[en] As the instrumentation and control (I and C) equipment suppliers tend to provide digital components rather than conventional analog type components for instrumentation and control systems of nuclear power plants(NPPs), it is unavoidable to adopt digital equipment for safety I and C systems as well as non-safety systems. However, the full introduction of digital equipment for I and C systems of nuclear power plants raises several concerns which have not been considered in conventional analog I and C equipment. The two major examples of the issues of digital systems are environmental/electromagnetic compatibility (EMC) and software reliability. This report presents the survey and research results on environmental and electromagnetic effect on I and C equipment of nuclear power plants to give a guideline for aging management and design process. Electromagnetic site surveys were conducted to be used as a part of technical basis to demonstrate that I and C systems are compatible with the ambient electromagnetic noise in Korean nuclear power plants

[en] The reactor protection system (RPS) plays the roles of generating the reactor trip signal and the engineered safety features (ESF) actuation signal when the monitored plant processes reach the predefined limits. A Korean project group is developing a new digitalized RPS and the Cabinet Operator Module (COM) of the RPS is used for the RPS integrity testing and monitoring by an equipment operator. A flat panel display (FPD) with a touch screen capability is provided as a main user interface for the RPS operation. To support the RPS COM user interface design, actually the FPD screen design, we developed a user interface style guide because the system designer could not properly deal with the many general human factors design guidelines. To develop the user interface style guide, various design guideline gatherings, a walk-though with a video recorder, guideline selection with respect to user interface design elements, determination of the properties of the design elements, discussion with system designers, and a conversion of the properties into the screen design were carried out. This paper describes the process details and the findings in the course of the style guide development. (Author)

[en] This report describes a comparison result of technical standards applied to instrumentation and control systems for nuclear power plants between in Korea and in Russia. Russia also has a state-run organization authorized to conduct approval, cancellation, and audit in use of nuclear facility or equipment. The Russian standards for nuclear instrumentation and control equipment are analogous with the Korean ones in the aspect of basic concepts and principles. However, there are some differences in document structure, design requirements, qualification test items, depth of contents between two standard systems. The biggest deviation exists in the standard documents for seismic qualification and electromagnetic interference qualification. Korean seismic qualification standard utilizing US approach, defines testing and qualification methods specifically and clearly. Russian standards however provide only conceptual definitions and requirements in the seismic related aspects. Therefore, it is conceived that any equipment or system qualified seismically in accordance with Korean standards should additionally provide technical evidence that it is satisfactory with Russian standards as well. In electromagnetic interference qualification, because Russian standard requires more testing items than the current Korean standard, the additional qualification tests are necessary to meet the Russian requirements. However, these additional test items are based on IEC(International Electrotechnical Commission), therefore it is not a problem to perform those tests in a Korean testing facility

[en] The Project has for several years worked in the field of alarm handling. COAST (COmputerised Alarm System Toolbox) was developed based on long experience with several different methods for identification of plant status and detection of plant anomalies. The first version was released in 1995, and this report describes the new features which have been added to COAST, as well as its main advantages. A Windows NT version is made, and the COAST editor is re-implemented in Java. Some pros and cons about the Java language in making an editor are included. Early Fault Detection alarms are implemented in COAST, serving as input to the Integrated Diagnosis System. The COAST implementation is described in this report, as an example of how to make such model-based surveillance systems. (author)

[en] Analog type I and C Systems of Nuclear Power Plants are being replaced by digital type systems because of the aging problems of the I and C systems. New NPPs have adopted computer-based digital I and C systems because the economical efficiency and the usability of the systems become higher than the analog I and C systems. However, the digital I and C systems have not been applied to NPPs because the reliability of computer systems and software has not been validated. The research works for reliability of the systems have been performed in many institutions. In this study, we reviewed the current status of I and C systems for advanced NPPs that have developed in Korea as well as in other countries until this year. We hope to use the result of this study to plan for a localization of NPP I and C systems. In this study, the I and C systems of advanced reactors such as AP600 and NUPLEX 80+ of U.S.A, CANDU 9 of Canada, APWRs and ABWRs of Japan, N4 of France, and KNGR, KALIMER, and SMART of Korea were reviewed. We reviewed the nuclear policy of U.S.A and Europe, and the NPP digital I and C systems developed in many international research institutes. Using this result, we extracted items to be researched and classified those by types of reactors. Then, we established the localization method of NPP digital I and C systems

