核动力工程

Research on Coupling of Neutronics and Thermal-Hydraulics for Solid Fuel Molten Salt Reactor

Peng Yu, Zou Yang, Dai Ye, Xu Hongjie, Zhu Guifeng

2017, 38(2): 1-5. doi: 10.13832/j.jnpe.2017.02.0001

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Abstract:
Based on the neutronics calculation code package SRAC and the computational fluid dynamics code CFX,a code system SCBAT coupling neutronics with thermal-hydraulics for solid fuel molten salt reactor at steady state was developed.SCBAT transfers data between SRAC and CFX to realize the neutronics and thermal-hydraulics coupled calculation.Power density field result from SRAC can be passed to CFX-Solver to give a user-specified source term and temperature field result from CFX can be passed to SRAC input file by SCBAT.Meanwhile,SCBAT can realize the burn up calculation with critical search using the control rods.SCBAT validity was verified by module.SCBAT application in 10 MW solid fuel molten salt reactor was studied.

Research on Selection of Burnable Poisons for Long-Life Reactor Core

Huang Shien, Yang Ping, Wang Liangzi, Ni Dongyang, Chen Zhang, Ju Haitao, QiN Dong

2017, 38(2): 6-10. doi: 10.13832/j.jnpe.2017.02.0006

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Aiming the needs of long-life core,this paper studied the selection of both integrated type burnable poisons and separated type burnable poisons,and also studied the matching of different types of burnable poisons.The results show that:the burnable poisons with lower burnup rate,such as erbium and hafnium,are more suitable for the integrated type;the burnable poisons with higher burnup rate,such as gadolinium and boron,are more suitable for separated type;and the performance of long-life core can be enhanced through a proper matching of burnable poisons with low and high burnup rate.

Benchmark Verification of Fuel Assembly Few Group Parameter Calculation Code KYLIN-1

Chen Zhang, Zhang Zhizhu, Ju Haitao, Yao Dong, Huang Shien, Ni Dongyang

2017, 38(2): 11-14. doi: 10.13832/j.jnpe.2017.02.0011

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The verification and validation of the reactor fuel assembly few group parameter calculation code KYLIN-1 have been made by the analysis of IAEA benchmark problem with rod shape fuel assembly of PWR and plate-type fuel assembly,respectively.The numerical results indicated that the calculated values of fuel assembly infinite multiplication factor k_∞ and main nuclides atom density by KYLIN-1 are in good agreement with those of other international organizations;relative power distribution of PWR fuel assembly is in good agreement with the referenced code.

Study on Heat Transfer Correlation in Supercritical Water through a Vertical Tube

Wen Qinglong, Wang Hongyang, Zhao Meng, Gu Hanyang, ChenG Xu

2017, 38(2): 15-18. doi: 10.13832/j.jnpe.2017.02.0015

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A semi-empirical heat transfer correlation is investigated based on the heat transfer experimental data.Calculations predicted by using literature and present correlations are evaluated and compared with the present experiments and literature experiments.Results show that the present correlation can well predict the heat transfer enhancement and heat transfer deterioration phenomenon,rather than the normal heat transfer of the supercritical water.

Analysis of Heat Transfer Coefficient on Natural Circulation of Supercritical Water Based on Grey Relational Model

Chen Juan, Ma Dongliang, Zhou Tao, Qi Shi, Xiao Zejun

2017, 38(2): 19-23. doi: 10.13832/j.jnpe.2017.02.0019

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In the case of severe accident evaluation,supercritical water-cooled reactors will take advantage of the natural circulation driving forces to carry the core waste heat in the cycle.But there are many factors influencing the supercritical water heat transfer coefficient.Quantitative determination of the influence of each factor on the heat transfer coefficient has certain practical reference value for improving the design of supercritical water-cooled reactor.Based on the experimental data of supercritical water in natural circulation,seven factors are selected to analysis the HTC（heat transfer coefficient） using the grey relational model.The factors include heating power,diameter,system pressure,inlet temperature,outlet temperature,wall outlet temperature and system circulation flow rate and so on.Through the analysis,we can get that the resolution has important effects on the grey relational model result.Through the analysis of the grey correlation degree about heat transfer coefficient,it can provide theoretical basis for the prediction of heat transfer coefficient.

