28 July 2012, Volume 30 Issue 21

    

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Spescial Issues
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  Several Hypothetical Scenarios for Nuclear Fuel Cycle of PWR in China Before 2050

  WU Ying;MU Qiang;MA Xubo;CAO Bo;OUYANG Xiaoping

  . 2012, 30(21): 19-25. https://doi.org/10.3981/j.issn.1000-7857.2012.21.001

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  Based on the medium and long-term development targets of nuclear power in China, the mainstream reactor types M310 and AP1000 are taken as research object, the several scenarios of nuclear fuel cycle of PWR are assumed before 2050 and their feasibilities are analyzed based on the fact that the fast reactor is planning to be built in China. The resource requirements for Uranium and Plutonium in the hypothetical scenarios of nuclear fuel cycle are carried out by using DESAE program. The results could provide a data reference for the China's nuclear energy development strategy. The comparison and analysis of calculation results show that the amount of natural Uranium saving mainly depends on the scale of PWR using MOX fuel.
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  The PRHR Cooling Capacity during the Fail of Normal Feedwater Flow Accident for AP1000

  MO Xiaojin;TONG Lili;CAO Xuewu

  . 2012, 30(21): 26-29. https://doi.org/10.3981/j.issn.1000-7857.2012.21.002

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  AP1000 is the third generation of innovation-typed nuclear power plant and widely adopts passive safety design to increase safety and efficiency. Particularly, a Passive Residual Heat Removal (PRHR) system is used to deal with the accident due to the failure of normal residual heat removal path. AP1000 plant model is established by using mechanism-based code. The plant model includes the Reactor Coolant System (RCS), Engineering Safety Features (ESFs), and part simplified second side system. And the fail of normal feedwater flow accident of AP1000 plant is selected to analyze the accident progression. The transient response, thermal-hydraulic phenomena, and the cooling capacity of the PRHR are focused on. The transfer heat power from PRHR to IRWST and reactor core decay power are compared with each other. The result shows that in the case of failure accident due to normal residual heat removal path, the removal heat power of PRHR Heat eXchanger (PRHR HX) is able to match with the reactor core decay power at the late stage of the accident, meets the requirements of sustainable long-term core cooling, and keeps the reactor system in the safe shutdown situation.
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  The Hydrogen Source and Hydrogen Mitigation Measurement during Severe Accidents for AP1000

  LI Jingxi;TONG Lili;CAO Xuewu

  . 2012, 30(21): 30-33. https://doi.org/10.3981/j.issn.1000-7857.2012.21.003

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  AP1000 model, including Reactor Coolant System(RCS), Engineering Safety Features (ESFs), and containment, is built by using the integrated severe analysis code. According to AP1000 Probability Risk Analysis (PRA), several typical sequences are selected. The accident progressions are analyzed and hydrogen sources are investigated. It indicates that 624kg hydrogen will be generated in pressure vessel induced by MB-LOCA. The model of hydrogen control system, which consists of 64 glow-up igniters and two Passive Autocatalytic Recombiners (PARs), is built to analyze the effectiveness of removing hydrogen and the combustion modes are identified by the Shapiro triangular diagram. The results show that hydrogen concentration could be controlled within the safety limits by using 64 glow-up igniters and two PARs to protect the containment integrity from hydrogen deflagration or detonation.
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  Heat Transfer Characteristics of Spray Cooling with High Heat Flux Dissipation

  MA Tengyue;CHENG Wenlong;LIU Qinie;

  . 2012, 30(21): 34-37. https://doi.org/10.3981/j.issn.1000-7857.2012.21.004

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  A closed loop experimental device of spray cooling is designed and constructed based on high heat flux dissipation. Hot surface heat flux is calculated by thermocouple; spray distribution of nozzle and grain diameter and size are measured by PDA. A mathematical model of spray cooling is presented based on bubble dynamics and heat transfer. The results of numerical simulation show the relationship between the spray height and the spray cooling curve. With the spray height increasing, the spray cooling heat transfer capacity is enhanced, consisting with the same trend by experiment. The heat transfer coefficients in different spray angle, pressure, and height are presented, and the spray cooling heat transfer characteristics are analyzed. The conclusion is that the spray cooling heat transfer capacity in two phase region is significantly enhanced, and spray cooling has an optimal spray height.
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  Preliminary Neutronics Design of Breed Blanket for Fusion-fission Hybrid Reactor

