核动力工程

Full Multi-grid Diffusion Synthetic Accelerated Discrete-Ordinates Neutron Transport Numerical Computation Code SN3C

LIU Yong-kang, HU Yong-ming, LIU Han-gang, QIAN Da-zhi

2006, 27(5): 1-5,11.

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To improve the performance of the recently developed three-dimensional neutron transport code SN3C,the consistent Diffusion Synthetic Acceleration（DSA） method and the self-adapting Chebyshev polynomial acceleration method were adopted to accelerate the source iteration and power iteration,respectively.According to the characteristics of the method used by the DSA for solving the diffusion equa-tion,the author had developed the Full Multi-grid Diffusion Synthetic Method（FMDSA）,which based on the Full Multi-grid Algorithm.The results of benchmark calculation showed a good agreement with reference value.The performance of FMDSA was demonstrated as good as the block-SOR with optimal relaxation fac-tor for little and medium problems,and moreover,for a large-scale problem,it was better than the latter.

Nodal S_N Method for Neutron Transport Equation in Triangular Geometry

LU Hao-liang, WU Hong-chun, CAO Liang-zhi, ZHOU Yong-qiang, XIAN Chun-yu, YAO Dong

2006, 27(5): 6-11.

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Using the theory of area coordinate,arbitrary triangles were transformed into regular triangles.The transverse integration was done on the regular triangle.The spatial distribution of intra-node flux and source were approximated by a new orthogonal quadratic polynomial expansion,and a second-order polyno-mial provided the spatial expansion of transverse-leakage.The neutron angular distribution of flux and trans-verse-leakage were represented by the S_N quadrature set.Additionally,the nodal-equivalent finite difference algorithm was applied in order to establish a stable and efficient iterative scheme.A two-dimension triangular nodal S_N transport calculation program（DNTR） was coded according to the model.A series of numerical results for the test problems demonstrate that this triangular nodal S_N method is faster 5 to 7 times than the fine mesh difference code（DOT4.2） with the same precision and faster 1 to 3 times than the rectangular dis-crete nodal transport method（DNTM） with the same precision and equal mesh width.However,this method can be applied to solve the unstructured neutron transport problems,and has an unexampled advantage of the nodal S_N methods used on the structured meshes,such as DNTM.

Study of Transmission Probability Method Based on Triangle Meshes

LIU Ping-ping, WU Hong-chun

2006, 27(5): 12-18,41.

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Transmission Probability Method based on triangle meshes is studied in this paper.The inte-rior source is assumed to be isotropic in angular distribution and constant in spatial distribution.The surface angular flux is assumed to be with simplified 4P₁ approximation in angle and average in space.A new grid sweep process based on unstructured-mesh coding number is adopted.TPTRI program is encoded which can be applied to the solution of neutron transport of arbitrary two-dimensional geometry.Several benchmark problems are calculated and the results are compared with MG-MCNP3B,SURCU and TEPFEM programs.The numerical analyses show that the results of TPTRI are in good agreements with that from other programs.

Analysis of Soil-Structure Interaction and Floor Response Spectrum of Reactor Building for China Advanced Research Reactor

RONG Feng, WANG Jia-chun, HE Shu-yan, DONG Zhan-fa

2006, 27(5): 19-23.

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Analysis of Soil-Structure Interaction（SSI） and calculation of Floor Response Spectrum（FRS） is substantial for anti-seismic design for China Advanced Research Reactor（CARR） project.The article uses direct method to analyze the seismic reaction of the reactor building in considering soil-structure interaction by establishing two-dimensional soil-structure co-acting model for analyzing and inputting of seismic waves from three directions respectively.The seismic response and floor response spectrum of foundation and floors of the building under different cases have been calculated.

Evaluation on Influence of Modification of Surge Line Piping Arrangement on Seismic Responses

LI Zhong-cheng, MA Zi-rong

2006, 27(5): 24-28,57.

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To alleviate the thermal stress and fatigue induced by thermal layer separation and improve the erection conditions,the modification,enlarging the angle between surge line piping and primary piping and installing the pressurizer at a higher level,has been taken into account in the new design based on M310 model.This modification can bring the changes of the internal structure arrangement of reactor building and lead to a set of different seismic responses to some extend.A new structure model to account for the modifica-tion is constructed.The seismic system analysis is conducted based respectively on the new and old model,and the results are compared with each other so as to evaluate the differences of seismic responses in two cases.Some conclusions can be provided as reference to evaluate the feasibility of this modification.