Experimental Investigation on Heat Transfer of Supercritical Pressure Water Flowing in Sub-Channel with Triangle Distribution in Reactors

Xu Weihui, Ma Ziqiang, Wang Weishu, Cui Qiang, Zhu Xiaojing, Lu Tong, Bi Qincheng

2017, 38(2): 24-27. doi: 10.13832/j.jnpe.2017.02.0024

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Experimental investigation on the heat transfer and flow of supercritical pressure water flowing in the sub-channel of SCWR,which was simulated by a vertical triangular channel,was conducted at the pressures of 23~28 MPa,mass fluxes of 700~1300 kg/（m²·s） and heat fluxes on the inner wall surface of 200~800 kW/m².The corresponding diameter of the fuel rod is 8mm and the ratio of pitch to diameter is 1.4.The effects of heat flux,pressure and mass velocity on the heat transfer characteristics were analyzed.Experimental results showed that the wall temperature increases and the peak of heat transfer coefficient decreases with the increasing of the heat flux and pressure when other parameters remain unchanged.Improvement of mass velocity can enhance the heat transfer,which is characterized by the lower wall temperature and higher heat transfer coefficient.However the intensify effect of mass velocity on the heat transfer performance is not obvious when it reaches a certain level.The wall temperature varies dramatically with the increasing of the enthalpy and the peak heat transfer coefficient is much lower than that of the lower heat flux when the heat flux reaches 800 kW/m².And the enhanced heat transfer that usually appears in the large specific heat region is greatly weakened when the pressure rises up to 28 MPa.

Two-Phase Pressure Drop Characteristics in Circular Tube under Rolling Motion

Zhou Huihui, Xie Tianzhou, Xu Jianjun, Chen Bingde, Zhang Bin

2017, 38(2): 28-31. doi: 10.13832/j.jnpe.2017.02.0028

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Abstract:
An experimental study on the pressure drop in the circular tube was carried out under rolling condition,and the transient and time averaged data were obtained.The pressure drop calculation model under rolling condition was established and agreed well with the experimental data.The effect of rolling motion on the pressure drop characteristics was researched by analyzing the experimental and calculation results.It found that the cyclical fluctuation occurs in the transient total pressure drop,while the deviation of average total pressure drop is very small compared with static condition.By analyzing the transient total pressure drop and its composition,it is found that the friction pressure drop is almost constant under rolling condition;the additional pressure drop caused by rolling motion can be ignore;and the fluctuation of gravity pressure drop is the reason of total pressure drop fluctuation.

Research on Onset of Pressure Drop Oscillation Flow Instability in A Two-Phase Natural Circulation System

Peng Chuanxin, Chen Bingde, Zhuo Wenbin, Xu Jianjun, Huang Yanping, Zan Yuanfeng, Liu Wenxing

2017, 38(2): 32-37. doi: 10.13832/j.jnpe.2017.02.0032

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The onset of pressure drop oscillation in a two-phase natural circulation system was investigated in this paper.When the fully developed subcooling nucleate boiling happens in the test section,the fluctuating flow appears between the natural circulation loop and the pressurizer,which is caused by the generation of large amount of bubbles in the test section and the compressible space in the pressurizer.The fluctuating flow results in the occurrence of the pressure drop oscillation（PDO） in the natural circulation system.The power of the test section,when fully-developed sub-cooled nucleate boiling（FDB） occurred at the outlet,was calculated using both Bowring model and Saha-Zuber model.The calculated results are compared to the experimental power data at the onset of PDO.The error is less than 8 percent.Therefore the point of FDB can be considered to the onset of the PDO in the natural circulation system.

Investigation of Vibration Amplitude Effect on Local Flow Parameters of Two-Phase Flow

Xiao Xiu, Zhu Qingzi, Chen Shaowen, Zhang Yajun, JiA Haijun, Mamoru ishii

2017, 38(2): 38-42. doi: 10.13832/j.jnpe.2017.02.0038

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Abstract:
In order to investigate the vibration effect on local two-phase flow parameters,local measurements of two-phase flow parameters including void fraction,Sauter mean diameter and interfacial area concentration were conducted using conductivity probe under vibration condition.The experiment was firstly conducted under static condition.The vibration modes were then imposed on the test section through the rotation of eccentric cam on the top of the test section.The vibration period of the test section was kept at 0.5s and three vibration amplitudes,which were 4.8 mm,9.5 mm and 15.9 mm respectively,were adopted.The experiment results showed that the vibration had very limited effects on the time-averaged local parameters of the gas-water two-phase flow.But the additional inertial force induced by the vibration would significantly change the distribution of local two-phase flow parameters in the annulus and the variations of local flow parameters increased greatly with the vibration amplitude.For the flow condition with lower void fraction,the non-dimensional void fraction peak can reach up to 70% as the vibration amplitude increased to 15.9 mm,but the vibration effect decreased with the increasing of gas flux.

