核动力工程

Cost Analysis of NPP Front-End Fuel Cycle

BO Mei-fang, ZHOU Lin-jun

2010, 31(1): 1-3,8.

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This paper introduces an analytical method to calculate the cost of fuel cycle when a PWR NPP is in dynamic balance.An example using this method to calculate the fuel cycle cost of an AP1000 NPP is given.Sensitive analysis for some prices of the front-end is also given.This paper has a certain reference value in the decrease of nuclear fuel cycle and further the total cost of power generation in PWR NPPs.

Effect of Copper-Enriched Clusters on Mechanical Properties of Pressure Vessel Model Steel of Nuclear Reactors

ZHANG Rui-qian, HONG Xiao-feng, PENG Qian

2010, 31(1): 4-8.

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The precipitation of copper-enriched clusters was induced into pressure vessel model steel（with higher Cu content） of nuclear reactors by water quenching and thermal aging.The mechanical property tests showed that the presence of copper-enriched clusters led to a large shift of the ductile-to-brittle transition temperature,a tiny increase in the yield strength and tensile strength,and a tiny decrease of plasticity.In addi-tion,this paper also studied the effect of the presence of Nickel element on the ductile-to-brittle transition temperature.Three-dimensional atom probe test revealed that the number density of enriched clusters was about 10²³ m^-3,and the size of copper-enriched clusters was in the range of 1nm to 3nm in diameter.

Experimental Study on Thermal Aging Impact Properties of Austenitic Stainless Steel Z3CN20.09M

XUE Fei, SHU Guo-gang, TI Wen-xin, YU Wei-wei, MENG Xin-ming, LIU Jiang-nan, SHI Chong-zhe

2010, 31(1): 9-12.

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The impact property of the centrifugal casting austenite stainless steel Z3CN20.09M no effect on the ratio value Fu/F_m but a significant influence on the impact force and especially on the impact energy.TEM analysis indicates that the shape of dislocations in austenitic has changed,and precipitations have appeared in ferrite.Extrapolation prediction of the impact property is performed by the regression functions established in this study.

Process for Titanium Powders Spheroidization by RF Induction Plasma

GU Zhong-tao, YE Gao-ying, LIU Chuan-dong, TONG Hong-hui

2010, 31(1): 13-17.

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Spherical titanium（Ti） particles were obtained by the process of heating irregularly shaped Ti powders under the radio frequency induction plasma（RF induction plasma） condition.The effect of feed rate,various dispersion methods and Ti particle size on the spheroidization efficiency was studied.The efficiency of the spheroidization is evaluated through the measurements of the percentage of powder spheroidized based on the electron microscopic observations and the tap density measurement of the processed powder.During the short flight of the particles in the plasma flow,of the order of a few milliseconds,the individual titanium particles of the powder are heated and melt,forming a spherical liquid droplet which upon freezing gives rise to the formation of a perfectly dense spherical solid particle.So RF induction plasma is a promising method for the preparation of spherical titanium powders with high flowability.

Transmutation of MA Nuclides in Sodium Cooled MOX Fuel Fast Reactor

HU Yun, WANG Kan, XU Mi

2010, 31(1): 18-22,27.

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The fundamental physics characteristics of Minor Actinides（MA） transmuted in sodium cooled fast reactor are investigated in this paper.The results indicate that addition of MA into fuel will affect the core kinetic parameters and reactivity feedback significantly,for instance,the decreasing of β_eff and DoPpler feedback,and the increasing of sodium void worth.Meanwhile,after MA addition,the reduced burnup reactivity loss,the incineration of considerable amount of MA nuclides,and the energy released by fission of MA nuclides will be benefited.The essential of MA transmutation relies strongly on MA incineration and the specific incineration consumption of MA,which is in direct proportion to MA fission share of whole core（including fission of the daughter nucleus after MA capture reaction）,thus core safety parameters corresponding to the same MA fission share are the key points for the design of a dedicated MA burner.Compared with a lager core,the smaller core,favorable choice for dedicated MA burner,can effectively decrease the sodium void reactivity feedback,while without significant impact on MA specific incineration consumption.