  ZHAO Fengchao;LI Zaixin

  . 2012, 30(21): 38-44. https://doi.org/10.3981/j.issn.1000-7857.2012.21.005

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  A preliminary neutronics design of breed blanket for fusion-fission hybrid reactor has been carried out based on the plasma parameters of International Thermonuclear Experimental Reactor (ITER) and casing structure. In the design of fast-fission breed blanket, the natural Uranium pebble bed is used as fuel and neutron multiplication and the Lithium silicate pebble bed is used as tritium breed material. By using FENDL21 nuclear database cross section library with native cross section library of MCNP nuclear database, the calculation and analysis are carried out with MCNP program. Through one-dimension calculation and analysis on different design proposals, a proper design proposal has been screened and then the three-dimension calculation and analysis have been implemented with the parameters of ITER. The calculation shows that the TBR of fusion-fission hybrid reactor is 1.13, it indicates that the design of breed blanket is able to meet self-sustaining of tritium and the calculation also indicates that the energy enlargement of fusion-fission hybrid reactor is 6.5 and Polonium breeding rate is 1.35, it means that the reactor is able to also product large quantities energy and Polonium and they could be used by light water reactor. Meanwhile, fission-breed ratio, power distribution, tritium production rate distribution, Polonium breeding distribution of blanket blocks, and blanket block 14 are also calculated and acquired.
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  Domestic Graphite Strength Test for HTR Engineering Verification

  HU Yuqin;SUN Libin;WANG Hongtao;SHI Li;MA Shaopeng;SU Qihui

  . 2012, 30(21): 45-50. https://doi.org/10.3981/j.issn.1000-7857.2012.21.006

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  The strength of domestic graphite (NG-CT-01) is studied by experiments. Considering the dispersion of graphite material strength, samples are cut with different positions, directions, and blocks. The tensile, compressive, and flexural strength of the material are tested according to the national standards. Compressive stress is based on the equivalent tensile stress that appears in the evaluation of the stress on graphite, and the graphite safety evaluation of the data is determined by the tensile strength of the experiment. Therefore, the minimum strength is given based on the calculation of the tensile strength for the measured data. For graphite strength safety evaluation, the graphite strength Weibull distribution must be known. By using the maximum likelihood method, two-parameter Weibull distribution parameters are fitted with the tensile strength of the experimental data by means of the software of Weibull++7. Experimental data are fitted by two-parameter Weibull distribution. The estimated Weibull parameters are modified by following the German HTGR design specifications KTA-3232 HTR Ceramic Pressure Vessels Internals(1992).It provides the basis parameters for the future validation static and dynamic experiments for HTR-PM projects. After comparing the experimental results, the conclusion could be drawn out that the graphite strength parameters have been improved based on the original data, and the parameters are able to basically meet the technical requirements for the structural and seismic engineering verification tests.
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  The Human Reliability in the Accident Processing of NPP