Experimental Study on Long-Time Cooling Characteristics of Passive Residual Heat Removal System

Zhou Huihui, PenG Chuanxin, Xu Jianjun, Li Yang

2017, 38(2): 43-45. doi: 10.13832/j.jnpe.2017.02.0043

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An experimental investigation on longtime cooling is carried out in a removal of all core power condition for understanding the running characteristics of ACP100 passive residual heat removal system（PRS）.The investigation finds a continuance of natural circulation,which is due to stored heat releasing from reactor,core and steam generator.The natural circuit flow of PRS keeps from 0.52 t/h to 0.26 t/h;meanwhile,the system pressure of PRS falls from 1.0 MPa to 0.51 MPa,and the outlet temperature of the reactor core falls from 178.1℃ to 105.0℃.Besides,the investigation shows that natural circulation is descending continuously,and never restarts after stagnation.

Effects of Nucleation Site Spacing on Bubble Merger Characteristics during Subcooled Boiling

Bi Jingliang, KE Daoyou, Xu Jianjun, Huang Yanping, Zan Yuanfeng

2017, 38(2): 46-50. doi: 10.13832/j.jnpe.2017.02.0046

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Subcooled boiling is an important phenomenon during the thermal hydraulics process in nuclear reactors.Bubble merger is a common form of bubble interactions.This paper studies bubble merger characteristics and heat flux distributions at various nucleation site spacing.A microheater array is used to control the nucleation site spacing and measure the heat fluxes in detail.A CCD camera measures the bubble dynamics from bottom view.The correlations of bubble dynamics and heat flux distributions under bubbles are analyzed and the effects of nucleation site spacing are summarized.

Experimental Study of Natural Circulation Flow Instability in Rectangle Channels

Chen Juan, Zhou Tao, Qi Shi, Ma Dongliang, Xiao Zejun

2017, 38(2): 51-55. doi: 10.13832/j.jnpe.2017.02.0051

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Results under different heating power conditions were conducted in rectangle channels with 5mm and 10 mm.Results for different heating powers were obtained.The results showed that the oscillation period of pressure value and volume flow are the same,but their phase positions are opposite.The existence of edge position and secondary flow will strengthen the disturbance of fluid flow in rectangle channels,which contributes to the heat transfer.The disturbance of bubble and fluid will be strengthened,especially in the saturated boiling section,which makes it possible for the mixing flow.The results also showed that the resistance in 5mm channel is bigger than that in 10 mm channel,and it is less likely to form stable natural circulation in the subcooled region.

Study on Control Requirements of Radioactive Pollution in Secondary Cycle of PWR Nuclear Power Plants

Liu Jie, Tang Shaohua, LÜ Weifeng

2017, 38(2): 56-59. doi: 10.13832/j.jnpe.2017.02.0056

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PWR nuclear power plant steam generator tube leak will result in radioactive contamination,affecting the release of radioactive effluent to the environment.It is necessary to set the leak rate monitoring system and steam generator blowdown system for controlling the secondary cycle system water quality and the radioactive environment release within an acceptable range.By analyzing the migration path of the radioactive secondary cycle,the calculation models of secondary cycle source term and radioactive effluent are obtained.According to the calculation models and assumptions of the secondary cycle radioactive control requirements,the steam generator tube leak rate at design basis is determined,and the design requirements on leak detection system and blowdown system of the steam generator are developed.

Test Research of Hydrogen Removal Characteristics of Passive Autocatalytic Hydrogen Recombiner in NPPs

Wang Hongqing, Li Zhiming, Li Yong, Ma Weigang, Jiang E, Wang Chun, Fu Shengwei

2017, 38(2): 60-63. doi: 10.13832/j.jnpe.2017.02.0060

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Passive autocatalytic hydrogen recombiners（PAR） are extensively used in the GRE-II,GRE-II+,and GRE-III NPPs.Based on the requirements for key parameters of PAR,such as working features,start and stop threshold,hydrogen removal ability and ignition threshold,the experiment apparatus is designed and constructed which can simulate the NPS severe accident condition and verify the PAR key characteristic parameters under passive condition.Test method is established,and series experiments on the start and stop threshold,starting time,hydrogen removal ability and ignition threshold were carried out.The test results show that different test conditions will lead to differences in PAR parameters,for that reason,only limited methods and conditions are suggested to use to get the unified,measurably quantified PAR key parameters.