Method of Life Prediction for Low Cycle Fatigue in PWR Primary Pipe Material

XUE Fei, SHU Guo-gang, YU Wei-wei, WEN Xin, LIN Lei, MENG Xin-ming, LIU Jiang-nan

2010, 31(1): 23-27.

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An experimental study on the fatigue behavior of the NPP PWR primary pipe material Z3CN20.09M made in China is performed on a group test of low-cycle fatigue under room temperature and elevated temperature of 350℃.The Manson-Coffin equation,simple tensile prediction model,Ostergren model and three-parameter power function for low cycle fatigue（LCF） are investigated.The prediction results show that the life prediction capability in elevated temperature is weaker than that in room temperature for all models except the simple tensile prediction model.The simple tensile prediction model gives worst results,most of its predictions are on the non-conservative side,while the Ostergren model presents best predictions for room fatigue tests,and the three-parameter power function yields a good result in life prediction for ele-vated temperature fatigue tests.

Experimental Study on Steady and Transient Characteristics of Heat Transfer and Flow for Single-phase Water Flow in Narrow Rectangular Channel

WEN Yan, GAO Chao, QIU Sui-zheng, SU Guang-hui

2010, 31(1): 28-32,37.

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Single-phase water characteristics of flow and heat transfer in steady and transient conditions were experimentally investigated in the horizontal and vertical rectangular channels with the pressure ranging from 0.5MPa to 5.0MPa..The experimental results indicated the characteristics of single-phase water flow and heat transfer in transient conditions were similar to that in steady conditions.So were the experimental results for horizontal and vertical narrow rectangular channels.The single-phase water frictional resistance coefficient in narrow rectangular channel were larger than that of normal channels,and the transition region from laminar flow to turbulence flow had a small Reynolds number relative to conventional channels.The critical Reynolds number at the transition region was in the range900 ≤ Re≤ 1300.Based on Dittus-Boelter correlation,the experimental correlations of heat transfer were obtained,and the coefficients of the new experimental correlations were less about 11.3% than that of Dittus-Boelter correlation.In steady conditions,the heat transfer coefficient at turbulence flow region increased observably with the mass flux,it also increased slightly with the heat flux,and it had slight relationship with the pressure.

Experimental Investigation of Convection Heat Transfer of CO₂ at Supercritical Pressures in a Vertical Circular Tube at Low Re

LI Zhi-hui, JIANG Pei-xue

2010, 31(1): 33-37.

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Convection heat transfer during upward flow of CO₂ at supercritical pressures in a vertical circular tube（d=2mm） at low Reynolds numbers ranged from 750 to 1 970 has been experimentally investi-gated.The results show that the local wall temperature decrease was observed in upward flow at low heat fluxes and the local wall temperature peak at high heat fluxes with upward flow for Re=1970 which were not observed.The trend of wall temperature and the regularity of heat transfer are similar for upward and down-ward flows.

Analysis on Temperature Distribution in Density Lock on Steady State without Disturbance

YU Pei, YAN Chang-qi, GU Hai-feng, CHEN Wei

2010, 31(1): 38-41,48.

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Temperature distribution on steady state without disturbance in density lock is simulated ex-perimentally in this paper,and the temperature stratification end point is discovered on the temperature curve on steady state.It separated the heat conduction layer and homoiothermy layer.Only when the temperaturestratification end point is in the density lock,heat can be restrained effectually.The temperature field is simulated with three methods.The first one is a method of semi-infinite flat-panel heat conduction,the second one is a method of one dimensional steady state conduction in constant cross-section straight-fin,and the last one is calculated using Fluent calculation software.The results indicated that the method of semi-infinite flat-panel heat conduction is the best one to calculate the distribution of temperature and location of temperature stratification end point.