Numerical Study of Water Film Wave Flowing on Wall

TIAN Rui-feng, LI Zhao-jun, ZHANG Qing-wu

2006, 27(5): 29-32.

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The flowing characteristic of water film on wall is one of the main factors that influences the secondary droplets entrainment.This paper studies the flowing characteristic of water film on wall of certain sizes,using numerical method.Based on the analysis of water film surface forces,the dynamic boundary condition of water film free surface was obtained,and the wave flow models of water film on wall were es-tablished.The central-differencing algorithm was used for the continuity equation.And the blend of two-order upwind difference algorithm and central-differencing algorithm was used for the Momentum equation.SIM-PLE and VOF algorithm were used to solver the wave flow of water film on wall.Calculation results showed that the water file waved more acutely in the middle of wall than other places,and the inlet interferential fre-quency influenced the wave flow of water film more intensively than the inlet interferential.

Experimental Research of Effect of Rolling upon Heat Transfer Characteristic of Natural Circulation

TAN Si-chao, PANG Feng-ge, GAO Pu-zhen

2006, 27(5): 33-36,69.

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The Effect of rolling upon heat transfer characteristic of single-phase natural circulation is experimentally studied in the paper.The results show that heat transfer of natural circulation under rolling is enhanced.Heat transfer coefficient increases with rolling amplitude and rolling frequency increasing.The present empirical correlation to predict heat transfer coefficient under rolling motion derived from the experimental data processing is also discussed in this paper.

Statistical Measurement of Radial Void Fraction Distribution of Bubbly Flow in a Vertical Pipe

ZHU Xue-cheng, LUO Rui, SUN Yan-fei, YANG Xian-yong

2006, 27(5): 37-41.

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An image-based method has been developed for measuring the instantaneous radial void fraction distribution in bubbly flows with higher void fractions in a vertical pipe.The method is based on the statistical analysis to shadow images of a bubbly flow,which were obtained using a stereo photographic tech-nique.The projection void fraction distribution was obtained,by counting all pixels of bubble shadow images and considering the overlapping probability of the bubble shadows.Then the instantaneous radial void frac-tion distribution in the bubbly flow was reconstructed from projection void fraction distributions on the as-sumption that the radial void fraction distribution is axial symmetrical.An improved algorithm for Abel inver-sion calculation has been proposed to reconstruct the radial distribution of the local void fraction based on the Fourier method.Finally,the method is checked for the accuracy in the measurement of the radial bubbles dis-tribution by comparing with the labeling method results.The comparison results showed that some special void fraction profiles,such as the wall-peaked or high void fraction distributions that usually cannot be ob-tained by other methods,could be measured by this method.

Investigation of Critical Heat Flux of Annular Flow in Vertical Upward Round Tube

FAN Pu, QIU Sui-zheng, JIA Dou-nan

2006, 27(5): 42-47.

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Prediction of Critical Heat Flux at high mass quality is important for the safety of once-through steam generator and the reactor core under accidental conditions.Based on the theory for droplet entrainment,droplet deposition and liquid film evaporation,the film thickness and film mass flow rate dis-tribution along axis are calculated at vertical upward round tube.The dryout emerges at the point where the film is depleted due to the balance of entrainment,deposition and evaporation.The theoretical CHF values are higher than that of experimental data,with error within 30%.

Flow Patterns of Air-Water Two-Phase Flow in Vertical Noncircular Channels

GUO Ya-jun, BI Qin-cheng, HE Yong-qing, ZHOU Ying, CHEN Ting-kuan

2006, 27(5): 48-52,73.

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Experimental investigations on air-water two-phase flow in a vertical circular channel and three noncircular channels（an equilateral triangular channel and two square channels） were carried out.The hydraulic diameters of the channels are 14mm,14.43mm,15mm and 10mm,respectively.Superficial air ve-locity and water velocity are about: V_SG =0.04~80m/s,V_SL=0.001~6 m/s.The following typical flow patterns for the channels at different air and water superficial velocities were recognized by flow visualization: bubble flow,slug flow,churn flow,annular flow,dispersed bubble flow,and creep flow（or rivulet flow for the cir-cular channel）.The observation of creep flow in noncircular channels has proved that the influence of the channel geometry results in the steeper radial distribution of the phases and velocities,and eventually turbu-lent secondary flow,which affects two-phase flow patterns in noncircular channels at high air superficial velocities.The secondary flow in a triangular channel is stronger than that in a square channel,it proves that the influence of the channel geometry is of significance.The flow pattern maps and flow pattern transition boundaries were obtained.Comparison with the previous literatures shows that the influences of the channel geometry and hydraulic diameter on the flow pattern transition do exist.