Extension of Instrument Calibration Intervals Base on Improved AFAL Analysis

Chen Yun, Zhao Lihong, Yu Tao, He Lihua, Liu Zijing, Xie Jinsen

2017, 38(2): 64-67. doi: 10.13832/j.jnpe.2017.02.0064

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Base on the improvement of AFAL analysis,especially the improvement of the statistical analysis method,an improved model of AFAL analysis is proposed.The result of engineering example studies have shown that,the proposed method is effective and perfect,and it can visually describe the characteristics of instrument drift,and is much better to prove the stability of extended instrument calibration cycle.

Preparation of Rescue Coordination Program for Major Nuclear Accident Emergency in Liaoning Hongyanhe Nuclear Power Plant

Li Qi, SuN Mingjun, Wu Wei, Du Haidong

2017, 38(2): 68-71. doi: 10.13832/j.jnpe.2017.02.0068

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This paper introduces the preparation requirement and main content of Rescue Coordination Program for Major Nuclear Accident Emergency in Liaoning Hongyanhe Nuclear Power Plant and analyzes the site emergency support needs.Results include the overall plan for national nuclear emergency rescue forces to participate in the nuclear emergency rescue compiled by the National Nuclear Emergency Office,the Hongyanhe site emergency coordination plan compiled by Hongyanhe Nuclear Power Plant and the nuclear emergency rescue plan of Hongyanhe nuclear power plant supported by XX compiled by the national nuclear radiation pollution emergency disposal team.The nuclear emergency coordination program for Hongyanhe Nuclear Power Plant establishes the vertical nuclear emergency support system consisted of the state,the military,the local governments and the nuclear power plant,which can precisely provide the support and avoid the isolation in the response to the major nuclear accidents.

Methodological Study on Prediction of Detonation Cell Width with Gaussian Process Regression

Hou Bingxu, Yu Jiyang, Xu Zhanjie, Jiang Guangming, Zou Zhiqiang

2017, 38(2): 72-77. doi: 10.13832/j.jnpe.2017.02.0072

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Detonation cell width is an important parameter to quantify the detonation risk of a flammable gas mixture.In this study,detonation cell width,λ,is correlated with the characteristic chemical reaction zone width,δ.Regression is performed by using experimental data,with non-dimensional activation energy and non-dimensional temperature as independent variables and the logarithm of λ/δ as a dependent variable.Considering the disadvantages of traditional parametric regression methods,a Gaussian process regression based on machine learning,is applied in this study to fit the experimental data.By the comparison of the measured data and predictions of the regression result,it is found that the Gaussian process regression method can precisely predict the detonation cell width of flammable gas mixtures with different compositions and at different initial conditions.Meanwhile,the Gaussian process regression method takes an advantage in fitting precision comparing to the traditional parametric regression methods.

Effect of Zinc on Stress Corrosion Crack Growth Rate of Type 316 Stainless Steel

Du Donghai, Chen Kai, Zhang Lefu, Shi Xiuqiang, YiN Kaiju

2017, 38(2): 78-83. doi: 10.13832/j.jnpe.2017.02.0078

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The effect of zinc（10,20,40 μg/kg） on stress corrosion cracking of 316 stainless steel was studied in this work by using the direct current potential drop method to measure the crack growth rate in high temperature water.The experiment results show that the crack growth decreases by 5 times after addition of 10 μg/kg zinc,however the crack growth rate slightly increased after adding 20,40 μg/kg of zinc.

Effect of Different pH Value Potassium Permanganate Solution on Corrosion Property of Stainless Steel

Song Lijun, Li Xinmin, Liu Bin, Xie Jianli

2017, 38(2): 84-87. doi: 10.13832/j.jnpe.2017.02.0084

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Corrosion behaviors of 304 L stainless steel in different pH value potassium permanganate solution were investigated using the gravimetric analysis method,scanning electron microscope（SEM）,potentiodynamic polarization.Most of the corrosion products are on the surface of 304 L stainless steel exposed in acid potassium permanganate（NP,pH=1.8）.A minimum of corrosion products are on the surface of 304 L stainless steel exposed in potassium permanganate（HP,pH=6.5）.Corrosion products on the surface of 304 L stainless steel exposed in alkalinity potassium permanganate（AP,pH=12.5） are in middle.All specimens through reduction cleaning process of nitric acid and ascorbic acid show metallic luster.And there is no obviously effect on micromorphology of 304 L stainless steel exposed in NP,HP and AP solution.The corrosion density ic of 304 L stainless steel in HP solution is less than that in NP and AP solution.The results have showed that the corrosion ability of NP and AP solution for 304 L stainless steel is more vigorous than that of HP solution in the chemical decontamination process.