Experiment on Density Wave Oscillation Instability of Two-Phase Flow in Low Mass Velocity Parallel Vertical Rifled Tubes

HUANG Fan, LUO Yu-shan, CHEN Ting-kuan, WANG Hai-jun, LI Chen-fei, DENG Zhi-an

2010, 31(1): 42-48.

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Experimental studies on density wave oscillation instability of two-phase flow in parallel vertical rifled tubes were conducted on two-phase high pressure test loops.The main characteristics of density wave oscillation instability were perceived.In the range of test parameters,the effects of heat flux,pressure,mass velocity,inlet sub-cooling,asymmetric heat flux on the density wave oscillation instability of two-phase Steam-water two-phase flow were explored and analyzed.Based on the test result and using the homogeneous model,the threshold relational expressions of density wave oscillation instability were obtained.

Calculation on Temperature Field of Steam Generator Cavity Concrete Wall in HTR

LIU Sheng, SHENG Xuan-yu, KANG Fang-liang

2010, 31(1): 49-51,56.

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The finite element software ABAQUS 6.7 was used to calculate the field temperature of steam generator cavity concrete wall under normal condition and Component Cooling Water system shut-down con-dition.The calculation result shows that the maximum temperature is lower than that of the temperature limi-maximum temperature is lower than 100℃ after 7 days.The cooling system can provide enough cooling for the concrete wall.

Experimental Investigation of Flow Resistance Characteristics in Small Scale Annuli

FENG Dian-yi, ZHANG Yu-cheng, YI Deng-li

2010, 31(1): 52-56.

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Experimental investigations of water flow friction in horizontal annuli,with gap sizes of 0.540～2.685 mm,were carried out to determine the effect of gap sizes on the flow resistance characteristics,size is above 2.5 mm,flow resistance characteristics accord with normal size annuli.The flow resistance coef-and the test involved the laminar and turbulent flow regimes.The results showed that of the characteristics of the fluid friction resistance of small scale annuli were obviously different with the theoretical results.The critical Reynolds number in small-scale annuli was slightly less than in normal size annul,but when the gap ficient formula of narrow annuli were established based on the experiment results.

Calculation of Reverse Flow in Inverted U-Tubes of Steam Generator during Natural Circulation

YANG Rui-chang, LIU Jing-gong, HUANG Yan-ping, LIU Ruo-lei, TAN Shi-wei

2010, 31(1): 57-60.

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The mechanism of reverse flow in inverted U-tubes of steam generators of pressurized water reactors during natural circulation is analyzed by using the full range characteristic curve of parallel U-tubes.A lumped?distributed model to calculate the reverse flow occurred in inverted U-tubes of real steam genera-a well agreement with that predicted by the model in which normal or reverse flow in each individual U-tube is analyzed,which verifies the reliability of the model developed in this paper.

Calculation of Physical Process Failure Probability of Passive Systems in NDR by Adaptive Monte Carlo Method

XIAO Ling-mei, YU Tao, YU Hong-xing, LI Zhe, TANG Hua-peng

2010, 31(1): 61-64.

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Physical process failure plays a crucial role in the passive systems.Presently,the importance sampling Monte Carlo method is most widely used in the research of physical process failure probability,but it has to rely on the improved first-order second-moment（FOSM）method in searching of design point,and can not avoid the shortcomings of FOSM.The adaptive Monte Carlo method introduced in this paper chooses the important probabilistic distribution function by adaptive method,avoiding the shortcomings of FOSM,improving the sampling efficiency and the accuracy.Taking the passive system of nuclear desalination reactor（NDR） for an example,this paper evaluates the physical process failure probability by the adaptive Monte Carlo method and the presently used methods,and then compares and analyzes the adaptiveness of various methods on the passive systems.