[en] The CNS(Compact Nuclear Simulator) has been using for the operation training and the function evaluation of the nuclear power for control system plant. The modeling code of the CNS is operating on the HP Unix Operation System(OS). As the HP Unix Operation System(OS) is upgraded, application programs developed on lower version of OS did not work well. In this project, the application program is changed to work in the upgrade version of OS, and the software obsolescence is resolved. Also GUI(Graphic User Interface) for the instructor is developed

[en] Objectives of Project - Development of Digital Safety Grade PLC and Licensing - Development of Safety System(RPS) and Licensing - Development of Safety System(ESF-CCS) and Licensing Content and Result of Project - POSAFE-Q PLC : Development of PLC platform for Shin-UCN unit 1 and 2 ·Development Scope : Processor module, Power module, 3 kinds of Communication module, Bus extension module(Master and Slave), 16 kinds of Input and Output module ·PLC application software development tool(pSET) - IDiPS RPS and IDiPS ESF-CCS : Development of PPS for Sin-UCN 1 and 2 ·Development Scope - 4-channels RPS with the KNICS inherent architecture - A part of 1-channels ESF-CCS with the KNICS inherent architecture - Licensing ·optical Report Submitted and Expected to finish the licensing process until Aug. 2008

[en] The natural convective flows on outer sphere rise along surface. At top of sphere, the flows are lifted-up plume shape. For laminar flows, the local heat transfer shows maximum at the bottom of sphere and a monotonic decreases as flows approached to the top. The laminar natural convection heat transfer on a single sphere has been studied experimentally and numerically by several researchers. However, relatively less study has been performed for turbulent flows as it requires large facilities to achieve high Rayleigh numbers. The flows, which occur transition, is hard to experiment because of unstable. This study tried measurement of heat transfer and visualization external natural convection on a single sphere. The basic idea is that the plating patterns of copper on the sphere in mass transfer system will reveal the amount of heat transfer according to angular distance from the bottom. This study simulated natural convection on a single sphere and performed a mass transfer experiment using heat and mass transfer analogy concept. For visualization experiment, streak form plating pattern was observed. In this case, it seems that turbulence sets on the top of sphere and increases local heat transfer.

[en] Highlights: • We develop a modified FMEA analysis suited for applying to software architecture. • A template for failure modes on a specific software language is established. • A detailed-level software FMEA analysis on nuclear safety software is presented. - Abstract: A method of a software safety analysis is described in this paper for safety-related application software. The target software system is a software code installed at an Automatic Test and Interface Processor (ATIP) in a digital reactor protection system (DRPS). For the ATIP software safety analysis, at first, an overall safety or hazard analysis is performed over the software architecture and modules, and then a detailed safety analysis based on the software FMEA (Failure Modes and Effect Analysis) method is applied to the ATIP program. For an efficient analysis, the software FMEA analysis is carried out based on the so-called failure-mode template extracted from the function blocks used in the function block diagram (FBD) for the ATIP software. The software safety analysis by the software FMEA analysis, being applied to the ATIP software code, which has been integrated and passed through a very rigorous system test procedure, is proven to be able to provide very valuable results (i.e., software defects) that could not be identified during various system tests

[en] The existing studies assumed that if the fluid mixing exists at the downstream on the sphere nearly perfect, the heated sphere can simulate the conditions of all heated sphere in packed beds. While, most of the studies for packed beds heat transfer in forced convection were carried out numerically for all heated spheres. However, numerical study is limitary since numerical method is difficult to simulate random packed beds. This paper was experimentally studied in two parts: first, the forced convective heat transfer from single heated sphere varying Red and second, the all heated sphere in packed beds varying the height of packed beds and Red. This paper is to discuss the experiments results of heat transfer varying positions of a single heated sphere in unheated packed beds, and compare the single sphere correlation with all heated sphere in packed beds. For single heated sphere in packed bed case, the single heated sphere in packed beds show good agreements with the correlation of Achenbach where the Pr not act as parameter. This seems that the properties do not affect the heat transfer. For all heated sphere in packed beds, the heat transfer decreases when the height of packed beds increase. This seems to the preheating increase when the height of packed beds increase.