广东核电基于知识库的决策支持系统

决策支持系统是决策者有力的辅助决策工具,构建决策支持系统是一项复杂的系统工程.以广东核电信息建设为背景,介绍决策支持系统的构建过程.基本方法是,以关系数据库为基础进行知识的组织、挖掘与获取、构建知识库,然后构建基于知识库的决策支持系统.实践表明,该方法有一定的实用价值.     

Evaluation methodology for seismic base isolation of nuclear equipments

An evaluation methodology for seismic base isolated nuclear equipments is proposed. The evaluation can be classified into two steps. In the first step, the seismic functional failure probability during the lifetime of equipment without base isolation devices is quantified in order to decide the applicability of the base isolated structure. The second step is comparative and calculates the ratio of the seismic failure frequency of the equipment without base isolation devices to that with them in order to evaluate the effectiveness of the base isolated structure. The sample evaluation considers the case of high voltage type emergency transformer with ceramic tubes.     

Adaptive fuzzy system for fuel rod cladding failure in nuclear power plant

A new approach to the study of ballooning that causes cladding failure in fuel rods using an adaptive neural fuzzy inference system (ANFIS) is presented in this paper. By mapping input/output patterns describing cladding failure phenomena through average inner cladding temperature and fuel rod gas pressure, ANFIS shows a great potential to modeling this problem in alternative to the traditional approach. A typical pressurized water reactor fuel rod data was used to this application. The results confirm the potential of ANFIS comparatively to experimental calculations.     

Damping characteristic identification for a nonlinear seismic isolation system

The steady-state response of structures to harmonic excitation is of both direct and indirect importance. Such a response is of obvious direct importance in problems which involve excitation from rotating machinery or other sources of steady harmonic excitation. It is also of indirect importance in problems involving transient excitation where knowledge of the harmonic response may be used in estimating and interpreting the transient structural response. For example, the “effective” natural frequencies, damping ratios and mode shapes identified from full-scale harmonic tests of structures are often used to interpret the transient non-linear response of these structures to earthquakes. The non-linearity is confined to the connection between the structure and the moving base. This system might be a highly idealized model for a reactor structure including non-linear seismic isolation effects.In this paper a phase resonance method is given for damping characteristic identification of the nonlinear device seismic isolation in the harmonic excitation case. The method allows the shape of the symmetric function of the system to be determined, when is not known. If F_d(x) is asymmetric then the elasticity characteristic should be known.The identification algorithm has been derived assuming that F_d(x) is given in an analytic form. The validity of the method was checked for some systems with strongly nonlinear damping characteristics.     

Development of an ultra sonic phased array system for nondestructive tests of nuclear power plant components

A phased array ultrasonic inspection (PAULI) system is being developed to obtain electronically scanned ultrasonic images of the inside of nuclear power plant components for nondestructive evaluation. The development strategy of PAULI system was the modification of a medical ultrasound imaging system that had 64 individual transceiver channels. Optimization of array transducers has been also pursued based on the systematic investigation of the radiation beam field simulated by the use of the boundary diffraction wave models. 7.5 MHz phased array transducers was, then, fabricated and tested with the carbon steel specimen having side-drilled holes. For the nondestructive tests on power plant component, a sample mockup of turbine blade root with EDM notches was fabricated and the detection capability was demonstrated. The developed system can provide electronically scanned ultrasonic images in real time fashion and greatly enhance the efficiency and reliability in the flaw detection and location in comparison with the classical ultrasonic testing (UT) using A-scan signals. For the flaw classification, the analysis of the electronically scanned ultrasonic images was not sufficient at this moment but analysis of features obtained from A-scan signals of flaws at the various steering angles showed the potential capability.     

Protection for structures in extreme earthquakes: Full base isolation (3-D) by the Swiss seismafloat system

Full Base Isolation (FBI, 3-D), an antiseismic concept for structures, adds vertical flexibility to horizontal base isolation (HBI, 2-D). Extensive experimental testing at the Swiss Federal Institute of Technology and the University of California, Berkeley, has shown FBI to be a practicable way to reach the final goal of earthquake protection, i.e. elastic behavior of the structural frame in extreme earthquakes. Swiss engineers pioneered base isolation by the construction of the Pestalozzi School at Skopje in 1968. Further development has made Integral Earthquake Protection possible for structures and their contents.     