Application of Forward FTF Method in Failure Analysis of Pilot-Operated Safety Valve

YANG Tian, ZHOU Mi, XIE Jun, HUANG Wei-xing, LUO Zhi-yuan, LI Xiao-zhong

2010, 31(1): 65-69.

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On the basis of studying the characteristics of Failure Modes,Effect and Criticality Analysis（FMECA） method and Fault Tree Analysis（FTA） method,a forward FTF method which integrates FMECA with FTA is built to analyze the failure of the nuclear Pilot-Operated Safety Valve.It is a comprehensive and exhaustive method which has considered the integrative effect caused by every function failure mode,hardware,software,artificial factor,environment and multiple failure modes.Through the qualitative analysis of the valve failure mode with the method,the most important failure modes of the valve system and important parts are found.A feasible method for failure analysis of the valve system is provided in this paper.

Reliability Analysis for Structure Strength of Metal O-ring Based on Probability Finite Element Method

ZHOU Mi, XIE Jun, YANG Tian, ZHANG Dong-lin, JIANG Sheng-han, LI Xiao-zhong

2010, 31(1): 70-73,78.

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Metal O-rings was required as a high reliability sealing element in the safety valve for the ap-plication in nuclear power plants.The finite element model for the metal O-rings was constructed with the method of elastoplastic contact analysis based on the ANSYS software.The deformation and equivalence stress distribution of the metal O-rings have been obtained.The Probabilistic Finite Element Analysis for the Structure Strength of Metal O-ring has been done with the ANSYS Probabilistic Design System（PDS）.The analysis result indicates that the strength of the O-ring has high reliability.The strength limit of the material is the most important stochastic input parameter.The reliability of the O-ring can be improved by decreasing the dispersion of the property parameters of the material.

Analysis of Mitigation Capability of High-Pressure Safety Injection System to SBO Accident for PWR

XU Jin-liang, ZHANG Da-fa, ZHANG Long-fei

2010, 31(1): 74-78.

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Taking a typical three-loop PWR as the reference plant and using the best estimate computer code RELAP/SCDAPSIM /MOD3.2,a representative three loops PWR severe accident calculation model is established and station blackout（SBO） induced core melt progression is analyzed.The mitigation capability of high-pressure safety injection system to severe accident is studied.The sensitivity calculation results show that the severe accident management strategy of bleed-and-feed cooling when the core outlet temperature reaches to 920 K can prevent the core damage effectively and the reactor core can achieve a long term safe stable state.

Pattern Recognition Technology in Fault Diagnosis of Electrical Safety Valve Level

YANG Guo-feng, HU Shou-yin

2010, 31(1): 79-82,87.

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In this paper, the safety grade electric isolation valve fault detection system was used for the valve fault detection, and the pattern recognition technology was adopted to identify the fault types. Real-time faults were analyzed and identification results were given. Tests show that this diagnostic method is simple and effective, and with detailed characterization of various fault types and precise fault identification.

Analysis of Boron Acid Concentration Drop during Power Changing Process

YE Guo-dong, DAI Qian-jin, YANG Shao-jie, PAN Ze-fei, ZHAN Yong-jie, HE Zi-shuai, ZHANG Jiao

2010, 31(1): 83-87.

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Boron acid is very important to the control of the nuclear power station. The boron acid concentration drop has been analyzed and explained by using the reactivity balance formula. The conclusion is that the dynamic poison is the main reason. This paper is a good reference and guideline for the boron acid concentration management in the nuclear power station.

Application of SIMULINK Simulation Technology in PWR Purification System Reliability Analysis with GO Methodology

HUANG Tao, CAI Qi, ZHAO Xin-wen, XIE Hai-yan

2010, 31(1): 88-91.

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This paper studies how to apply GO Methodology to the process of system reliability calcula-tion.The GO algorithm calculation simulator was constructed with SIMULINK.And the final results show that the whole process can be greatly simplified by applying SIMULINK to it and the shared signals to system reliability have to be considered.

