核动力工程

Study on Application of Zirconium Diboride（ZrB₂） in CPR1000 Quarter-Core Fuel Management

LI Jinggang, LU Haoliang, ZHANG Hong, ZHU Yanan, CHEN Mingan

2012, 33(5): 1-5.

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Abstract:
Using the SCIENCE V2 code package,the assembly reactivity of ZrB₂ and gadolinium oxide,and the core peaking factor,cycle length and shutdown margin of the core loaded with these two different burnable poisons are analyzed for CPR1000 quarter core fuel management mode.The results show that it is feasible to load the fuel assemblies with ZrB₂ burnable poison in CPR1000 quarter-core fuel management mode,and a longer cycle length can be obtained.

Improvements of Interval Bound Algorithm for Reactor Reloading Pattern Optimization and Their Verifications

GONG Zhaohu, YAO Dong, WANG Kan, WANG Mingli

2012, 33(5): 6-11.

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Interval Bound Algorithm is a well performance algorithm to optimize reactor reloading pattern problem.In order to improve the performance of the algorithm further,this paper added "elitism strategy" to it.The numerical result showed that the improved algorithm became better than the basic algorithm in terms of both solution quality and convergence speed.Moreover,in order to solve multi-modal reloading pattern optimization problem,the multi-interval-model was added to the algorithm.The numerical result also illustrated that the re-improved algorithm was able to find multi-modal optimization solutions simultaneously without increasing of calculation load.With the two improvement measures,Interval Bound Algorithm has performed better in realistic application.

Research on Decay Heat Calculation and Measurement for Pool-Type Research Reactor

HUANG Hongwen, LIU Hangang, MI Xiangmiao, QIAN Dazhi, YANG Xiaobin, HUANG Wen, ZHANG Zhihua

2012, 33(5): 12-15,21.

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The heat-measurement method is adopted to measure the decay heat of a nuclear reactor during 45.0 hours after the rated power operation of 75.0 hours;an empirical formula is fitted according to the experimental data.Several calculation empirical formulas used to calculate the residual power of a nuclear reactor and comparison with the test result indicated that the heat-measurement method could be used to measure the decay heat of a reactor,and the data is conformed to the standard of EJ/T 745.

Development and Validation of Multi-Group Cross-Section Library for Subcritical Energy Reactor

MA Jimin, LIU Yongkang, LI Maosheng

2012, 33(5): 16-21.

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As the fusion-driven subcritical energy reactor has wide and complex energy spectrum,multigroup cross-section library needs to be developed for its design requirement.A 187-group neutron cross-section library is developed by using NJOY code.With transport code ANISN,enriched uranium critical sphere benchmarks and uranium sphere model with water cavity are calculated to validate the multigroup cross-section library Multi-layer shell model of subcritical energy reactor is calculated,and the results are compared with MCNP5.The results show that the multigroup cross-section library is correct and can be used for subcritical energy reactor design,and the reaction rates and neutron spectra in subcritical energy reactor can be calculated as well.

Effect of Blocking Mass on Characteristics of Beam Lateral Vibration

LI Pengzhou, LU Jun, SUN Lei

2012, 33(5): 22-25,31.

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The lateral vibration equation is established by setting up two separate co-coordinate systems of the mass-beam system,and the non-dimensional coefficients implying the position and mass radio of the mass in the system are presented in the paper.The effect on the vibration frequencies of changing the position and the mass radio in the system is numerically discussed,and the modes of the system with different mass radio and position are considered.The result shows that the frequencies decrease as increasing the mass radio,but the frequencies fluctuate with position changing,and there exists some positions that the frequencies do not vary after the mass radio increases except the first frequency,also that the effects on the vibration characteristic as increasing the mass radio can be decreased by modulating the position of the mass.

Study on J-Integral Tearing Modulus Inter-Section Method in LBB Technology

QIAO Hongwei, LIU Zhiwei, LI Xihua, ZHANG Yong, LI Qi

2012, 33(5): 26-31.