  GU Pengfei;ZHANG Jianbo;SUN Yongbin

  . 2012, 30(21): 51-55. https://doi.org/10.3981/j.issn.1000-7857.2012.21.007

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  Recently, Human Reliability Analysis (HRA) is becoming more important to the safety of Nuclear Power Plant (NPP). Since the digital technology is adopted in the control room of NPP, the computerized operator workstations have brought flexible operation methods. However, huge and centralized information also could cause some risks for operation tasks. Therefore, as the reliability of the NPP equipments have been increased even higher, HRA should be developed in order to guarantee the better safety of NPP. According to the new revision of NUREG 0700 Standard published by Brookhaven National Laboratory in USA, Advanced Control Room (ACR) has been defined as the control room adopted the digital technology. In China, self-determination design involving ACR is first beginning with Lingao Phase II project. Lingao Phase II NPP has been in operation mode since the year of 2010. It indicates the success of first self-determination design involving ACR. The design process of ACR is focused on. In the analysis, the LOCA and SGTR are selected as the initiating events. And based on that, some failures of other equipments or systems have been added. Then the process that the operators deal with the accidents has been analyzed with the accident situations in order to obtain reasonable human performance data. By collecting human performance, especially in accident situations, it shows that enhancing the human reliability is very important. Therefore it would be benefit to analyze the human reliability. As a result, it also could be benefit to the design improvement of NPP, specially the design of main control room.
Articles
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  Clinical Validation of an Enrichment and Identificationmethod of Circulating Tumor Cells in Breast Cancer Patients

  XING Xiaoyan;WANG Dongmin

  . 2012, 30(21): 56-60. https://doi.org/10.3981/j.issn.1000-7857.2012.21.008

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  An effective enrichment and identification method of Circulating Tumor Cells (CTC) was clinically validated and the specificity and sensitivity of the method in CTCs detection from breast cancer patients was evaluated as well in this paper. Fluorescent labeled cultured breast cancer cell line, SKBR-3 cells were added into 7.5mL peripheral blood obtained from ten of healthy volunteers respectively in this paper. After enrichment by using anti-leukocyte antigen antibody conjugated nanobeads, the slides were observed with fluorescent microscope and the fluorescent labeled cells were counted. The enrichment efficiency was evaluated by average cells recovery rate. The peripheral bloods from 20 of healthy volunteers and 15 of patients with clinical diagnosis of invasive breast cancer were extracted and blind coded. Then the CTCs were enriched and identified by immunofluorescent plus immunocytochemical stains. By comparing the difference of CTCs number between healthy volunteers and breast cancer patients, the specificity and sensitivity of the method were evaluated. The results show that the average spiked cells recovery rate was 75%. The spiked cells were anti-keratin (CK18) stain positive, anti-Her2 stain positive and anti-CD45 stain negative, which consist with the antigen expression characters of breast cancer cells. The unblinding result revealed that there were none of CTCs found in bloods from 20 of healthy volunteers, while among 15 of breast cancer patients, less than 3 CTCs (0—2) were detected in 33.3% patients and more than 3 CTCs were detected in 66.7% patients. The enrichment and identification method used could well recover spiked cells in peripheral blood and have significant specificity and sensitivity in CTCs clinical detection.
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  Airworthiness Certification Calculation Method of Gas Turbine Engine NO_x Emissions Based on LTO Cycle

  HOU Xiaoyun;ZHANG Tiangang

  . 2012, 30(21): 61-65. https://doi.org/10.3981/j.issn.1000-7857.2012.21.009

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  The airworthiness certification is necessary before the aircraft enters into the commercial operation. The requirement of the airworthiness is the basic regulation guarantee for the safe flight of aircraft; therefore it is necessary to study the airworthiness certification method for gas turbine engine emissions. In order to solve the technical difficulty of the methods involving gas turbine engine emission test data and meet the requirement for engine emissions airworthiness certification standard, an emission measuring system is designed with reference to Aircraft Engine Emissions promulgated by the convention of ICAO. The accuracy of this system is no more than 7%, it is much better than 10%—15% based on the procedure for the analysis and evaluation of gaseous emissions from aircraft engines requirement, so that the sampling and measurement system is proved feasible. Calculation of NO_x emission index from aircraft is developed by using ICAO method based on the ICAO standard involving Landing and Take-Off (LTO) cycle. JT3D-7 NO_x emission is compatible with the existing regulatory standards according to CCAR-34. According to the method of ICAO, a system for the airworthiness certification of gas turbine engine emissions is developed by MFC and NO_x emission index of the engine could be quickly computed.
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  The Design of Dynamic Acquisition System for Intraocular Pressure and Fundus Image

