核动力工程

Analytic Function Expansion Nodal Method for Hexagonal Geometry Corrected by Discontinuity Factors

NI Dong-yang, XIAN Chun-yu

2010, 31(2): 1-5.

Abstract(9)

Abstract:
Analytic function expansion nodal method for hexagonal geometry is improved,by introducing the discontinuity factors based on the analytic function expansion nodal method,and the programs FEMHEX-DF and FEMHEX-DFH have been developed.This paper has calculated two benchmark problems with UO₂ and MOX fuel assemblies by these programs,and the numerical results confirm that the improved method can increase the computational accuracy of the core power distributions and keff effectively,especially to the heterogeneous core.

Verification and Validation of Multi-Group Library MUSE1.0 Created from ENDF/B-VII.0

CHEN Yixue, CHEN Chaobin, WU Jun, YANG Shouhai, ZHANG Bin, LU Daogang

2010, 31(2): 6-10,15.

Abstract(13)

Abstract:
A multi-group library set named MUSE1.0 with 172-neutron group and 42-photon group is produced based on ENDF/B-VII.0 using NJOY code.Weight function of the multi-group library set is taken from the Vitanim-e library and the max legendre order of scattering matrix is six.All the nuclides have thermal scattering data created using free-gas scattering law and 10 Bondarenko background cross sections se lected to generate the self-shielded multi-group cross sections.The final libraries have GENDF-format,MATXS-format and ACE-multi-group sub-libraries and each sub-library generated under 4 temperatures（293 K,600 K,800 K and 900 K）.This paper provides a summary of the procedure to produce the library set and a detail description of the validation of the multi-group library set by several critical benchmark devices and shielding benchmark devices using MCNP code.The ability to handle the thermal neutron transport and resonance self-shielding problems are investigated specially.In the end,we draw the conclusion that the multi-group libraries produced is credible and can be used in the R＆D process of Supercritical Water Reactor.Design.

Three Dimension Neutron Transport Characteristics Method Code（Ⅰ）——Interpolation Treatment of Boundary Condition

CHAI Xiaoming, YAO Dong, WANG Kan

2010, 31(2): 11-15.

Abstract(8)

Abstract:
Spatial and angular problems exist when Method of Characteristics（MOC） treats the reflective boundary condition in 3-D neutron transport problems.Spatial interpolation method and angular interpolation method are proposed to solve the spatial problem and the angular problem respectively.There is no restriction on the choice of angular product quadrature set and ray trajectories layout,when using the interpolation method to treat the reflective boundary condition.

Three Dimension Neutron Transport Characteristics Method Code（Ⅱ）——Numerical Verification

CHAI Xiaoming, YAO Dong, WANG Kan

2010, 31(2): 16-20.

Abstract(10)

Abstract:
Three dimensional characteristics method code TCM is introduced and verified in this paper.And the influence of boundary interpolation,quadrature set and mesh size on accuracy of results are given.It is shown that TCM,using interpolation treatment of boundary condition,can calculate the neutron transport problems accurately,of which geometry and reflective boundary are arbitrary.

Strategy for Steam Generator Tube Rupture Accident with Total Loss of Pressurizer Spray

LU Xianghui, JIANG Xiaohua, WANG Ting, OUYANG Yong

2010, 31(2): 21-23,28.

Abstract(7)

Abstract:
Typical cases of SGTR accident under total loss of pressurizer spray with or without application of the strategy are analyzed using CATHARE code,and the accident scenario and results are discussed in detail.In addition some sensitivity study on number of ruptured tubes and initial power level are done and finally the possible negative effects are discussed.The analyses demonstrate that the strategy of pressurizer relief proposed by the document can significantly reduce the contaminated water and steam release to environment for SGTR accident under total loss of pressurizer spray,and the negative effect can be neglected.

Criticality Calculations of Burnup-Credit Spent Fuel Storage Pool for Nuclear Power Plants

ZHANG Puzhong, CHEN Yixue, MA Xubo, MAO Yayu, SHI Shengchun, ZHANG Bin

2010, 31(2): 24-28.

