zhong-sheng

2004, 25(6): 481-484,504.

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In this paper, a nonlinear iteration semi-analytic nodal method to solve the diffusion equation and a steady-state single channel thermal-hydraulic code are developed and integrated in the package FMPHWR to realize the coupling of neutronics and thermal-hydraulic. Based on the experiences from PWR, a similar cross-section parameterized method to be used in CANDU is proposed to consider the feedbacks of local parameters. A modified time-averaged model is proposed on the basis of the traditional one. The numerical results show that FMPHWR has superior computational accuracy.

Nondestructive Determination of Fuel Burn-up in Xian Pulse Reactor

A Jing-ye, CHEN Da, ZHANG Wen-shou, CHEN Wei, JIANG Xin-biao, WANG Kai, CHANG Yong-fu

2004, 25(6): 485-488,521.

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A method for the nondestructive determination of fuel burn-up in Xian Pulse Reactor （XAPR） by gamma-ray spectroscopy is introduced. This method utilizes the activation data of fission product ¹³⁷Cs, . irradiation history, correction calculation and theory analysis to calculate the burn-up. Some other key technologies are also discussed in the paper.

Contrast Analysis of Thermal-Hydraulic Qualities of Helical Tube Steam Generator between One and Two Dimensional Models

YÜ Yü, JU Huai-ming, MA Chang-wen

2004, 25(6): 489-493,516.

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Based on the study of theoretical and experimental research on thermal-hydraulic qualities of fluid in helical tube steam generator in the world, two-dimensional model is proposed for generator used in high-temperature gas cooling reactor （HTR-10） in this paper, and the results are compared with experiment results and results from one-dimensional model. The equations in one-dimensional model are simple, and calculation is convenient, yet the empirical formula for helical tube, especially for small banding radius helical tube are not sufficient, and so modification based on the experiments is necessary. Fluid field can be simulated better on two-dimensional model, and the empirical formula for straight tube can be used directly, the calculation error are within 10%, and the effect of power and inlet throttle for system stable can be described by the results of dynamic program.

Investigation on the Heat Transfer Characteristics of the Steam-Water Two-Phase Flow in the Inclined Upward Smooth Tube in Sub-Critical and Near Critical Pressure Regions

YIN Fei, CHEN Ting-kuan, LI Hui-xiong, LUO Yu-shan, HU Zhi-hong, TANG Ren-hu

2004, 25(6): 494-498,513.

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Under sub-critical and near critical pressures, the heat transfer characteristics of the steam-water two-phase flow in the inclined upward smooth tube with the diameter of φ 32×3mm and the inclined angle of α ＝ 20 were investigated experimentally. The tests were performed at p＝ 13～ 21.5MPa, G ＝ 600～ 1200kg/(m²· s) and q＝ 200～ 600kW/m²。The results show that the wall temperatures and the internal wall heat fluxes non-uniformly distribute along the circumference of the inclined upward tube, and that the non-uniform distribution can be decreased and even eliminated by increasing the mass velocity. At different working conditions, the influence laws of the pressures on the heat transfer are different. The correlation of the minimum heat transfer coefficient of the inclined tube has been provided and can be used as a reference in the design of engineering practices.

Method to Reduce Void Fraction in the Neutron Moderator Cell of CARR CNS

WAN Lian-li, CHEN Ting-kuan, BI Qin-cheng, WANG Hai-jun, FENG Quan-ke

2004, 25(6): 499-504.

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The moderator cell is of great importance in CNS system, which is a main part of Chinese Advanced Research Reactor （CARR）. Void fraction in the moderator cell has great influence on the moderation ability, safety of reactor and so on. In order to decrease the void fraction in the annular channel between the moderator cell and the inner cell, holes may be opened in the top of the inner cell, so that some hydrogen gas vaporized from liquid hydrogen under the inner cell can be discharged without flowing through the annular channel. After a series of measurement of the relation between pressure drop and mass flux in small diameter short pipes, a correlation was obtainded, according to which the optimized number and diameter of holes are calculated. Moreover, self-adjusting ability and stability of this method at variable reactor powers is analyzed.

Time Dependent Failure Assessment Curves of 10CrMo910 and 316 Stainless Steel

XUAN Fu-zhen, TU Shan-dong, WANG Zheng-dong, MA Chun-wei

2004, 25(6): 505-508.

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Tensile creep tests on 10CrMo910 heat resisting steel and 316 stainless steel were carried out for 10000 hours. On the basis of the experimental results, the isochronous stress-strain curves and time- dependent failure assessment curves （TDFAC） of these two steels were given. Finally, the corresponding formulae for long-term creep state, which could be utilized in the high temperature defects assessment, were established.

Information Quantity Simulation on Life Distribution

LI Chao, ZHAO Yong-xiang, WANG Jin-nuo

2004, 25(6): 509-513.