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J-integral tearing modulus inter-section method（J-T） for limit load and critical crack length calculation in LBB technology is introduced.J-integral of cracks with three kinds of crack length are calculated by finite element program ABAQUS firstly,then the relationship between J-integral and crack length is surrogated by a polynomial,and the limit load and critical crack length are obtained based on the polynomial at last.The validity of the J-T method is checked by an example provided by FLET program.The results demonstrated that precision of unstable J-integral calculation is improved by the ABAQUS-based J-T method,and the proposed method is more universal and suitable for the LBB analysis of complex structures.

Study on Crack Leak Quantification of Pressure Pipeline

HE Pan, LIU Caixue, WANG Yao, AI Qiong, SONG Jian

2012, 33(5): 32-35.

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Based on the analysis of attenuation characteristics of leak acoustic emission signals,the attenuation constant and the correlation with leak rate are obtained by the experiment of pipeline crack leak.The calculation method of crack leak rate for pressure pipeline is presented.The experiment shows that the method is effective for crack leak quantification of pressure pipeline.

Numerical Research of Ductile Crack Growth Behavior for Dissimilar Metal Welded Joint of Nuclear Pressure Vessel

WANG Haitao, WANG Guozhen, XUAN Fuzhen, LIU Zhangjun, TU Shandong

2012, 33(5): 36-40.

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Based on GTN damage model and finite element method（FEM）,numerical simulations are performed on the specimens of a nuclear power dissimilar metal welded joint（DMWJ）,and the crack growth paths and J-R resistance curves were obtained.Results show that the crack growth paths for the central cracks in the buttering and weld material are nearly the same as those of the homogenous material crack,while the growth paths for interface crack and near interface crack in the DMWJ deviate from their initial positions significantly.The initial interface crack and near interface crack tend to grow in the soft material with low yield stress,and is mainly caused by the strength mismatch of the different materials.The cracks with different initial location and depth have different strength mismatch and geometry constraint,and result in different J-R resistance curves.The growth paths and resistance curves of these cracks could not be predicted by macroscopic fracture mechanics;while the numerical simulation of finite element based on GTN damage model is expected to be used in structural integrity assessment for safe-end DMWJ and leak-before-break analysis.

Improvement of Relap5/Mod3.2 Based on High-Pressure Horizontal-Stratified TPTF Experiment

HE Shuangji, JIE Heng

2012, 33(5): 41-44.

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The calculation of Relap5/Mod3.2 and Two Phase Test Facility（TPTF,Japan） experiment data is compared,which shows that Relap5 gives some derivation of void fraction distribution in the horizontal pipe.The analysis reveals that the horizontal junction flow regime of Relap5 has some error on the transition region and the transition equation of the horizontal-stratified flow regime,resulting in Relap5 mistaking some stratified condition as other condition.After modifying the transition region and the interphase drag equation on the transition region,new results from new Relap5 have been improved compared with the experiment data.

Experimental Investigation on Water Film Behavior Falling on Vertical Plate

SONG Jian, YU Yiqi, YANG Yanhua

2012, 33(5): 45-49.

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In this paper,experimental studies on falling water film behaviour on vertical flat plat are carried out in WABREC apparatus.The Reynolds number ranges from 50 to 900.Capacitance probes and high speed camera are adopted to measure the water film thickness and wave velocity.The data are compared with the theoretical solutions and other experiments available in the open literature,and good agreement is obtained.Experimental results on film thickness,its probability density function and wave velocity are presented and discussed.

Identification of Complex Model Thermal Boundary Conditions Based on Exterior Temperature Measurement

LU Jianming, OUYANG Guangyao, ZHANG Ping, RONG Bojun

2012, 33(5): 50-53,68.

