[en] This paper describes three kinds of efforts for the development of PSA workstation in KAERI; Development of a PSA tool, KIRAP, Reliability Database Development, Living PSA tool development. Korea has 9 nuclear power plants (NPPs) in operation and 9 NPPs under design or construction. For the NPPs recently constructed or designed, the probabilistic safety assessments (PSAs) have been performed by the Government requirements. For these PSAs, the MSDOS version of KIRAP has been used. For the consistent data management and the easiness of information handling needed in PSA, APSA workstation, KIRAP-Win is under development under Windows environment. For the reliability database on component failure rate, human error rate, and common cause failure rate, data used in international PSA or reliability data handbook are collected and processed to use in Korean new plants' PSAs. Finally, an effort for the development of a living PSA tool in KAERI based on dynamic PSA concept is described

[en] Ο The main purpose of administrative report of an organization is to deliver a critical mind about surrounding circumstance and rational alternatives to a final decision maker Ο An established report system with unified formality and systematic concept playes critical role to make right decision and efficient review about pending issues Ο By understanding current situation of report system using in KAERI and analysing examples of other organization, we established specific administrative report writing guideline for KAERI Ο We expect efficient communication and increasing productivity from the guideline by establishing and diffusing administrative report common writing guideline reflecting longstanding administrative experience and know-how of a specialized committeeman of KAERI

[en] Progress of the hard-wired instrumentation and control works for the neutral beam test stand(NB-TS) has been existed for the past one year period. Details of the installed arc detector circuit are explained. LN₂ level and temperature control during the cryosorption pumping operation are explained with an emphasis on its control circuit. With an expectation of more accurate and sensitive measurement of temperatures than the thermocouple utilization during the calorimeter operation, PT-100 resistance temperature detector(RTD) utilization is initiated and the results are described. During the ion beam experiment, physical measurements are made with some delayed time than the beam extraction, and thus a delayed trigger pulse generator was fabricated and installed to the system. Underlying principles of the electronic circuits for the interlock implementation and optical signal transmission are introduced. These are basically the application of operational amplifier circuits. A cautious aspect of the SMPS(switch mode power supply) utilization is also give

[en] A data collection worksheet and guideline to collect HRA (Human Reliability Analysis) data with simulator data sources were developed for the HRA data handbook project by KAERI. Using the data worksheet, simulator data were collected and analyzed for an HRA qualitative database. The purpose of this paper is to define the causalities of operators' UAs (Unsafe Acts) ending in an inappropriate component manipulation and recovery during an EOP (Emergency Operating Procedure) operation, and to show some results for the causality from a case study. The reason we suggest the causality of an UA is because an inappropriate manipulation during an EOP operation can be resulted by the causality among operators in an MCR (Main Control Room). Therefore, a 'causality' data field was inserted into the data worksheet to identify the real initiator, and related operators for an inappropriate component manipulation. With this 'causality' data field, an HRA analyzer can establish who caused an UA (or a recovery) and who was involved in the process. They can also calculate the HEP (Human Error Probability) grouped by the initiator if they are interested in the HEP by the initiator

[en] The global market of Container Inspection System (CIS) is worth of a few billions dollar whereas a small number of companies such as Varian, Rapiscan in U.S.A, Nuctech in China, etc. has dominated the CIS market. The prices of CIS equipment are up to 10 millions dollar and also fairly huge amount of maintenance costs are required. Korea customs has fourteen CISs at major ports and borderline in Busan, Incheon, etc. In order to improve the national competitiveness and reduce outflow of foreign currency, Korea Atomic Energy Research Institute (KAERI) has started to develop localized CIS. In this study the relationship between CMS velocity and image optimization was experimentally confirmed. Images are acquired at 70 Hz currently, but optimized parameters which include CMS velocity will be derived through further experiments with different frequency to get the best image qualities in the future.

[en] The chimney of the air-cooled RCCS is too high to perform a full scale-test, so a reduced-scale test is necessary to verify its performance. Since the radiation is independent of the scale effect and the convection is dependent, there is no scaling methodology satisfying similarities in both radiation and convection. The test matrix for the comparative study was focused on the scale effect of the heated riser height. Comparison with the test results and the post-test analysis results showed that the mixed convection in the riser duct and the radiation similarity were very important to estimate the scale effect. It is recommended that the buoyancy number based on the heat flux is used to consider the mixed convection effect for the air cooled RCCS scaling law. The improved scaling law can be applied to demonstrate the passive safety of the air-cooled RCCS.

[en] The purposes of the study are: to implement obligations specified in treaties and domestic laws and to enhance the nuclear transparency suffered from a careless past experiments with a nuclear material; and to prepare nuclear emergency and to settle down effectively the emergency situation. In the second year (2007) the project focuses on the development of two systems: an information treatment system that controls and manages the nuclear material in facilities at KAERI; and a real-time surveillance system that integrates the safety system information of nuclear facilities in KAERI. The information treatment system for IAEA safeguards and facility-level accountancy was developed by October 2007 and tested afterwards. Collection system of safety parameters such as data base server system installation and operation was improved to enhance the stability of the safety information surveillance system in KAERI nuclear facilities. An early recognition and notice system to the related persons at the occurrence of abnormal status of nuclear facilities was established. Also, an alarm system, which can display the status of the facilities' safety system parameters and can retrace the history of alarms, has been established in the surveillance system

[en] The primary objectives of the physical protection are to protect nuclear material from theft and unauthorized removal and to prevent the sabotage of nuclear material and facilities. To accomplish the objectives, a system for the physical protection (PPS) of nuclear material and facilities should be established and implemented under the 'Law for physical protection and measures against radiological emergency' and the recommendations INFCIRC/225 /Rev.4, which are considered as a baseline for the PPS. The current PPS of KAERI including the physical protection elements such as detection, delay and access control was reviewed and analyzed. The options for upgrading the PPS were suggested to meet the domestic and international obligations. An upgrade plan chosen by KAERI is being established

[en] To implement obligations under the Non-Proliferation Treaty (NPT) and the bilateral agreements more effectively, we proposed a computerized system named the Nuclear Control and Management Information Treatment System (NCAMITS) as a part of the Nuclear Transparency Enhancement Project at the Korea Atomic Energy Research Institute (KAERI). The database system is designed not only to undertake the facility-level accounting for and control of nuclear material at KAERI, but also to meet the requirements of the State (National) System of Accounting and Control (SSAC). Since the NCAMITS will provide services for the facility operators as well as the safeguard information managers at KAERI, the development of the system is supposed to accommodate the end-user's convenience and the manager's sophisticated specifications as well

[en] A modeling and simulation methodology was proposed in order to implement the dynamic material flow of the pyroprocess. Since the static mass balance provides the limited information on the material flow, it is hard to predict dynamic behavior according to event. Therefore, a discrete event system (DES)-based model named, PyroFlow, was developed at the Korea Atomic Energy Research Institute (KAERI). PyroFlow is able to calculate dynamic mass balance and also show various dynamic operational results in real time. By using PyroFlow, it is easy to rapidly predict unforeseeable results, such as throughput in unit process, accumulated product in buffer and operation status. As preliminary simulations, bottleneck analyses in the pyroprocess were carried out and consequently it was presented that operation strategy had influence on the productivity of the pyroprocess.