Study on Dislocation Configuration of N18 Zircaloy Containing Hydrides after Cyclic Deformation

TAN Jun, YING Shi-hao, LI Cong, ZUO Ru-lin, SUN Chao

2006, 27(5): 53-57.

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The dislocation configuration and the interaction between hydrides and dislocations of N18 Zircaloy after cyclic deformation at room temperature have been investigated,using transmission electron microscopy.The results show that there existed many dispersing precipitated particles in N18 Zircaloy,and that the dislocation configuration was characterized by dislocation lines pinned by precipitate particles whichThe dislocation configuration and the interaction between hydrides and dislocations of N18 Zircaloy after cyclic deformation at room temperature have been investigated,using transmission electron microscopy.The results show that there existed many dispersing precipitated particles in N18 Zircaloy,and that the dislocation configuration was characterized by dislocation lines pinned by precipitate particles which were formed by { 10$\overline{1}$ 0} prismatic slip.In the process of deformation,only part of grains deformed plastically while the others were in elastic state.The hydrides in N18 Zircaloy specimen were mainly composed of δ phase zirconium hydrides with F.C.C structure.Hydrides had a “size effect” on dislocation motion,i.e.the hydrides in small size could be cut open by dislocation slip while those in big size could not.

Fast Neutron Flux Calculation of Welding Line in Pressure Vessel of High Flux Engineering Test Reactor

QIU Li-qing, FU Rong, QIN Le-gang, DENG Cai-yu, WANG Qing-mei

2006, 27(5): 58-60,73.

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This paper calculated the fast neutron flux of some places in different HFETR cores,such as the 13^rd ion chamber and L12 fuel rod in the 1^st core,the 12^nd ion chamber and the 1QS ion chamber in the 68^th –II core.Comparison of the calculated and the experimental results was made.It showed that the result was accurate.And we also chose different cores to get the fast neutron fluence of welding line in the reactor pressure vessel of HFETR up to 2004.The result was 1.212×10¹⁷cm^-2（^E≥1MeV） and 2.514×10¹⁷cm^-2（^E≥0.1MeV）.It showed that the maximum fast neutron fluence was less than the design data so far.

Experimental Research on Non-proportionally Multi-axial Ratcheting of 304 Stainless Steel at High Temperatures

ZHANG Juan, KANG Guo-zheng, GAO Qing, SUN Ya-fang

2006, 27(5): 61-64.

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In order to accurately describe the ratcheting behavior of material at high temperature,an experimental research was carried out on the uni-axial and non-proportionally multi-axial ratcheting of 304 stainless steel at 350℃ and 70 0℃.The ratcheting behavior under different loading paths and different load conditions was studied.It was shown from the study that the non-proportionally multi-axial ratcheting of 304 stainless steel at high temperatures has distinct dependence on the stress amplitude,mean stress,temperatures and loading paths.This result is useful to establish constitutive model for the non-proportionally multi-axial ratcheting of material at high temperature.

PCI Analysis during Rod Drop Transient

LIU Tong, ZHANG Lin, SHEN Cai-fen, XIAO Zhong, LÜ Hua-quan

2006, 27(5): 65-69.

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During rod drop transient,the interaction between pellet and cladding increases instantly,which may leads to failure of fuel rod.This paper introduces the mechanism and quantative method to analyze PCI during transient II,with which the PCI thermal-mechanical analysis has been carried out for the 18-month fuel cycle management of GNPS.The results show there are enough stress margins for the base load operation and primary frequency control operation if rod drop accident occurs in the natural cycle and stretch out operation,therefore no risk of PCI failure has been found.

Safety Analysis of NPP Spent Fuel Pit When Losing of Final Heat Trap

LI Can, LING Xing

2006, 27(5): 70-73.

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The equipment cooling water used in primary circuit loop and spent fuel system is provided by seawater cooler in nuclear power station.A hypothesis is the seawater cooler quit operation as certain accidents occurred.By employing heat balance equation,we have calculated and analyzed safety of the spent fuel pit and possibility of cooling other important primary circuit loop user.Our results show that the spent fuel pit operates safely at various situations in this paper.Except one condition,cooling water in the spent fuel pit is available to cool other equipments.