Microstructure Evolution in Hydrogenation and Dehydrogenation Process of Zircaloy

Lan Guangyou, Tang Bin, Pu Yongxing, HE Zujuan, Liu Siwei, Yuan Zhengchuan, Hu Rui

2017, 38(2): 88-92. doi: 10.13832/j.jnpe.2017.02.0088

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The phase compositions of zircaloy changing in hydrogenation and dehydrogenation process were analyzed by XRD.The microstructure was observed by metallographic.The results show that the phase compositions of zircaloy changing in the two process are same.The microstructures changing in the two process is only different in α+δ+γ three phase zone.The network-like distribution phase changing in the hydrogenation progress is more significant than that in the dehydrogenation process.In the rest phase zone,the hydrogen content determines the microstructures of zirconium hydride.The main reason for this phenomenon is that the hydrogen diffusion mode in the hydrogenation is different to that in the dehydrogenation process.The hydrogen diffusion in the hydrogenation progress is controlled by the grain boundary diffusion,and the hydrogen diffusion in the dehydrogenation progress is controlled by the crystal diffusion.

Study of Hydrogen Permeation and Diffusion in 690 Alloy

Wang Chun, Wang Yongli, Fu Shengwei, Xiong Liangyin, Zhang Junping, Liu Shi

2017, 38(2): 93-97. doi: 10.13832/j.jnpe.2017.02.0093

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The diffusivity and permeability of hydrogen in Inconel 690 alloy were investigated using an ultra-high vacuum gaseous permeation technique.The curves of hydrogen permeation of 690 alloy materials with different thickness over the temperature range of 300~500℃ were gained,and the effects of thickness of 690 alloy on the hydrogen diffusivity（D） and permeability（P） were discussed.The results indicated that the diffusivity and permeability of hydrogen with the change of temperature in Inconel 690 alloy were conformed to Arrhenius relationship in the extent experimental temperature range.The hydrogen diffusivity increased with the increasing of samples thickness and equal to the actual body diffusivity of Inconel 690 alloy,and the hydrogen permeability kept constant with the increasing of sample thickness.

Analysis and Evaluation of Corrosion Resistant Alloy by Low Temperature Surface Treatment Technology

Zhang Xiangfeng, Gong Daitao, Wang Jun, Qiu Shaoyu, Li Cong, Dong Hanshan

2017, 38(2): 98-102. doi: 10.13832/j.jnpe.2017.02.0098

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Special environment requires the parts in the core of water-cooling nuclear power reactors to have good corrosion resistance and high surface wear resistance.Stainless steel and nickel base alloys have good corrosion resistance but their hardness and wear resistance are low.This technical challenge can be addressed by low temperature nitriding or carburizing to produce carbon and/or nitrogen supersaturated expanded austenite（i.e.S-phase） with high hardness,high wear resistance and good corrosion resistance.This paper mainly overviews the development,the microstructure,the unique combination of attractive properties and the application prospect of low temperature S-phase surface treatment of stainless steel using gas,plasma and salt bath mediums.The microstructure,hardness,wear resistance and corrosion resistance of S-phase are analyzed and evaluated.

Simulation and Analysis of Single Control Rod Dropping Behavior Based on Dynamic Grid Technique

Xiao Cong, LuO Ying, Du Hua, Wang Liubing

2017, 38(2): 103-107. doi: 10.13832/j.jnpe.2017.02.0103

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A smart nuclear reactor control rod drive line was used as the research object,and a 3-D fluid simulation model of single control rod dropping was set up.Velocity and pressure nephogram in the guide tube were obtained by simulating the control rod dropping behavior based on dynamic grid technique,and the displacement cure,velocity cure and pressure cure were obtained as well.Comparison of the simulation and experiment results showed that the simulation results were in good agreement with the experimental results.Some important parameters can be calculated by this method,such as the time of control rod dropping process and the maximum impact force,so it can provide references for the design of control rod drive line structure.

Research on Rod Drop of Control Rod Drive Line under Vertical Seismic Load

Li Pengzhou, Du Jianyong, Li Tianyong, Sun Lei, Li Qi

2017, 38(2): 108-110. doi: 10.13832/j.jnpe.2017.02.0108

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To verify the safety of the reactor,the limit of rod drop time for control rod drive line（CRDL） shall be set in the design of reactor.Only horizontal seismic load was considered in the seismic test and rod drop analysis research at present.In this paper analysis and test research on the effect of the rod drop under the vertical seismic load was conducted.The result shows that the vertical seismic load added the complexity of the rod drop,and the vertical seismic load would cause obvious effect on the rod drop time of the control rod.