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Combining the advantages of the finite element software in temperature field analyzing with the multivariate function optimization arithmetic,a feasibility method based on the exterior temperature was proposed to get the thermal boundary conditions,which was required in temperature field analyzing.The thermal boundary conditions can be obtained only by some temperature measurement values.Taking the identification of the convection heat transfer coefficient of a high power density diesel engine cylinder head as an example,the calculation result shows that when the temperature measurement error was less than 0.5℃,the maximum relative error was less than 2%.It is shown that the new method was feasible

Analysis on Circumferential Non-Uniformity in Heat Transfer Behavior of Supercritical Water in Smooth Square Annular Channel

ZHU Haiyan, YAN Xiao, ZENG Xiaokang, LI Yongliang, HUANG Yanping, XIAO Zejun

2012, 33(5): 54-58.

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Numerical simulations of heat transfer to supercritical water in smooth square annular channel have been performed using fluid-solid coupling method.The simulation results indicated that the heat wall temperatures are non-uniformity on the circumference,and the temperature of inside heat wall is more uniform than the outside wall.It has been found that the average temperature of outside wall can be derived from the average temperature of inside wall using the one dimension differential equation.The temperature of the narrow channel reach the pseudo-critical point before the corner channel,which induce the circumferential non-uniformity of temperature on the outside wall varies along the axial distance and exhibits three regions with different patterns.Compared with the heat volume boundary condition,the heat flux boundary condition predict higher non-uniformity of wall temperature,which indicate the heat conduction in the solid domain smoothes the circumference temperature curve of the heat wall.

Theoretic Study on Density Wave Oscillation in Two Parallel Channels

LIU Yanjun, SUN Yufa, YAN Xiao, XIAO Zejun, ZHAO Hua

2012, 33(5): 59-63.

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In the present paper,a linear analysis of Density Wave Oscillation（DWO） in two parallel channels using a lumped parameter model is established.The effect of some thermal-hydraulic parameters,such as system pressure,mass flow velocity and inlet subcooling,on DWO is theoretically analyzed.The results show that within a certain range and with constant thermal data,the increasing of the system pressure,mass flow velocity or inlet subcooling enhances the system stability,and the increasing of inlet resistance can also improve the system stability,but the increasing of outlet resistance will impair the system stability.

Effect of Heaving Motion on Bubble Diameter Distribution in Narrow Rectangular Channel

HONG Gang, YAN Xiao, YANG Yanhua, XU Jianjun, XIAO Zejun, HUANG Yanping

2012, 33(5): 64-68.

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In order to investigate the phase distribution in subcooled boiling under heaving condition,a visual study on forced convection subcooled water boiling experiments were conducted in narrow rectangular channels at low frequency heaving motion.Bubble diameter had been determined from high-speed digital video camera and image processing.The results show that the increasing of the frequency of heaving motion causes the increasing of bubble diameter fluctuation.Under the same heaving condition,the increasing of mass flow rate leads to the decreasing of bubble diameter fluctuation.A correlation has been sought for the fluctuation of bubble diameter due to heaving motion.The proposed model agreed with the experimental data within the averaged relative deviation of ±19.1%.

Analysis of Operators’ Diagnosis Tasks Based on Cognitive Process

ZHOU Yong, ZHANG Li

2012, 33(5): 69-75.

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Diagnosis tasks in nuclear power plants characterized as high-dynamic uncertainties are complex reasoning tasks.Diagnosis errors are the main causes for the error of commission.Firstly,based on mental model theory and perception/action cycle theory,a cognitive model for analyzing operators’ diagnosis tasks is proposed.Then,the model is used to investigate a trip event which occurred at crystal river nuclear power plant.The application demonstrates typical cognitive bias and mistakes which operators may make when performing diagnosis tasks.They mainly include the strong confirmation tendency,difficulty to produce complete hypothesis sets,group mindset,non-systematic errors in hypothesis testing,and etc.

Effect of Check Valve on Consequences of Coolant Pump Rotor Seizure Accident for EPR Reactor

CHEN Qiuyang, ZHOU Yonghui

2012, 33(5): 76-78,95.