Contrastive Research on Two Kinds of Real-Time Fault Diagnosis Systems of Nuclear Power Plants

LIU Yong-kuo, XIE Chun-li, XIA Hong, YAN Chang-qi

2006, 27(5): 74-78.

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In order to guarantee the safe operation of nuclear power plants,the real-time fault diagnosis systems are developed using neural network technology and data fusion technology and adopting VB6.0 pro-gramming languages,and then the intelligence diagnosis arithmetic is expatiated in detail.The fault diagnosis systems interchange the data with the simulator timely utilizing communication procedure interface of the data,and four faults are inserted on the simulator to test the two diagnosis systems on line.The test result indicates that the fuzzy neural network technology and the data fusion technology could carry out the recog-nition of the faults,but each has its merit and the insufficiency respectively.The off-line analysis shows that,for different fault types,when there is few characteristic parameters,the fuzzy neural network diagnosis technology is better;when there are many characteristic parameter,the data fusion diagnosis technology is better.

Reliability Assessment Methods with Small-Sample for Device with Only Safe-or-Failure Pattern

ZHANG Shi-feng, YANG Hua-bo, ZHANG Jin-huai

2006, 27(5): 79-83.

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Reliability assessment methods for devices with small-sample high-reliability safe-or-failure pattern are difficult problems in nuclear engineering and aerospace engineering.Some reliability assessment methods are analyzed thoroughly,including Bayesian statistics,improved Bayesian approach and Bayesian networks.Meanwhile the corresponding simulation examples are given to explain the application of the methods.Finally,some conclusions and advices are proposed for the device reliability assessment with only safe-or-failure pattern.

Vibration Safety Analysis of Fan Blades

CHEN Jie, SHEN Rong-ying, HUA Hong-xing, LUO Jian-ping

2006, 27(5): 84-86.

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The traditional frequency adjusting method for blade vibration safety analysis has four inherent limitations.To avoid these limitations a dynamic stress analysis method is introduced.The method can be used for fan blade dynamic stress and vibration safety analysis,even the practical dynamic load is unknown.An example is given toverify the method.

Optimization Study on Shielding Design for Horizontal Ducts of China Advanced Research Reactor

SHI Xiu-an, LIU Zhi-hong, HU Yong-ming

2006, 27(5): 87-90,93.

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Considering the radiation security and economy factors,optimization study is done on the shielding design for the horizontal heat source ducts of China advanced research reactor（CARR）.Disadvan-tages of time consuming and inaccurate calculation results with MCNP4C when calculating the deep penetra-tion problems are avoided by step calculation.When re-building the model,the optimization problem of shielding design for revolving door is converted into a combined optimization problem of shielding materials.Characteristic statistic algorithm（CSA） is combined with ANISN program and then optimization program of shielding design is developed.After searching for large numbers of schemes,the optimal scheme of optCH2 is found,which meets the need of radiation security,economy and mechanical performance of materials.Then optimal scheme is calculated using MCNP4C program and compared with the former ones.The results show that the optCH2 scheme is much better than the original one both in security and economy.

Nuclear Safety Management and Control on Material Issue of Leak-tight Liner of Ling’ao Nuclear Power Plant Unit 3

CHEN Min, WANG Rui-ping, FU Jin-liang, YANG Kai, CHEN Rong-da

2006, 27(5): 91-93.

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This paper introduces the inspection by Guangdong Regional Office（GRO） of the leak-tight liner of the 3^rd unit of Ling’ao Nuclear Power Plant.During the inspection,the inspectors from GRO found some problems,including the material of the liner not in accordance with PASR and RCC-G,and Non-Conformance management.The occurrence of this non-conformance and its disposal reveal that it is necessary,for the manufacture and purchase of safety important components,to strengthen the regulatory inspection and to enhance the quality assurance,during the plant construction stage.

Fuel Handling System of 10MW High Temperature Gas Cooling Reactor Based on LabVIEW

LI Zhi-hui, HU Shou-yin, LIANG Xi-hua

2006, 27(5): 94-96.

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The field multi-channel signals has been acquired synchronously from 10MW High tempera-ture gas cooling reactor fuel handling system by DAQ technology.Counting software is developed based on LabVIEW.Its virtual instrument is flexible and user-friendly,and can count fuel-ball exactly.

2006 Vol. 27, No. 5