时间触发系统用PMT性能测试研究

通过基于Windows XP环境的VME数据获取系统,对MRPC束流实验中时间触发系统(T0)的光电倍增管(PMT)进行性能测试研究.从精确测试获取的PMT单光电子峰的角度出发,依据电荷谱的能量分辨率、峰谷比值、增益等条件确定PMT合适的工作高压.依据时间和幅度信息的匹配关系,对不同入射光子的数据进行挑选,进而改善测试数据的时间分辨.     

电子束辐照对进口葡萄色泽及保鲜效果的影响

以美国进口葡萄（无核红提）为试材,用剂量为0、0．56、1．11和2．10kGy的电子束辐照后分别于室温（13—17℃）下贮藏7d,低温（4℃±1℃）下贮藏15d。采用单-pH法和色度空间法测定果皮花青素含量和色差变化,用硬度计检测果肉耐压力。结果表明,电子束辐照导致葡萄果皮花青素含量下降,其下降幅度随剂量增加而加大,其中2．10kGy辐照果皮花青素含量显著低于未辐照处理。电子束处理对葡萄果实耐压力产生影响,但与剂量无相关性,其中室温贮藏葡萄的果实耐压力低于相应未辐照处理,低温贮藏15d时,0．56kGy电子束处理的果实耐压力高于相应未辐照处理。电子束处理可减少葡萄微生物数量,且剂量越高,微生物数量越少,腐烂率越低,可保证较好的防腐效果。     

A model for the coupling of failure rates in a redundant system

A model is developed which takes into account the coupling between failure rates of identical components in different redundancies of a safety system, i.e., the fact that the failure rates of identical components subjected to the same operating conditions will scatter less than the failure rates of any two components of the same type. It is shown that with increasing coupling the expectation value and the variance of the distribution of the failure probability of the redundant system increases. A consistent way to incorporate operating experience in a Bayesian framework is developed and the results are presented.     

Estimation of common cause failure parameters with periodic tests

In the specific case of safety systems, CCF parameters estimators for standby components depend on the periodic test schemes. Classically, the testing schemes are either staggered (alternation of tests on redundant components) or non-staggered (all components are tested at the same time). In reality, periodic tests schemes performed on safety components are more complex and combine staggered tests, when the plant is in operation, to non-staggered tests during maintenance and refueling outage periods of the installation. Moreover, the CCF parameters estimators described in the US literature are derived in a consistent way with US Technical Specifications constraints that do not apply on the French Nuclear Power Plants for staggered tests on standby components. Given these issues, the evaluation of CCF parameters from the operating feedback data available within EDF implies the development of methodologies that integrate the testing schemes specificities. This paper aims to formally propose a solution for the estimation of CCF parameters given two distinct difficulties respectively related to a mixed testing scheme and to the consistency with EDF’s specific practices inducing systematic non-simultaneity of the observed failures in a staggered testing scheme.     

Design failure mode and effect analysis for Korean fusion DEMO plant

The construction of Korean Fusion DEMO Plant (KFDP) for a demonstration of the plasma analysis and engineering feasibilities is planned in 2030s based on the Korean fusion technology roadmap. The radiation safety should be assured for nuclear facilities, so that, the KFDP is required to research for the regulatory requirements and industrial codes and standards. The final design guidance of the engineered safety features should be served in future. As the first step for this research, the failure modes and effects analysis in a design stage was performed. This leads to find the list of potential hazard elements and to obtain the list of initiating events for the future probabilistic risk assessment. The hazard elements expected to seriously threaten the integrity of the KFDP were investigated and determined to quantify the effect of the initiating events in the effect analysis: (1) a total loss of active cooling water to occur during the burn with decay heat calculation and (2) coolant ingress from cooling circuits into the vacuum vessel, cryostat and containment building. For those initiating events, the quantitative simulations using transient mass and energy calculation and computational fluid dynamics were performed.     