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The comprehensive evaluation mode of life distribution is prensented under limited data. The mode of the life distribution takes into account the total fit, the consistency with fatigue physics and the safety of the tail regions. The total fit is assessed by correlation coefficient. The consistency with fatigue physics is analyzed by the hazard rate curve of distribution. The safety of design is predicted by examining the change of predicted errors in the tail regions of distribution. The quantitative comprehensive evaluation mode is con-structed based on information theory when life statistical distribution satisfies the total fit, the consistency with fatigue physics and the safety of the tail regions. The utility of the associated methodology is demonstrated by applications to example.

Calculation for Critical Time of Stainless Steel Cladding in Creep Collapse Condition

TIAN Sheng, XIAO Zhong, LEI Tao

2004, 25(6): 514-516.

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In order to keep the integrality of rods for the associated assembly in PWR, the creep collapse of cladding is not permitted. Usually the material of these claddings is stainless steel. A hypothesis sandwich analytical theory is used, and the formulas for calculation of the creep collapse critical time is given in this paper.

Effect of Water Chemistry on Oxide Morphologies of Zircaloy-4

LIU Wen-qing, CHEN Wen-jue, LI Qiang, ZHOU Bang-xin, YAO Mei-yi

2004, 25(6): 517-521.

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To understand the degradation behavior of corrosion resistance in LiOH aqueous solution for Zircaloy-4, Scanning Electron Microscope（SEM） and Scanning Probe Microscope （SPM） are performed to observe the inside and outside surface morphologies of the oxide. Based on the results, it is suggested that there exists compressive stress parallel to oxide/matrix interface in the oxide film because of volume expanding during the oxidation of Zircaloy-4. The oxide film heaves due to compressive stress, which brings strain stress perpendicular to interface, the strain stress leads oxide film break and results in accelerating corrosion rate. The higher the concentration of LiOH aqueous solution is, the quicker the process is.

Thermal Property Measurement of Reactor Control Material Rod Ag-In-Cd

XUE Shu-juan, CHEN Yong, QIU Shao-yu

2004, 25(6): 522-524,533.

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The thermal expansion, specific heat, young’s modulus, thermal diffusivity and conductivity have been measured by differential methods, differential scanning calorimeter, resonance method and laser bombard method in this work. The results are shown as follows: linear thermal expansion coefficient of alloy increases with the increase of temperature, which is 23.26×10^-6℃ ^-1 from 20℃ to 300℃ ; specific heat has little change below 300℃; average specific heat is 0.2583 J/g℃ ; young’s modulus decrease with the increase of temperature, and thermal diffusivity and conductivity increase with the increase of temperature, which are 6.2GPa, 0.30810^-4m²/s and 0.836 W/m·℃ at 300℃, respectively.

Optimization of Feed Water Control for Auxiliary Boiler

LI Ling-mao

2004, 25(6): 525-528.

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This paper described the feed water control system of the auxiliary boiler steam drum in Qinshan phase III nuclear power plant, analyzed the deficiency of the original configuration, and proposed the optimized configuration. The optimized feed water control system can ensure the stable and safe operation of the auxiliary boiler, and the normal operation of the users.

Problem Analysis and Improvement Solution for DVN Negative Pressure Monitoring System

CHEN Yong-hong

2004, 25(6): 529-533.

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During the commissioning of Ling’ao nuclear power station, it was found that abnormal operation in DVN was caused by the unreasonable design in negative pressure monitoring system. This paper emphasizes on the analyzing of how the negative pressure monitoring system works and what is the problem unsolved,and finally introduces the measures and solutions adopted to improve this system.

Realization of Multi-Parameter and Multi-State in Fault Tree Computer-Aided Building Software

GUO Xiao-li, TONG Jie-juan, XUE Da-zhi

2004, 25(6): 534-537.

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More than one parameter and more than one failed state of a parameter are often involved in building fault tree, so it is necessary for fault tree computer-aided building software to deal with multi-parameter and multi-state. Fault Tree Expert System （FTES） has the target of aiding the FT-building work of hydraulic systems. This paper expatiates on how to realize multi-parameter and multi-state in FTES with focus on Knowledge Base and Illation Engine.

Initiating Event Analysis for Probability Safety Assessment of Marine Nuclear Reactors

ZHAO Xin-wen, CAI Qi, CAI Zhang-sheng

2004, 25(6): 538-541.

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According to the characteristics of marine nuclear reactors, the paper studies the method of initiating events analysis for probability safety assessment. Criteria and approaches to grouping initiating events are achieved. Two conceptual models applied for the initiating events frequency calculations are given.

Classification and Experimental Study of Human Cognitive Reliability Model

WANG Yao, GAO Ping-xiao, SHEN Zu-pei, HUANG Xiang-rui

2004, 25(6): 542-545.

