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[en] For the design of the core power control in KALIMER (Korea Advanced LIquid MEtal Reactor), the control characteristics in a system with a long response delay time were investigated using a simplified model that easily and clearly represents the relationship among the delay time, control logic and response. Based on the investigation results, basic control algorithm was set up and also it was found that the core exit temperature performs much better than the core inlet temperature does as a control measurement parameter. Applying the findings in the simplified model investigation, the control logics and parameter constants were preliminarily determined for KALIMER. The performance of the preliminarily determined logics and values was evaluated for various plant operation transients under the categories of the turbine leading and reactor leading modes and refined. The evaluation results showed that the KALIMER system is satisfactorily controlled. From this, the controllability of the KALIMER system design was confirmed
[en] In nuclear power plants, nondestructive examinations(NDE) plays an important role in ensuring the integrity and reliability operation. As the number of plants and operational time increased, manual handling of voluminous data associated with PSI/ISI(preservice/inservice inspection) could result in many errors or mistakes in writing the examination plan or other reports. Several new approaches to process the data have been attempted and DBMS(Data Base Management System) has been well known concept with a faster and more accurate data processing. This paper proposes an application program, called NDTSYS designed with DBMS in micro computer. The program could be used for a tool to add new records to a data base, change existing records, delete records and request reports with the data base. It would be helpful to the user who manage the PSI/ISI data with minimal time and effort
[en] The purpose of applying the Technology Readiness Level/Design Readiness Level (TRL/DRL) in technical risk management is to make technology assessments, and improve communication among researchers with a consistent, systematic technology readiness Technical risk management for the Nuclear Hydrogen Production project was adopted of experience assessed with Delphi Method from the Next Generation Nuclear Plant(NGNP)of the DOE to improve the poor contactor management of the major projects which experienced cost increases and/or schedule delays in long-term. In the current phase that is doing key technology research and development projects, the technology readiness level was reviewed and applied to the Nuclear Hydrogen Production project to prepare an input for the next design phases. Based on the previous works, pre-conceptional design and key R and D works for the Nuclear Hydrogen Design and Development(NHDD) projects and the results of key research and development projects, the TRL was applied to assess the levels and compared with the advanced design stages of Westinghouse Electric Co. With this process, several issues were identified to apply the design and technology level to the familiar steps of design process and research and development projects. In order to resolve these issues, it is needed to systematically adjust and modify the current process with TRLs
[en] EFD(Early Fault Detection) system is the modelbased fault detection system, it divides target plant for diagnosis into several subprocess presented with mathematical model. Each subprocess receives process data from plant, and calculates error-free process variable from the mathematical model. Also EFD system retrieves real plant variable periodically, and compares it with the error-free process variable. When the deviation between the calculated error-free value and the real plant variable is detected, EFD alarm is generated. EFD system is implemented with FORTRAN in Halden Reactor Project in the late 1980s. Recently EFD system is reimplemented with COAST(COmputerized Alarm System Toolbox) to build IDS(Integrated Diagnosis System). In this paper, the concept of IDS and EFD, and the result of the implemented EFD with COAST is described
[en] The top design concept of Instrumentation and Control (I and C) systems for Korea Advanced Liquid Metal Reactor(KALIMER) is to apply the modern digital technology and to achieve high reliability and safety in I and C systems. This paper describes the basic structure of I and C systems developed during the conceptual design stage of KALIMER. The fully digitalized I and C systems have the structure of four levels such as a human system interface level, supervisor and manager level, distributed control and protection level, and sensor and actuator level. This paper describes the functional goals for the KALIMER I and C systems and the design bases for each I and C system
[en] The electrical properties of SrCe0.95Eu0.05O3-δ were studied as a function of both oxygen partial pressure and water vapor partial pressure in the temperature range of 500-800 C, and the partial conductivities of protons, holes, and oxygen vacancies were calculated from the proposed defect model. P-type conduction was dominant in an oxidative atmosphere. It was shown that, in a wet atmosphere, SrCe0.95Eu0.05O3-δ is a mixed conductor of protons, holes, and oxygen ions. A conduction transition from protons to holes and/or oxygen ions was found as temperature increased. The calculated activation energy of oxygen ion transport was 0.67 eV; standard solution enthalpy of water dissolution was -164 kJ/mole, which is larger than that of SrCe0.95Eu0.05O3-δ. The effect of dopants on the conduction mechanism is explained by a hopping mechanism.
[en] The I and C systems and control rooms of nuclear power plants have been constructed by using the automatic control concept and changed to computer-based systems in nowadays. For Increase of an automation and CRT, the role of operators is changed to monitor the condition of the nuclear power plants. Therefore, the information that is offered to operators has to integrate in order for operator to understand the hole condition of plants. In commercial nuclear plants, raw data of sensors and components are shown in a control room. So, operators can not diagnose the condition of plants correctly. For a development of an integrated operator aid system which contain an alarm processing system and a fault diagnosis system, we integrated IGENPRO of ANL(Argonne National Lab.) and ADIOS of KAERI (Korea Atomic Energy Institute). IGENPRO is a fault diagnosis system contains three module such as PROTREN, PRODIAG and PROTREN. ADIOS is an alarm processing system that informs operators of important alarms. The integrated operator advisory support system developed in the research is composed of an alarm processing module and a fault diagnosis module. The alarm processing module shows important alarms to operator by using dynamic alarm filtering methods. The fault diagnosis module shows the cause of faults of sensors and hardwares
[en] Ultrasonic pattern recognition is the most effective approach to the problem of discriminating types of flaws in weldments based on ultrasonic flaw signals. In spite of significant progress in the research on this methodology, it has not been widely used in many practical ultrasonic inspections of weldments in industry. Hence, for the convenient application of this approach in many practical situations, we develop an intelligent ultrasonic signature classification software which can discriminate types of flaws in weldments based on their ultrasonic signals using various tools in artificial intelligence such as neural networks. This software shows the excellent performance in an experimental problem where flaws in weldments are classified into two categories of cracks and non-cracks. This performance demonstrates the high possibility of this software as a practical tool for ultrasonic flaw classification in weldments
[en] Automatic on-line surface inspection systems have been applied for monitoring a quality of steel strip surfaces. One of the important issues in this application is the performance of on-line defect classifiers. Rule-based classification table methods which are conventionally used for this purpose have been suffered from their low performances. In this work, probabilistic neural networks and the enhanced classification tables which are newly proposed here are applied as alternative on-line classifiers to identify types of surface defects on cold rolled strips. Probabilistic neural networks have shown very excellent performance for classification of surface defects
[en] In the present study, using eddy current technique (ECT), we explored two kinds of defects commonly found in railroad monitoring. The first one is cracks initiated on the surface of rail head which slowly progresses into vertical rail plane, the second one is squat type of defects grown on the running head surface. A reliable ECT system equipped with plus point ECT probe was developed and experiments were conducted on a 10 mm thick medium carbon steel plate with two kinds of machined defects varying on their dimensions. An optimized plus point probe was fabricated for the experimental purpose and a Lab VIEW based program was developed to interactively collect and analyze the obtained data. Predefined defects (slit, squat) with changing defect depth and length for both the cases machined on S45C medium carbon steel plate were examined. Prior to the experiments, simulation studies were conducted to fully understand the defect dimensions and optimized the experimental parameters. Response signal parameters, amplitude and phase were analyzed to characterize the defect features. The designed system shows better performance to detect the deepest defect up to 5 mm approximately, and it can be extended further with moderate signal to noise ratio. Two kinds of defects can be categorized according to the obtained signals.