Abstract(8)

Abstract:
In order to study the spent fuel dense storage feasibility of a new type of fuel assembly with 4.95% enrichment,taking the spent fuel storage pool of Ling’ao Nuclear Power Station Units 3 ＆ 4 as calculation model,and using the burnup-credit analysis sequence STARBUCS in SCALE5.1 code system,this paper analyzes the yield changes of actinium nuclides and fission products in different burnup conditions as well as its effect on reactivity.Also,based on full burnup credit level,this paper shows the calculation for the critical security of the pool in different burnup levels and storage periods,and also shows the loading curve for spent fuel storage pool region II.The calculation result indicates that this new type of fuel assembly can be densely stored in the spent fuel storage pool region II when its burnup can reach 45GWd.t^-1（U）.

Failure Analysis of Cold Neutron Source In-Pile Parts

TANG Fengping, HU Chunming

2010, 31(2): 29-32.

Abstract(9)

Abstract:
A newly constructed CNS facility at a research reactor adopts liquid hydrogen as moderator.Because the CNS facility in-pile parts was installed in reflector vessel,which is very closed to reactor core,the safety of CNS facility especially the in-pile parts is very important to the reactor.This paper analyzes the status of CNS in-pile parts in various conditions（including failure） and the accident consequences.The results show that the failure of the in-pile parts is limited to the CNS facility,which has no effect on the reactor safety.

Pipe Deformation and Dynamic Stress Analysis During Water Hammer

CAO Yuan, JIN Xianlong, DU Xinguang

2010, 31(2): 33-36,42.

Abstract(19)

Abstract:
The finite element analysis（FEA） based on fluid-structure interaction（FSI） is applied in simulating the three-dimensional water hammer in the pipe.The FSI is achieved through the Arbitrary Lagrangian Eulerian（ALE） method.The results of finite element model are consistent with that of one-dimensional classical model.The model and method used in this research are confirmed.The maximum breathing deformation and the dynamic stresses in pipe wall are created at a significant time after the wave front has passed.The maximum deformation does not occur at either the wave front,or near the fixed ends of the pipe,but occurs about one-third of a pipe diameter away from the end.Among the dynamic stresses in pipe wall,the hoop stress is dominant in the effective stress and has the same period with water pressure wave.Finally,the simulation and analysis carried in this paper show the correctness and the affectivity of the proposed method.

Inlet Flow Analysis in Magnetic-Drive Condenser Pump Based on Numerical Simulation of Flow Field

KONG Fanyu, ZHANG Hongli, GAO Cuilan, XUE Kuanrong

2010, 31(2): 37-42.

Abstract(10)

Abstract:
Variable-pitch inducers can be mounted before the impeller inlet to improve the anti-cavitation properties of magnetic-drive condenser pump.The fluid field of two magnetic-drive condenser pump models,which with and without the variable-pitch inducer before the impeller inlet,was numerically simulated by Fluent program,and the distribution of pressure was taken out and the trace of the particle was plot.The main characteristics of the interior fluid field were described by comparing with two groups of data.The results of numerical simulation show that the pump with the variable-pitch inducer can improve the anti-cavitation performance.

Research on Coupling of COBRA-IV and CFX

LIU Yu, ZHANG Hong, JIA Baoshan

2010, 31(2): 43-46.

Abstract(9)

Abstract:
Based on the study of the internal structure of subchannel code COBRA-IV and computa-tional fluid dynamics code CFX,the coupling interfaces have been developed,and an external control code was built to realize coupling of two codes.Results from the coupling calculation of a 5×5 rods assembly problem verified the COBRA-IV/CFX coupling code.

Transient Thermal-Hydraulic Characteristics Analysis Software for PWR Nuclear Power Systems

WU Yingwei, ZHUANG Chengjun, SU Guanghui, QIU Suizheng

2010, 31(2): 47-49,62.

Abstract(9)

Abstract:
A point reactor neutron kinetics model,a two-phase drift-flow U-tube steam generator model,an advanced non-equilibrium three regions pressurizer model,and a passive emergency core decay heat-removed system model are adopted in the paper to develop the computerized analysis code for PWR transient thermal-hydraulic characteristics,by Compaq Visual Fortran 6.0 language.Visual input,real-time processing and dynamic visualization output are achieved by Microsoft Visual Studio.NET language.The reliability verification of the soft has been conducted by RELAP 5,and the verification results show that the software is with high calculation precision,high calculation speed,modern interface,luxuriant functions and strong operability.The software was applied to calculate the transient accident conditions for QSNP,and the analysis results are significant to the practical engineering applications.