Dynamic Finite Element Analysis Methods for Liquid Container Considering Fluid-Structure Interaction

Bao Xin, Liu Jingbo

2017, 38(2): 111-114. doi: 10.13832/j.jnpe.2017.02.0111

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In this paper,calculation results from Fluid-Structure-Interaction Finite Element Method（FSI-FEM） and the theoretical solution are examined on the cylindrical liquid container case.The applicability of FSI-FEM is discussed.Results show that FSI-FEM is able to calculate the vibration characteristics and dynamic response of the liquid container accurately.This method can further be employed in predicting the dynamic characteristics and analyzing the seismic time history of complex FSI models.

Drain Method for Spent Resin Transportation Penetration in AP1000 Local Leak Rate Test

Liu Chi, Qiu Fengxiang

2017, 38(2): 115-117. doi: 10.13832/j.jnpe.2017.02.0115

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It is necessary to drain and blow down for the penetration of Chemical and Volume Control System before containment local leak rate test in AP1000 Nuclear Power Plant.However,there is no drain valve in the lowest position because high radioactivity exists in operation condition.Normal drain methodology cannot be applied to this penetration.Based on practices in a nuclear power plant,advantages and disadvantages for different methods are analyzed and compared in this paper.Finally,three-step solution is used to drain:firstly drain by gravity,secondly suck water by vacuum pump and then blow down by compressed air.Using this method,the drain puzzle is handled safely and properly.Local leak rate test is performed successfully.

IER-ICP-OES Measurement Study of Lithium in Primary Circuit Water Containing Boric Acid in Nuclear Power Plants

Lin Qinghu, Xu Tianfeng

2017, 38(2): 118-121. doi: 10.13832/j.jnpe.2017.02.0118

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In pressurized water reactor nuclear power plants,the primary circuit control uses theboron-lithium coordination solution.Under the existence of the boric acid in the primary circuit water,boric acid easily crystallize in the atomization system of inductively coupled plasma optical emission spectrometer,which affect the determination of the lithium ion concentration.In this study,ion exchange resin-inductively coupled plasma optical emission spectrometer online combination analysis system was developed,which used allochroic ion exchange resin to remove the boric acid of the primary circuit water.Under the optimized conditions with the detection wavelength of 610.362 nm and 670.784 nm,the recovery of standard addition and relative standard deviations are 98.4% and 101.9%,and the relative standard deviation is 0.97% and 0.42%（n=6）.The system has the advantage of simple structure,low cost,ease of building without the requirement of complexly fabricated devices,convenient operation,and completely removed boric acid.

Maintenance Accessibility for Key Equipments in Integrated Small Pressurized Water Reactors

Chen Wen, Jiang Hong, YiN Qin

2017, 38(2): 122-125. doi: 10.13832/j.jnpe.2017.02.0122

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Integrated small pressurized water reactors are with compact layout of equipment and with narrow space,and its maintenance accessibility has always been a challenge in the design and operation period.But there is no qualitative method for the effective evaluation of the maintenance accessibility.Products with good maintainability not only ensure the reliability,but also ensure the minimum maintenance required resources（such as time,manpower,material and costs）,and thus ensure the optimized maintenance economy under the premise of safe maintenance.Based on the design features of the integrated small pressurized water reactors,this paper analyzes the key equipment maintenance requirements,and presents the maintenance accessibility evaluation index.

Technical Analysis of Resin Unit in PWR NPPs

Lu Tiezhong, Chen Liang, Wu Xuesong

2017, 38(2): 126-129. doi: 10.13832/j.jnpe.2017.02.0126

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The composition and function as well as operation of the resin system in primary coolant and nuclear auxiliary system in domestic M310 unit were introduced.The technical analysis of the resin system was made in terms of chemistry,process,operation,maintenance as well as waste production.The relevant proposal was also given in this paper.It can offer a reference for the design and update of analogue systems.

Fault Handling of Nuclear Power Plant PLC Data Acquisition System Based on MSG Instruction

Li Guangfeng, Li Shi, Zhang Mingliang

2017, 38(2): 130-133. doi: 10.13832/j.jnpe.2017.02.0130

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Ling’ao Nuclear Power Station data acquisition system is responsible for the analog and digital data acquisition for the whole plant equipment.There has been sporadic offline fault of data acquisition board and a fault condition PLC acquisition can not be automatically reset.Because the system’s PLC program and PC with an integrated design,modifying PLC program alone is impossible.Through the use of an external PLC device MSG instruction and the MSG instruction reset remotely by means of a process to achieve the offline PLC Fault,solved the problem that original system LEVEL1 layer PLC program can not be modified.