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By the simulator experiment for the Qinshan NPP operators, the identification method of parameters and classification of Human Cognitive Reliability model and the analysis method of the response time data are described. It is found that the main factor for classification is the normalized standard deviation, which is a critic parameter of Weibull distribution. Using the classification and analysis method presented in the paper, the cognitive reliability parameters for the Qinshan NPP operators are obtained from the Qinshan simulator experiment data. The result of the Qinshan experiment basically coincides with the IAEA experiment.

Study on Severe Accident Progression Induced by SBLOCA and Mitigation Measures for QINSHAN NPP Unit 1

XU Yi-quan, CHE Ji-yao, SU Yun, CAO Xue-wu

2004, 25(6): 546-549.

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The severe accident, induced by small-break lost-of-coolant accident （SBLOCA） in Qinshan NPP Unit 1, is analyzed by a NPP severe accident simulator developed in this laboratory, based on SCDAP/RELAP5 and PROSYS. By employing the results of USA SAN ONOFRE NPPs IPE and SURRYs PSA, to end the core damage progression and mitigate the consequences of SBLOCA, the primary feed-and-bleed measures for the management of the severe accident induced by SBLOCA is selected, which is verified through the calculation by using the simulator. The results suggest that implementing the feed-and-bleed measures could be available and an effective way to arrest the SBLOCA sequences in Qinshan NPP unit 1.

Study of Inhibitor Containing Ti Through Exposed Experiment and Analysis of Surface Film for Nuclear Steam Generator

XU Qi, HUANG Xin-quan, SU Xing-wan, MA Wei-gang

2004, 25(6): 550-554,570.

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Corrosion of construction material in high temperature water is one of important problems for nuclear reactors. Latest researches show that TiO₂ inhabiting species can alleviate local corrosion, such as Stress Corrosion Cracking （SCC） and Inter-granular Attack （IGA） of steam generator tubes, prolong the life of SG tube. The result of high temperature exposed experiments shows that TiO₂ have positive effect. No SCC was found in 0Cr18Ni10Ti stainless steel after exposure to the 50% caustic solution with inhibitor containing Ti at 288℃ for 1 week. Among them, Rutile and Anatase are more effective than tetrabutyl titanate. But during a longer time （above 2 weeks） of experiment, the inhibitors containing Ti can not prevent SCC. SEM, XRD, XPS were used to analyze the chemical composition and construction of the film formed on the surface of the specimen, and the issue of dealloying was discussed. Depth sputtered XPS figure shows that Anatase can prevent dealloying and control the development of crack along inter-granular. TiO₂ inhabiting species is a new type granular inhibitor, and its application is being paid close attention.

Radioactivity Evaluation Methods for Decommissioning and Calculation of Neutron Spectrum for Main Steam Pipe Room of Fugen

SHEN Jin, YANG Hong-run

2004, 25(6): 555-558.

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The main systems and design parameters of the first prototype ATR （Advanced Thermal Reactor） Fugen of Japan are introduced in this paper. It is also shows the development of decommissioning policy in Japan and the decommissioning technology for Fugen . Based on the calculation for neutron flux distribution and neutron energy spectrum under ¹⁷N（β,n） reaction in main steam pipe room of Fugen by MCNP code and the analysis of the effect of steam density and steam pipe diameter on calculation results, it concluded that the power transient would not effect the neutron distribution in main steam pipe room and the enlargement of the diameter of steam pipe would help to reduce the radiation in cover materials on steam pipe.

Development of Automatic Image Processing and Test Software System for Polyethylene Material

LIU Qi, GE Yi-nan, XU Gui-ping, ZHOU Xin, JIAN Li-juan

2004, 25(6): 559-561,570.

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The automatic image processing and test software system for polyethylene material includes electromachine control, image capture, image registration and image process and analysis parts. This paper introduces the design and development of the software system and describes the application of the software system in the inner defects inspection of the sample. The analysis and experimental results show that the software system is with rational principle and feasible structure, and is reliable for quality control of polyethylene material.

Dynamic Simulation of Control and Protection System in Nuclear Power Plant

LIN Meng, HU Rui, YANG Yan-hua

2004, 25(6): 562-566.

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This paper analyzes models of measuring system, control and protection system, system equipments, equipment failure, and some auxiliary system in CHASHIMA NPP. Program module PROSYS for dynamic simulation of the control and protection system is developed by C language and applied in engineering simulator to dynamically simulate the control and protection system of CHASHIMA NPP. The simulator has been used for NPP safety analysis and to provide support and validation service for the design of advanced main control room. Results show that this simulation software can successfully simulate the control and protection function of primary and secondary loops in NPP.

2004, 25(6): 567-576.

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2004 Vol. 25, No. 6