  ZHAO Xingqun;SHEN Yanwan

  . 2012, 30(21): 66-71. https://doi.org/10.3981/j.issn.1000-7857.2012.21.010

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  Glaucoma is the degeneration of the optic nerve head caused by elevated Intraocular Pressure (IOP) and diurnal variations. It is the second leading cause of blindness. The pathogen of glaucoma is very complex. Although abnormal elevation of IOP is the main reason, visual field defects and optic disc changes in eyes are also the symptoms. Therefore, IOP and fundus are two important and indispensable parameters for the diagnosis of glaucoma. Based on the principle of Goldmann applanation tonometer, the IOP measurement and fundus image are obtained by a single measurement. FPGA is the core unit of this design, the value of IOP and the acquisition of dynamic fundus images are measured by the optical probe which is pushed to contact the eye. IOP is measured by the software of Nios II which controls the probe pressure by using embedded soft-core. The value is indirectly calculated through selected appropriate algorithm of image segmentation for corneal flattening area. Design of dynamic fundus image acquisition system includes lighting system and observation system. The lighting system is made up of Cora lighting. The observation system acquires flattening corneal images and the fundus images in the process by means of imaging sensor. In order to verify the function of this system, the experiments, such as simulated eyeball and live animals, are carried out. The system is able to calculate IOP, acquire real-time dynamic images, and display and store images quickly and easily. It provides two important and indispensable parameters for the diagnosis of glaucoma.
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  Optimization of Flexible Shield Supports Mining Method for Steeply Coal Seam in Daanshan Colliery

  HUO Bingjie;ZHANG Hongwei;ZHANG Maolin

  . 2012, 30(21): 72-75. https://doi.org/10.3981/j.issn.1000-7857.2012.21.011

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  With the demand for coal increasing, it is necessary to mine the steeply coal seams. The flexible shield supports mining method is a safe and efficient mining method for the steeply coal seams. It was first time employed in Huainan mining district in the 1970s. The flexible shield supports method is optimized on the basis of practices in Daanshan colliery for improving the work efficiency of steeply coal seam. The flexible shield supports method is optimized mainly on the entry layout and winning technology in order to improve the security, yield, and work efficiency by analyzing the distinctive features and adaptability of flexible shield supports method in Daanshan colliery. The mainly optimization contents include the entry layout and the coal breaking technology. One is increasing the angle of working face and changing mining traffic road from 23° to 28°; and the other is transforming from bench blasting technology to piecewise blasting technology. The advantages of the optimized flexible shield supports method are that the slope development length and the post-blasting blockage probability of the working face are reduced, transportation capacity is increased at the working face and slope, and the efficiency is improved.
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  Effectiveness of the Sand out Monitoring Method by Applying Vibration Signal Analysis

  LIU Gang;HAN Jinliang;CHEN Chao;YANG Quanzhi;LI Yuhong

  . 2012, 30(21): 76-79. https://doi.org/10.3981/j.issn.1000-7857.2012.21.012

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  The moderate sand mining technology of heavy oil field needs one kind of effective real-time monitoring system for monitoring the signal of sand out. However, the existing measuring methods, such as acoustic method and electrical resistant method, all have different problems in the actual productions. To solve these problems, a proposal that the sand fluid impact wall vibrations signal could be used as a new way for sand out monitoring is offered. In order to verify the effectiveness of the approach, a simulation system of sand out from well has been established in the laboratory, the system accepts the vibration signals of sand impact by using the acceleration sensor, and the dynamic signal processing method is adopted to process the data. In order to make the experiments consistence with actual situations, the high viscosity of gear oil is used to simulate the heavy oil in the system, and piston pump and heating blender is used to realize the simulation of sand out from oil well production. The apparent vibration signal of sand out is able to receive by the system. Through the dynamic signal analysis method, the data is processed using power spectrum analysis. The system could effectively monitor the change of sand content as the sand content increasing, the variance value, mean square root value, power spectrum amplitude of sand vibration signal and characteristic value of signals will increase. By the means of processing data, the test indicates that using the vibration signal from sand for monitoring sand out has the good effectiveness.