Research on Setpoints in Operation Procedures of Nuclear Power Plants

SHi Jin

2017, 38(2): 134-139. doi: 10.13832/j.jnpe.2017.02.0134

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Operation procedures of nuclear power plants are closely related to the operation safety of nuclear power plants.The setpoints information is an important part of operation procedure contents,and the setpoints determination is very difficult in operation procedure development.The operation procedure system and setpoint contents are analyzed for advanced passive plant of demonstration project,and the functions and the structures of setpoints are also analyzed following the requirement of nuclear safety regulations.A systematical approach is provided for setpoints determination,and it is meaningful for the independent operation procedure development of advanced passive plants,as well as the operation safety of plants.

Management and Prevention of Low Bearing Insulation for Reactor Coolant Pump Motors of CPR1000 Nuclear Power Plant

Duan Shengzhi, Li Qiangtao, SHi Shengli, Lu Hongjie, Li Gengliang

2017, 38(2): 140-144. doi: 10.13832/j.jnpe.2017.02.0140

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Considering the incident of bearing insulation lost for reactor coolant pump motor in Unit 3 of CPR1000 Ningde Nuclear Power Plant,three main reasons for low bearing insulation of the reactor coolant pump motors are analyzed and studied.14 standard check-up steps are formed to solve the low bearing insulation for reactor coolant pump motors successfully.Five measures to prevent the motor from low bearing insulation on site are proposed.

Optimization Research of Elbow Flow Meter Design with Alterable Measurement Range

Zhang Lin, Wu Xiaofei, Li Minggang, Rong Xiaohong, Wang Yunsheng

2017, 38(2): 145-148. doi: 10.13832/j.jnpe.2017.02.0145

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In this paper,the design concept of two elbow flowmeters with alterable measurement range is studied by CFX numerical simulation.The results show that:a.changing the pressure taps of the traditional elbow flow meter could not significantly increase the differential pressure under the low flow condition;b.Throttling elements could increase the differential pressure;c.The airfoil could make the differential pressure increase 25%.

Mechanical and Critical Study of a New Fuel Assembly Container

Wu Chunhu, Wu Guangming, Xiang Jiawei, Cai Guichuan

2017, 38(2): 149-155. doi: 10.13832/j.jnpe.2017.02.0149

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The mechanical and critical calculation methods used in the design process of a new fuel container were introduced in this paper.Based on the design laws and regulations,the mechanical simulation was carried out,which including stacking performance computing in the limiting condition,modal analysis and fatigue failure calculation under the road transportation.At last,the single and array critical calculation of the new design container in different work conditions were carried out.The results mentioned above offered references for the container detailed design.

Research of Deposit Characteristics on Sludge Collector for Steam Generator

Li Yang, Cao Nian, Lin Xinru, Niu Maozhi, Zhou Huihui, Huang Zhigang, Huang Jun, Zan Yuanfeng, Yang Zumao

2017, 38(2): 156-160. doi: 10.13832/j.jnpe.2017.02.0156

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Numerical simulation was used to study the flow field characteristics of sludge collector and the effects of key factors on the collection performance.Studies have shown that the effects of different cutting modes on the flow field characteristics of sludge collector could be ignored.With the particle concentration increased,the amount of single mass collection increased,but the single collection efficiency unchanged.Under the condition of the same inlet and outlet of sludge collector,with the particle diameter increased,the collection capability of sludge collector increased.There was an optimum inlet and outlet aperture of sludge collector in each particle diameter.

Study on Instantaneous Risk Calculation in Real-Time Online Risk Monitor

Wang Yan, Zhang Zhijian, Zhang Min, Zhang Huazhi, Ma Yingfei

2017, 38(2): 161-164. doi: 10.13832/j.jnpe.2017.02.0161

Abstract(13) PDF(0)

Abstract:
In the exiting risk monitor,the configuration information of specified plant is obtained by manual input.The historical running status and corresponding times of the devices cannot be put into risk monitor.In the Real-Time On-Line Risk Monitor（RORM） the running status and time of the components are collected and stored by automatic mode and manual mode.The historical running status and time from start to failure are considered in the cumulative failure probability of specified successive operating device.For example,two parallel pumps in a system experience the operation,hot reserve and then operation.The cumulative failure distribution functions of running failure basic event of two pumps are given.The functions show the instantaneous risk is related to the historical running status and time.The instantaneous risk curve shows an increasing trend with the time.