Experimental Research on Effect of Vertical Oscillation on Temperature Field in Density Lock

WANG Sheng-fei, YAN Chang-qi, GU Hai-feng, FANG Hong-yu

2010, 31(1): 92-96,101.

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Experimental studies and analysis of temperature field with vertical oscillation in density lock are carried out. By comparison of the temperature field changes before and after the oscillation, the effect of amplitude and temperature difference on temperature field with vertical oscillation is analyzed. The results shows that, the temperature fields in density lock will move upward because of vertical oscillation, and the offset increases with the amplitude increase and decreases with the temperature difference increases; however, once the oscillation stopped, the temperature field will return to the initial state gradually.

Development of Loose Parts Monitoring System for Nuclear Power Plants

LIU Cai-xue, WANG Cheng-yuan, ZHENG Wu-yuan, LI Xiang, DENG Sheng, HU Jian-rong, JIAN Jie

2010, 31(1): 97-101.

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The loose part monitoring system developed for Qinshan Nuclear Power Phase II Extension Project is able to monitor three regions, which comprises ten monitoring channels and monitors the loose parts in RPV and SG. Several modern techniques are applied in the system, for instance, FPGA are adopted in sig-nal preprocessing and alarm processing, the DSP is applied in loose parts event discriminating, which includ-ing the real-time short RMS compared with floating long RMS, time delay, alarm channels check, and etc. These virtues make the system a powerful capacity of anti-misinformation. DAQ instead of tape recorder en-sures the integrality of data log. The synchronization of PXI bus meets the need of the locality analysis. The techniques of virtual instrument and database management provide an open entry for the diagnose of loose part events, and the display turns to more visual. In addition, the system had other useful functions, such as fault channels self-testing and shutting, disk space checking and software protecting as soon as power-off.

Analysis and Research on Fuel Cladding Failure Monitoring Based on Floating Alarm Threshold

YUAN Bin, LIU Cai-xue, HUANG Wen-lou, LING Qiu

2010, 31(1): 102-106.

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Considering the shortcomings of traditional fixed threshold set as alarm threshold for fuel cladding failure monitoring, this paper puts forward the concept of floating alarm threshold and carries on a preliminary study on floating alarm threshold setting, based on mathematical statistical and probabilistic analysis method. The study shows that during fuel cladding failure monitoring, floating alarm threshold can monitor the condition of fuel cladding failure in a more accurate way and at a higher speed and alarm in time.

Fault Tolerant Control for Steam Generators in Nuclear Power Plant

DENG Zhi-hong, SHI Xiao-cheng, XIA Guo-qing, FU Ming-yu

2010, 31(1): 107-111,116.

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Based on the nonlinear system with stochastic noise, a bank of extended Kalman filters is used to estimate the state of sensors. It can real-time detect and isolate the single sensor fault, and reconstruct the sensor output to keep steam generator water level stable. The simulation results show that the methodology of employing a bank of extended Kalman filters for steam generator fault tolerant control design is feasible.

Design of Multi-Point Automatic Positioning Preprogrammed Crane Control System

LI Zi-qiang, LI Guang-jian, PAN Long-xuan

2010, 31(1): 112-116.

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This automatic positioning system is designed for the crane which is in common use. The crane hall is cut into several parts, the position is detected by the photoelectric switches, and the PLC and inverter are used for the control devices. The automatic positioning control of the crane is completed by means of the timing movement. The positioning error is less than 2.1cm, the swing range when lifting object is less than 5.7cm, and the average speed of the crane is more than 90% of the rated speed. This paper gives further description in the positioning control, direction control, speed control and the identification of the starting point. Finally it gives an analysis of the automatic positioning performance.

Development of Real-Time Multitask OSS Based on Cognitive Task Analysis

WANG He, CHENG Shou-yu

2010, 31(1): 117-121.