Mathematic Model for Nuclear Power Station with Integrated Secondary-Loop

XU Shijie, LIN Meng, YANG Yanhua, CHENG Xu

2010, 31(2): 50-53.

Abstract(12)

Abstract:
This paper models the thermal-hydraulic and control systems of nuclear and conventional islands of Ling’ao PhaseⅡ 1000 MW Nuclear Power Station by using RELAP5,and analyzes the turbine load from 100%FP（Rated power） step transient to 90%FP and then from 90%FP step transient to 100%FP.In the simulation of the transient process,the superiority of the integrated secondary-loop model in the analysis of turbine load step transient changes has been indicated.

Reliability Data Process and Analysis of Instrument and Control Switch in Nuclear Power Plants

SHI Jie, CHEN Denghua, SHI Haining, TU Fengsheng

2010, 31(2): 54-57,66.

Abstract(9)

Abstract:
Based on the actual failure data,the reliability analysis of Instrument and Control switch,by means of Exponential and Weibull distribution,are given in this paper.For zero-failure data,the Bayesian statistical theory was used.Failure of switches with various lifetime distributions was obtained.The methods were tested on three kinds of switches which were used in Daya Bay Nuclear Power Plant and the results indicated its validity.

Digitization and Simulation Realization of Full Range Control System for Steam Generator Water Level

QIAN Hong, YE Jianhua, QIAN Fei, LI Chao

2010, 31(2): 58-62.

Abstract(6)

Abstract:
In this paper,a full range digital control system for the steam generator water level is designed by a control scheme of single element control and three-element cascade feed-forward control,and the method to use the software module configuration is proposed to realize the water level control strategy.This control strategy is then applied in the operation of the nuclear power simulation machine.The simulation result curves indicate that the steam generator water level maintains constant at the stable operation condition,and when the load changes,the water level changes but finally maintains the constant.

Design of Parameter Polling Instrument for Fast Neutron Criticality Facility

HU Qian, LI Meng, HU Jinquan

2010, 31(2): 63-66.

Abstract(7)

Abstract:
In order to satisfy the requirement on the measurement and control system of the fast neutron criticality facility,the parameter polling instrument for the fast neutron criticality facility is designed for the real-time monitoring of the operation of the monitoring device,by integrating the intelligentized instrument with the virtual instrument technology.The configuration and design of the instrument is introduced in this paper.Experiment results show that the interference immunity,consistency,maintainability of the parameter polling instrument has been improved and satisfies the expected requirements.

Method of Dynamic Fuzzy Symptom Vector in Intelligent Diagnosis

SUN Hongyan, JIANG Xuefeng

2010, 31(2): 67-70.

Abstract(12)

Abstract:
Aiming at the requirement of diagnostic symptom real-time updating brought from diagnostic knowledge accumulation and great gap in unit and value of diagnostic symptom in multi parameters intelligent diagnosis,the method of dynamic fuzzy symptom vector is proposed.The concept of dynamic fuzzy symptom vector is defined.Ontology is used to specify the vector elements,and the vector transmission method based on ontology is built.The changing law of symptom value is analyzed and fuzzy normalization method based on fuzzy membership functions is built.An instance proved method of dynamic fussy symptom vector is efficient to solve the problems of symptom updating and unify of symptom value and unit.

Research on Condition Monitoring Method for Operator Support System

WANG He, CHENG Shouyu, ZHANG Zhijian

2010, 31(2): 71-75.

Abstract(11)

Abstract:
According to the technical requirements of the condition monitoring in Operator Support System（OSS）,the monitoring of plant condition and system status has been achieved.The finite state machine monitoring methods,threshold checking method and the trend monitoring methods were used in order to achieve the comprehensive operation support functions.The condition monitoring module was developed;and its functional testing was also done in a real-time full-scope simulator.The results revealed that the condition monitoring method is reliable and the module is capable of meeting the functional requirements of OSS.