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Counter current flow phenomenon would appear during reactor coolant pump rotor seizure accident.Present work analyzes the coolant pump rotor seizure accident for European Pressurized Reactor（EPR）.The accident safety analysis results of model with check valve and without check valve are compared.It can be found that the check valve can increase the core inlet flow rate of model about 4%.The increasing of coolant flow rate is beneficial to the reactor core cooling.Check valve can increase the minimum departure from nucleate boiling ratio（DNBR）,reduce the departure from nucleate boiling（DNB） fraction and the fuel rod cladding temperature about 14℃ during coolant pump rotor seizure accident.The analyses results show that the model with check valve can maintain the integrity of nuclear fuel rod effectively during reactor coolant pump rotor seizure accident.

Human Factors Reliability Model of Half-Digital Human-Machine Interface During Diagnosing Process Based on Hide MarKov in Nuclear Power Plants

JIANG Jianjun, ZHANG Li, WANG Yiqun, DAI Licao, PENG Yuyuan, LI Pengcheng, ZHOU Pingping

2012, 33(5): 79-82,128.

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Taking the nuclear power plant as the reference background,the authors propose a particular hide Markov model for diagnosing process with human factors.The model comprises of three assessment parts.For each part,the authors come up with specific function in order to assess human factors error probability of diagnosing process.The proposed methods are tested by experiments.From results of experiments,we can easily see that human factors error probability is precise and reliable in the model,the proposed method is more accurate than a single Weibull function,and that neural network predictive functions that are more suitable are obtained in diagnosing process.The method can be applied to human factors reliability analysis in nuclear power plant emergency.

On Hyperparameter Estimation Methods for Generic Database of PSA

HE Jie, ZHANG Binbin

2012, 33(5): 83-86.

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It is usually difficult to determine the hyperparameters of components for reliability generic database involved in nuclear power plant PSA.Meanwhile,inaccurate hyperparameter values adversely impact the uncertainty analysis of core damage frequencies and Bayesian updating of component reliability parameters.To seek a solution,with empirical Bayesian approach,research was performed on the statistical models and parameter estimation methods that help to build the reliability generic database from the component failure records.The mathematical mechanisms behind the method of moment estimation and the maximum likelihood method were the focus of discussion,with an example demonstrating the application of these two methods.

Design of Mobile Receiving and Treatment Equipment for Radioactive Liquid Waste

KONG Jingsong, LU Jingbin, GUO Weiqun

2012, 33(5): 87-90.

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The advantage and disadvantage of radioactive liquid waste treatment technology are analyzed in this paper.The experimental disposal equipment for radioactive liquid waste with complicated sources is designed by combining the far infrared calefaction technology with evaporation technology.It has advantages of low energy consuming and high decontamination efficiency.The frothy and dirt appear rarely in this equipment.

Numerical Study on Performance of Primary Steam Separator in Steam Generator

LI Ping, YANG Fujun, CHEN Xiaolong, YAO Weida, XIE Yongcheng

2012, 33(5): 91-95.

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The simulation is conducted on primary steam separator in steam generator of nuclear plant by using two-fluid model based on CFD theory.The effects of mass flow rate of water and swirl vane configuration on the separation efficiency,circulation ratio,humidity and pressure drop performance were investigated.The results show that the pressure drag decreases with the increasing of blade angle,30 degree blade angle corresponds the best separation efficiency and lowest humidity.Meanwhile,there is an optimum blade fixing position.

Study on Refueling Flow Field of CITP-Ⅱ Tritium Production Irradiation Device

ZHANG Zhihua, MI Xiangmiao, YE Lin, LIU Zhiyong, LI Rundong, DENG Yongjun

2012, 33(5): 96-99.

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The paper introduces the structure of CITP-Ⅱtritium production irradiation device,presents the basic process of refueling breeders,studies the device’s Solid-Gas phase flow,and computes the flow field parameters,such as pressure,velocity,and buoyancy.The result shows that the reliable structural design and reasonable gas differential pressure could realize the online refueling of irradiation device.