Calculation Method of Flange for RCC-M

Zhao Wei

2017, 38(2): 165-168. doi: 10.13832/j.jnpe.2017.02.0165

Abstract(11) PDF(0)

Abstract:
Taking the accumulator and filter in Taishan Nuclear Power Station as an example,the flange joint calculation method under pressure,temperature,external force and moment is introduced in detail in terms of operation condition,transient analysis and calculation model disposal.It especially considered that the flange and stud integrality may be affected at the transient when the temperature increases greatly,and the flange seal could be affected when the flange dish declining angle is too big resulting from the over tightened stud.The flange design calculation can be referenced in other engineer projects.

Analysis of Empirical Pressure Drop Correlations and CFD Numerical Study on Spacer Grid

Han Bin, Yang Baowen, Zhang Hui, ChA Yudong, Peng Cheng

2017, 38(2): 169-174. doi: 10.13832/j.jnpe.2017.02.0169

Abstract(15) PDF(0)

Abstract:
Estimating pressure drop accurately is the key to develop and design spacer grids.Grid pressure drop prediction models are reviewed.Most of the empirical corrections applied for the pressure drop calculations do not contain any real geometrical parameter to characterize the grid effect.From the aspect of fundamental research,the influence of the dimple location,distance of the mixing vane to the nearest strip and the effect of inter-subchannel mixing among neighboring subchannels on pressure drop and downstream flow fields are analyzed using the commercial CFD codes.Based on this study,it is concluded that more detailed geometry parameters of spacer grid should be added into the correlation when predicting the pressure drop.Dimple location,configuration of mixing vanes and grid strip opening should be optimized for different design targets and functions when developing spacer grids.

Prediction Model of Boiling Heat Transfer Coefficient in Rectangular Narrow Channel

Chen Chong, Meng Qingzheng, Wu Wei, Liu Dongmin, Gao Puzhen

2017, 38(2): 175-178. doi: 10.13832/j.jnpe.2017.02.0175

Abstract(13) PDF(0)

Abstract:
Flow boiling heat transfer experiments were performed in a rectangular narrow channel,and a new correlation was developed for predicting the boiling heat transfer coefficient.Different models for flow boiling heat transfer were used to predict the boiling heat transfer and the values were compared against the experimental database.The results show that Chen correlation and Lazarek-Black correlation could not well predict the boiling heat transfer coefficient of the rectangular narrow channel,and the Kim and Mudawar correlation is the best method among the models.A new correlation is developed based on the Schrock-Grossman model and the mechanism of forced convection boiling heat transfer.The correlation can well predict the boiling heat transfer coefficient.

Pool Boiling Heat Transfer on Multi-Scale Porous Surfaces

Zheng Xiaohuan, Ji Xianbing, Wang Ye, Xu Jinliang, Huang Yanping, Li Yong

2017, 38(2): 179-183. doi: 10.13832/j.jnpe.2017.02.0179

Abstract(18) PDF(0)

Abstract:
In order to improve the nuclear boiling heat transfer,a multi-scale porous surface was prepared by sintering the copper particles.A series of pool boiling experiments on different heater surfaces were conducted using deionized water as working fluid at atmospheric pressure.The effects of surface structure,liquid temperature,heat flux and surface superheat on the pool boiling heat transfer were investigated.The results showed that the multi-scale surface can perfectly meet the different demands for pore size between vapor release and liquid suction.For multi-scale surface,The surface superheat at the onset of nuclear boiling was decreased significantly and heat flux was expanded.Compared to that of a plain surface,the boiling heat transfer coefficient can be improved 5 to 6 times.

Predictive Study of Bubble Mean Diameter in Subcooled Flow Boiling

Hong Gang, Xu Zhigang, Bian Boshen, Zhang Yaoli, Yan Xiao, Huang Yanping

2017, 38(2): 184-188. doi: 10.13832/j.jnpe.2017.02.0184

Abstract(11) PDF(0)

Abstract:
Bubble mean diameter is a key parameter to calculate the interfacial transfer equation of two phase flow and interfacial concentration.Taking into account the effects of both the thermal,hydrodynamic conditions and bubble coalescence rate on the mean bubble size in the channel,a model has been developed.The proposed model agreed well with the experimental data within the averaged relative deviation of ±12.5%.

2017 Vol. 38, No. 2