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A Real-time Multi-task Operator Support System （RMOSS） has been developed to support the operator’s decision making process in the control room of NPP. VxWorks, one embedded real-time operation system, is used for RMOSS software development. According to the SRK modeling analysis result of the operator’ decision making process, RMOSS is divided into five system subtasks, including Data Collection and Validation Task （DCVT）, Operation Monitor Task （OMT）, Fault Diagnostic Task （FDT）, Operation Guideline Task （OGT） and Human Machine Interface Task （HMIT）. The task test of RMOSS has been done in a real-time full scope simulator. The results showed that each task of RMOSS is capable of accomplishing their functions.

Detailed Modeling and Transient Analysis for Nuclear Power Plant Turbine

SU Geng, LIN Meng, YANG Yan-hua, HOU Dong

2010, 31(1): 122-126,130.

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This paper takes the turbine in Ling’ao phase I nuclear power plant as a prototype, and details the numerical model of the turbine based on RELAP5. The calculation under the stable operation condition at 100% power indicates that the detailed turbine numerical modeling remedies the larger calculation error for the enthalpy values by simplified modeling. The detailed turbine numerical modeling is incorporated in the thermodynamic system model for the whole nuclear power plant to conduct the transient analysis, and comparison with the data curves under the step power change from 97% to 87% of the turbine load in the original test report is carried out. The results showed that the error between the enthalpy calculation value for the steady-state model and the actual value of the plant is within 2%, and the analysis parameters for the transient model are in line with the actual situation of the nuclear power plant.

Experimental Study on Irradiation Effect of Silicon Commutation Diode on CFBR-Ⅱ Neutron Field

QIU Dong, ZOU De-hui

2010, 31(1): 127-130.

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The neutron irradiation damage constants of typical silicon commutation diodes have been measured, and its irradiation damage rule of forward voltage v.s. neutron flux has been verified based on CFBR-II neutron filed. The experiment results indicate that the damage constants of silicon commutation diodes range from 3×10^-15 V·cm^-2cm² to 4×10^-15 V·cm^-2, and the forward voltages grow exponentially with the neutron flux.

Safety Control and Minimization of Radioactive Wastes

WANG Jin-ming, RONG Feng, WANG Xin, LI Jin-yan

2010, 31(1): 131-135.

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Compared with the developed countries,the safety control and minimization of the radwastes in China are under-developed.The research of measures for the safety control and minimization of the radwastes is very important for the safety control of the radwastes,and the reduction of the treatment and disposal cost and environment radiation hazards.This paper has systematically discussed the safety control and the minimization of the radwastes produced in the nuclear fuel circulation,nuclear technology applications and the process of decommission of nuclear facilities,and has provided some measures and methods for the safety control and minimization of the radwastes.

Determination of Boron Isotope Ratios in Boron Carbide by Mass Spectrometry

YANG Bin, DENG Hui, LIANG Bang-hong, ZHANG Ge

2010, 31(1): 136-139,142.

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This paper introduces the direct determination of boron isotope ratios in the boron carbide powder by thermal ionization mass spectrometry. The technique for sample loading, the procedure for heating and the eliminating of effects induced by oxygen are studied. The study indicates that the preparing process for the sample will be shorted, and the time for determination and the exposure dose of the laboratory assistant will be reduced for the reason of directly determination of boron carbide.

Measurement of Radiation Damage Constant about Bipolar Transistor of CFBR-Ⅱ

ZOU De-hui, QIU Dong

2010, 31(1): 140-142.

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This paper describes the measurement of radiation damage constant of typical bipolar transistor of CFBR-II in a steady state,in order to acquire the radiation damage equivalent coefficient between CFBR-II and the others.The results show that the radiation damage constants of silicon bipolar transistors are between 4×10^-16cm² and 6×10^-16cm²,and for the range of linearity about current gain following neutron fluence,the collector current can be expanded to 300 mA.

2010 Vol. 31, No. 1