Analysis of Fire Frequency in Nuclear Power Plants

HU Xiaomin

2010, 31(2): 76-80.

Abstract(20)

Abstract:
Based on the study on Fire Probabilistic Safety Assessment（PSA） Methodology for Nuclear Power Facilities reported by NRC and EPRI,the methodology for estimating the fire frequencies resulting from various fire sources during the process of fire PSA is introduced,and an example is demonstrated by estimating the fire frequencies of the main transformer in Daya Bay nuclear power plant,which shows its fire frequency is 4.32×10^-3 per RY and this is 203 times of the core damage frequency of the reactor.It also shows that once a fire occurred on the transformer,the probability of catastrophic result would be 83%.

Simulation of Oxidation in HTR-10 Core

YU Xinli, LUO Xiaowei, YU Suyuan

2010, 31(2): 81-84,97.

Abstract(7)

Abstract:
The oxidation behavior of graphite matrix in fuel element was investigated based on the reasonable simplification to the HTR-10 core.The gasification by steam and the combined effect by steam and oxygen were studied independently.The results showed that the gasification of fuel graphite matrix by steam was uniform and mainly occurred at the bottom where the temperature was high in the mean residency time of fuel element,while the corrosion by oxygen and steam was violent and the surface of graphite matrix was removed.

Oxidation Kinetics of N18 Zirconium Alloy at Temperatures of 600～1200℃ in Steam

LIU Yanzhang, QIU Jun, LIU Xin, ZHAO Wenjin

2010, 31(2): 85-88.

Abstract(10)

Abstract:
The oxidation kinetics of N18 alloy at the temperatures of 600℃～1200℃ in steam were investigated.The results showed that the oxidation kinetics was changed by varying the oxidation temperatures due to the phase transformations of the base metal and its oxide;parabolic rate（600℃～700℃） → parabolic-linear rate（800℃） →cubic rate（950℃） →cubic（or parabolic） linear rate（1050℃） →parabolic rate（1100℃～-1200 ℃）parabolic rate（at 1100℃～1200℃）.And the oxidation resistance of the N18 alloy at all the temperatures was superior to that of Zircaloy-4 from the higher rate exponent due to the Nb addition.

Study on Sorption Capacity and Characterization of Sr²⁺ on Synthetic Zeolite

WANG Jinming, YI Facheng

2010, 31(2): 89-93.

Abstract(8)

Abstract:
Sr²⁺ adsorption capacity of synthetic zeolite（ZF） are studied with the intermittence method,and ZF adsorbed the Sr²⁺ is characterized and analyzed by XRD,as a reference for the evaluation of the disposal effectiveness of low and medium radwastes.The results show that Sr²⁺ adsorption capacity of ZF is good,and the equilibrium time for ZF to adsorb Sr²⁺ is in range of 5～14 days.Sr²⁺ concentration has the greatest effect on ZF adsorption capacity,and the medium,temperature and pH value of the solution also have effect on ZF adsorption capacity.With the augment of Sr²⁺ concentration,the Sr²⁺ equilibrium adsorption quantity of ZF increases,but the equilibrium adsorption rate and equilibrium adsorption ratio decreases.Sr²⁺ adsorption capacity of ZF improves with the augment of pH value.Sr²⁺ adsorption capacity of ZF is complicate and varies with the different ion,concentration and other components in the medium solution.Sr²⁺ adsorption capacity of ZF increases with the augment of temperature.As a whole,when Sr²⁺ concentration in the solution is 0.005mol/L,the pH value of the solution,and the temperature of medium and solution have less effect on the Sr²⁺ adsorption capacity of ZF,and the unit cell parameter of ZF adsorbed Sr²⁺ decreases.

Design of Vacuum Releaser of the Primary Circuit of LingAo Nuclear Power Plant

LI Chunmei, LUO Mingkun, LI Shuzhou, NIU Wenhua, YANG Hong, CUI Huaiming

2010, 31(2): 94-97.