Development of Digital Instrument and Control System on Fast Neutron Critical Assembly

LI Meng, BAI Zhongxiong, XIANG Weiling, LU Yi, JIANG Zhiguo, YE Cenming, ZHANG Yi, RONG Ru

2012, 33(5): 100-106.

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The digital Instrument and Control System is developed based on SOPC（System on Programmable Chip）,virtual instrument and FCS（Fieldbus control system） technology have applied to two fast neutron critical assemblies.The system controls the start-up,running and stopping of critical assembly and measures real time period-reactivity,proliferation-reactivity,power,temperature,and etc.It can alarm and do safeguard function in abnormal status.The results of experiments for more than two years show that the system achieves the design goals.

Design of Core Cooling Monitoring System Based on SOP

HE Zhengxi, YU Junhui, LI Xiaofen, GOU Tuo

2012, 33(5): 107-110.

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Ling’ao phase II nuclear power project is the first SOP adopted plant in China.According to the requirement of this procedure,Core Cooling Monitoring System（CCMS） shall perform two of six status function monitoring tasks of SOP,including primary loop coolant inventory,pressure and temperature.Inventory is monitored by reactor vessel level and the rest are monitored by saturation margin.To fulfill these tasks,the system design,including sensors,data processing and information display,is significantly different from EOP design.This paper gives a generally description from the system design aspect.

Optimization of Large-Scale Double Suction Pump with Semi-Volute Suction Chamber

FU Qiang, YUAN Shouqi, WANG Xiuli, ZHU Rongsheng

2012, 33(5): 111-115.

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In order to perfect internal flow law of double suction pump with semi-volute suction chamber and improve its anti-cavitation performance and efficiency,numerical simulation was conducted on the three dimensional steady turbulent flow in the whole flow passage of semi-volute suction chamber.The impact on hydraulic performance of double suction pump with semi-volute suction chamber by guide plate is analyzed.And result was obtained by contrasting three kinds of semi-volute suction chambers with structural differences.Using standard k-ε turbulent model and based on the Navier-stokes equation,numerical simulation and analysis were conducted by SIMPLEC method and commercial CFD software CFX.By numerical computation,the velocity and pressure distributions of the interior flow field was analyzed,which revealed the flow principle inside the semi-volute suction chamber,the hydraulic performance and the hydraulic losses of double suction pump with semi-volute suction chamber was obtained.The results show that the offset guide plate can improve the internal flow law of semi-volute suction chamber,and can reduce the imports of the vortex impeller and hydraulic loss.Finally,the application examples from practical tests favorably validated the result s of simulation,,which provide theoretical basis for improving the design.

Design and Test of 4πβ-γ Coincidence Measurement Device Based on DSP Technology

ZENG Herong, FENG Qijie, LENG Jun, QIAN Dazhi, BAI Lixin, ZHANG Yiyun

2012, 33(5): 116-119.

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The paper illustrates the hardware and software of the 4πβ-γ coincidence measurement device based on DSP technology in detail.In such device,the single-channel analyzer,gate generator,coincidence circuit and scalar in the traditional coincidence measurement device are replaced by the digital coincidence acquirer which is researched and manufactured by ourselves.Doing so,the measurement efficiency will be respectively improved,and the hardware cost will be lowered.The comparison experiment shows that the design of such device is a success.

Analysis of Cold Crack of AP1000 Steam Generator Tube Sheet Cladding

ZHENG Zhangli, WU Zhiyuan, CAO Ding

2012, 33(5): 120-123.

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This paper discusses the causes of AP1000 Steam Generator（SG） tube sheet underclad cracking.Base metal weldability,hydrogen influence,welding techniques and weld residue stresses are all discussed in details in contributing to the underclad cracking problems.Feasible and realistic improvement plans are proposed for the AP1000 SG tube sheet cladding,including the controlling forging procurement,welding process and cladding techniques.