Variable friction pendulum system for seismic isolation of liquid storage tanks

Earthquake response of liquid storage steel tanks isolated with variable friction pendulum system (VFPS) is investigated under normal component of six recorded near-fault ground motions. The continuous liquid mass of the tank is modeled as lumped masses known as sloshing mass, impulsive mass and rigid mass. The corresponding stiffness constants associated with these lumped masses are worked out depending upon the properties of the tank wall and liquid mass. The governing equations of motion of the tanks isolated with variable friction pendulum system are derived and solved by Newmark's step-by-step method assuming linear variation of acceleration over small time interval. In order to verify the effectiveness of the VFPS in tanks, the seismic response of tanks isolated with VFPS is compared with that of the same tanks isolated using the conventional friction pendulum system (FPS). Furthermore, a parametric study is also carried out to critically examine the behaviour of tanks isolated with VFPS. The various important parameters considered are the tank aspect ratio, the isolation period and initial time period of the VFPS. In addition, the seismic response of tanks isolated with VFPS under trigonometric cycloidal pulses is also investigated. From these investigations, it is concluded that with the installation of VFPS in tanks, the seismic response of tanks during near-fault ground motions can be controlled within a desirable range. Finally, it is also observed that the response of tanks isolated with VFPS under the near-fault ground motions and trigonometric cycloidal pulses matches well only when the isolation period reaches high values.     

基于TMS320VC5402控制系统并行引导方式设计

介绍了TMS320VC5402并行Bootloader的原理.为实现脱机运行,充分利用其片内掩膜ROM带有一个引导装载程序Bootloader,实现对用户程序的并行引导装载.同时采用CPLD编程技术提供了一种实用的扩展存储器设计方案.     

Study on nuclear power plant simulator for digital I&C system commissioning

介绍了开发的核电站仿真机结构及功能,接着以稳压器压力控制系统为例,利用该仿真机进行了现场DCS调试的应用研究.先测试确保其DCS逻辑功能,然后通过与核电厂实际测试结果对比分析后,改进仿真机模型,最后对现场DCS进行了参数优化.研究表明,仿真机应用于核电站现场DCS测试及参数优化调试具有节省现场调试时间、降低调试风险的优越性.     

In situ dynamic tests and seismic records on the RHR system building enel IV nuclear plant/caorso (Italy)

The tests on the RHR Building of the Caorso Nuclear Plant are part of a program of dynamic tests on large structures sponsored by ENEL, which ISMES is presently carrying out.The main purposes of this program are:

• - to collect information on the effectiveness of different excitation methods;

• - to set up the most suitable recording and processing technique;

• - to compare the experimental results with the computed ones, in view of the validation of the adopted computing schemes.

The structure has been excited by a mechanical vibrator delivering sinusoidal forces in a frequency range 2 to 20 cps, in conditions of empty, , and completely full pools. The response, recorded by 36 velocity transducers was digitally processed by means of a Fourier Analyzer. Moreover, a number of Friuli earthquake aftershocks could be picked up, and the building response recorded in many points.More than ten natural frequencies could be detected, and the related damping and mode shapes determined, in a frequency range from 3 to 16 cps.The structure frequencies determined by tests are lower than the computed ones.The energy content of the seismic excitation, due to the large distance from the epicentral area, is confined within very low frequencies. Some data on the behaviour of the RHR and Reactor buildings could however be obtained.The testing technique adopted, which does not require long testing time and high costs, supplies a large amount of reliable data in case of excitation within the linear range. To account for non-linearities, different testing methods should be used, such as blasting or strong forced vibrations of the foundation. Moreover, the adopted method can fully describe the higher vibration modes, which are of noticeable importance as to the behaviour of mechanical and electric equipment installed in the structure.     

Readout system for ground-based tests of BGO calorimeter of DAMPE satellite

A readout system for ground-based tests of the bismuth germanium oxide (BGO) calorimeter of the Dark Matter Particle Explorer satellite is described in this paper.The system mainly consists of a data acquisition board with a field-programmable gate array to implement the control logic,and a graphical user interface software based on LabWindows/CVI.The system has been successfully applied in a series of ground-based environmental experiments and almost all the performance tests throughout the entire manufacturing processes.These contribute significantly to the development of the BGO calorimeter before being submitted for satellite-level integration.