Abstract(10)

Abstract:
This thesis describes the design scheme,main capability parameter,relative technical reform and operation process etc.of the vacuum releaser of the primary circuit system of LingAo nuclear power plant.After the vacuum releaser of the primary circuit system being operated on site,the pressure of the primary circuit system can be below 0.02 MPa.abs,it can save about 30 hours in filling water and draining air process of primary circuit system.The design parameter and operation parameter of the vacuum releaser of the primary circuit system are better than the similar equipment of foreign country.This technique replaces a number of previous processes of static and dynamic draining air in the large-scale domestic nuclear power plant before filling water of no-fuel hydrostatic test,it is the first time to realize the vacuum releasing air in the large-scale domestic nuclear power plant before filling water of no-fuel hydrostatic test.

3D Numerical Analysis and Optimization of Aerodynamic Performance of Turbine Blade

WANG Dingbiao, XIE Wen, ZHOU Junjie

2010, 31(2): 98-102,112.

Abstract(11)

Abstract:
To reduce the stator profile loss and improve the efficiency of the industrial steam turbine,a numerical analysis and optimization of the data for the steam turbine stator blade are conducted by the NUMECA,a CFD software.The result shows that,compared with the original blade,the "after loading" blade is with the best static pressure coefficient distribution,and effectively postpones the transition point position,reduces the radial pressure gradient of suction surface,and cut down the secondary flow loss effectively.The total pressure losses of the "after loading" blade is 1.03%,which is the least,and the single-stage efficiency is 94.462%,which is the maximum and increases 14.33%.Thus,the aerodynamic performance of stage is im-proved obviously,the profile loss decreases through using the "after loading" blade.

Reduction of Snubber in Nuclear Piping System Based on Numerical Simulation

CHEN Min, REN Chunling, WU Gaofeng, ZHANG Zhouhong

2010, 31(2): 103-107.

Abstract(9)

Abstract:
In order to remove the snubber in the nuclear-grade piping system,a numerical simulation method is adopted for the mechanical analysis of nuclear piping system based on the finite element program,and the piping stress,the displacements of nodes,and the support loads are obtained.The results are compared with and without the snubber,and the mechanical capability of the piping system still meets the design code through the changing of the function and position of supports as well as using the rigid supports according to these results.

A Discussion on Variation of RCC-M 2007

LI Xiaoyan, HU Yan, GAO Rui

2010, 31(2): 108-112.

Abstract(12)

Abstract:
The reason of the updating in RCC-M 2007 was analyzed.The reference standard updating and the variation of each chapter in RCC-M 2007,such as the classification,the qualification of equipment,materials,fabrication,welding and non-destructive examination methods,were introduced,which integrated the requirement variation of PED and ESPN.

Numerical Simulation on Heat Transfer Enhancement in Shell Side of Shell-and-Tube Heat Exchanger with Leading Type Shutter Baffles

GU Xin, DONG Qiwu, LIU Minshan, ZHOU Yaning

2010, 31(2): 113-117.

Abstract(6)

Abstract:
For overcoming the contradiction between the performance improvement and fluid flow resistance increase in shell-and-tube heat exchanger,a new concept of "Sideling Flow" in shell side is presented,and a type of new high efficiency energy saving shell-and-tube heat exchanger with leading type shutter baffles in shell side,sideling flow heat exchanger is invented.Besides,the"Field Synergy Principle" is adopted to analyze its heat transfer enhancement mechanism,and it is indicated that there is the perfect synergy between the velocity field and temperature grads field in shell side of this type of new heat exchanger.Effects of the structure parameters on the fluid flow and heat transfer are investigated through numerical simulation,and the numerical results are in good agreement with the experimental data.

Mathematical Modeling and Simulation Research of New Type Sodium Pump Based on Superconduct

YANG Zhida, ZANG Hengbo, WU Hongjun, SUN Haowei, HAN Weishi

2010, 31(2): 118-121,130.

Abstract(10)

Abstract:
Based on the previous study on electric magnetic pumps,a new sodium pump based on superconduct is put forward and mathematical model is established.Scheme of helix slice and scheme of rectangle tube are contrasted,and the simulation curves of flux to pump head increment are presented.The result indicates that the flux capability of the scheme of rectangle tube is better.The value of flux and pressure head increment can be regulated with the value of power supply current and magnetic induction.The result accords with the goal of low pressure head and high flux.