Fatigue Behavior of Titanium Alloy Ti-4Al-2V under High Cycle Loading at Elevated Temperature

ZHOU Haibin, XIONG Ru, LIU Guiliang, LI Chuanqian, LIU Hong, ZHANG Liang

2012, 33(5): 124-128.

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The high cycle fatigue behavior of titanium alloy Ti-4Al-2V rods with near α phase at elevated temperature（350℃） was evaluated.The traditional high cycle fatigue（HCF） tests with groupspecimen as well as the up-and-down tests were performed under bending and rotating loadings at 350℃ in air atmosphere.The experimental data were analyzed and the theoretical S-N curve,the P-S-N curve and the S-N curve for nuclear design were processed,and the fracture morphology was analyzed by SEM.The results indicate that Ti-4Al-2V rods have good resistance to high cycle fatigue and the value is 339 MPa which is slightly higher than the calculated value from the corresponding equation,and elevated temperature accelerated the oxidation of the specimen which decreased the fatigue duration when compared with the result obtained at low temperature which is around 394 MPa.

Investigations on Selection of Method to Fit Lab-Test Fatigue Life Curve

XIAO Jun, QIU Shaoyu, CHEN Yong, XIONG Ru

2012, 33(5): 129-132.

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The scatter of fatigue life is a factor considered for fitting lab-test fatigue life curves.By leading into diversity coefficient CR,the rule of selection of method to fit lab-test fatigue life curve was established with the value of maximum CR correspond to kinds of S/N the experiment used.Lab-test fatigue life data was fitted to curves according to the rule,and it indicates that the rule can improve the curve fitting.

Research on Number of Insoluble Impurities from Second Side of Steam Generator

AN Run

2012, 33(5): 133-135.

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According to the practical working principle of vertical inverted U-shaped tube natural circulation steam generator（SG）,mathematic model of the number of impurities from the second side of SG was established,and the specific functional relationship between the number of insoluble impurities from the second side of SG and the water and sewage flow was given.The result indicates that the number of insoluble impurities from the second side increases on the basis of the exponential function,with certain limit value,under the condition that the continuous operation of SG reaches around 15 full power days,the number of insoluble impurities from the second side is close to the maximum value,and the emission of impurities of the sewage pipe increases with the increase of the density（amount） of impurities from the second side,until it nearly equals the amount of impurities entered into SG.

Status of Advanced Small Pressurized Water Reactors

CHEN Peipei, ZHOU Yun

2012, 33(5): 136-139.

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In order to expand the nuclear power in energy and desalination,increase competitiveness in global nuclear power market,many developed countries with strong nuclear energy technology have realized the importance of Small Modular Reactor（SMR） and initiated heavy R＆D programs in SMR.The Advanced Small Pressurized Water Reactor（ASPWR） is characterized by great advantages in safety and economy and can be used in remote power grid and replace mid/small size fossil plant economically.This paper reviews the history and current status of SMR and ASPWR,and also discusses the design concept,safety features and other advantages of ASPWR.The purpose of this paper is to provide an overall review of ASPWR technology in western countries,and to promote the R＆D in ASPWR in China.

Preliminary Analysis of Graphite Dust Motion in Helium Mainstream for HTR

PENG Wei, YANG Xiaoyong, YU Suyuan, WANG Jie

2012, 33(5): 140-144.

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Taking the graphite dust in helium mainstream in the primary loop of HTR as an example,the stresses acting on the single graphite dust in the helium mainstream is preliminarily calculated and analyzed.The result indicated that the gas drag played an absolute leading role.Based on the understanding of the importance of gas drag,a simplified motion equation of graphite dust was obtained,which was used to analyze the processes of graphite dust under various conditions.The results show that under a constant mainstream velocity,graphite dust particle velocity will approach the velocity of mainstream with the law of a negative exponent;while when the mainstream velocity changed linearly with time,the speed difference between graphite dust particle and mainstream will tend to a constant value;under the helium turbine cycle in HTR,the acceleration speed of graphite dust depended on the power.

2012 Vol. 33, No. 5