Research on Application of Complex-Genetic Algorithm in Nuclear Component Optimal Design

HE Shijing, YAN Changqi, WANG Jianjun, WANG Meng

2010, 31(2): 122-125,135.

Abstract(7)

Abstract:
Complex algorithm is one of the most commonly used methods in the mechanical design optimization,such as the optimization of nuclear component.An improved method,complex-genetic algorithm（CGA）,is developed based on traditional complex algorithm（TCA）,in which the disadvantages of TCA have been overcome.An optimal calculation,which represents the pressurizer,is carried out in order to analyze the optimization capability of CGA.The results show that CGA has better optimizing performance than TCA.

Experimental on Metering Characteristics of Multi-hole Orifice

MA Taiyi, WANG Dong, ZHANG Bingdong, LIN Zonghu

2010, 31(2): 126-130.

Abstract(11)

Abstract:
Multi-hole orifice（MO） as a new type of throttling element is designed,and the characteristics of the discharge coefficient,the head loss and anti-swirl performance are experimentally studied.Compared with that of the standard orifice,the discharge coefficient of MO is more stable,and less sensitive to the upstream swirl,and the head loss is close to that of the standard orifice.For the three pairs plate of equivalent β of 0.42,0.59,and 0.65,the variation of the MO’s discharge coefficient is lower than that of the standard orifice by 0.83%,2.02% and 1.67%,respectively.The MO performance is superior to the standard orifice in anti-swirl aspect for lower β（β=0.42）,while the situation becomes opposite for larger β（β=0.65）.

Feasibility Study on NPP Loading Pattern Search via Direct Optimization Method

XU Hua, JIANG Xiaofeng, ZHANG Shaohong

2010, 31(2): 131-135.

Abstract(9)

Abstract:
The direct optimization method based on the mixed integer linear programming is proposed to solve the very involved nuclear power plant loading pattern search problem.By the introduction of 0-1 decision variables into the neutron diffusion equation,the original loading pattern search problem is converted to an equivalent mathematical programming problem,and then the loading pattern search and evaluation processes are completed synchronously by exploiting the powerful commercialized mathematical programming problem solver.In this paper,the feasibility of the proposed method is preliminarily demonstrated by its test applications to a 1D and a 2D problem.Numerical results reveal that the proposed method is capable of finding good loading patterns,even the global optima.However,since the current model still takes too much time to find the optima,the proposed method needs to be further improved before it can be ready for engineering application.

Locomotion Precision and High-speed Stop Effect for Reactivity Stepping Mechanism of CFBR-Ⅱ

YE Cenming, ZHANG Yi, SUN Wenqing, JIANG Zhiguo

2010, 31(2): 136-139.

Abstract(9)

Abstract:
The mechanism for CFBR-Ⅱ reactor reactivity stepping control is Copley Corp.’s Servo Tube linear motor,which induces large reactivity step during burst pulse process.This paper comparatively measures the locomotion precision of the system with Hall sensor and micrometer,and then the high-speed stop effect is evaluated based on the measured velocity and displacement curves.

Power Spectrum Density Analysis System of ²⁵²Cf Neutron Signals

REN Yong, MI Deling, WEI Biao, FENG Peng

2010, 31(2): 140-144.

Abstract(9)

Abstract:
The power spectrum density analysis method is incorporated in the analysis of ²⁵²Cf fission neutron random signal.An actual spectrum density analytic system for ²⁵²Cf neutron signals is constructed,which combines the pulse-time collector and PC processor.The system can on-line acquire the time series data of neutron pulses（3 channels） based on FPGA and DSP,and then implement the data processing,corre-lation calculation,FFT calculation and power spectrum density calculation on PC.A reduced power spectrum algorithm is designed simultaneously.The system can exactly detect the ²⁵²Cf neutron pulse and effectively obtain the results of characteristic parameters such as correlation function and power spectrum density,and then provide the effective preparation for the dynamic parameters measurement of ²⁵²Cf neutron source or reactor.

2010 Vol. 31, No. 2