• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.241-245
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• 2006

In the examination of Steam Generator (SG) tube in Nuclear Power Plant (NPP) Eddy Current Testing (ECT) probes play an Important role in detecting the defects. Bobbin probe and Rotating Pancake Coil (RPC) probe is usually used for the inspection of SG tube. Bobbin probe is good at high speed inspection, but ability of detection of circumferential defect is very weak. On the contrary RPC probe, which moves for inspection in the direction of axial and circumferential simultaneously, has very slow inspection speed, but it was excellent detection capability fur small cracks, which is hardly detected by bobbin probe. Many examinations of SG tube examination of NPP are achieved during short period. Therefore, solution about this must develop probe of new form for examination performance and examination time shortening of other probe. In this paper, analyzed technological present condition of Bob-bin probe and RPC probe been using in Nondestructive Testing (NDT) for SG tube defect detection and Appeared about background theory and view of developed probe newly.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.212-218
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• 2000

The importance and role of pre-/in-service inspection(PSI/ISI) for nuclear power plant(NPP) components are intimately related to plant design, safety, reliability, operation, etc. In this paper, for an effective and efficient management of large amounts of PSI/ISI data in NPPs, an intelligent database program(WS-IDPIN) for PSI/ISI data management of NPP was developed. WS-IDPIN program enables the prompt extraction of previously conducted PSI/ISI conditions and results so that the time-consuming data management, painstaking data processing and analysis in the past are avoided. Furthermore, development of ISI UT auto flaw evaluation and acceptance module based on ASME Code Sec. XI were presented. This module can be used for any angle beam examination from flat plate to spherical shapes as selected by the proper azimuthal angle. This program can be further developed as a unique PSI/ISI data management expert system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.883-888
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• 2016

We investigated fish species composition seasonally at the intake and discharge of Weolseong Nuclear Power Plant (WS-NPP) from February to November 2008 using a trammel net. At the intake, 121 individuals belonging to 28 species were collected, and 157 fish from 34 species were sampled at the WS-NPP discharge. Dominant species at the intake were Chelidonichthys spinosus (17.2%), Scomber japonicus (11.5%) and Ditrema temminckii (8.2%) at the intake, while Sillago japonica (18.5%), Chelidonichthys spinosus (13.4%) and Konosirus punctatus (8.3%) dominated at the discharge. The species count and diversity index at the discharge were highest during winter, whereas those at the intake were highest during spring, perhaps due to warm seawater at the discharge site. This study is the first to reveal an effect of effluent water on the aggregation of warm water fish species during winter.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.546-550
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• 1996

The personal-computer software program named SAMS(Structural Aging Management System) was developed for the concrete structure of NPP(Nuclear Power Plant). SAMS is constituted of three part, detabase system containing various inspection data, operation program for standard input/output of the inspection data, and application program for efficient operation of database system. Using the SAMS, the field engineers can easily acquire the information about the various inspection data, repair and accidental histories of NPP structures. SAMS will contribute to the effcient maintenance of NPP structures.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.707-716
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• 2023

The influence of waste technological waters of thermal and fast reactors of Beloyarsk NPP (Russia) on the accumulation of ⁶⁰Co, ⁹⁰Sr and ¹³⁷Cs in macrophytes and ichthyofauna of the cooling pond has been studied. Critical radionuclides, routes of their entry into the ecosystem and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at the Beloyarsk NPP, based on fast reactors, has a much smaller effect on the release of artificial radionuclides into the environment. Therefore, during the entire period of monitoring studies (1976-2019), the decrease in the specific activity of radionuclides of NPP origin in macrophytes was 13-25800 times, in ichthyofauna 1.5-44.5 times. The maximum discharge of artificial radionuclides into the Beloyarsk reservoir was noted during the period of restoration and decontamination work aimed at eliminating the emergencies at the AMB reactors of NPP. The factors influencing the accumulation of artificial radionuclides in the components of the freshwater ecosystem of the Beloyarsk cooling pond have been determined, including: the physicochemical nature of radioisotopes, their concentration in surface water, the temperature of the aquatic environment, the trophicity of the reservoir, the species of hydrobionts.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3694-3703
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• 2021

Instrumentation and Control systems (I&C) play a significant role in nuclear power plants (NPP) and other safety critical systems (SCS). We have conducted a rigorous study and discussions with experienced practitioners worldwide the strategy for the development of I&C systems to investigate the several aspects related to their dependability. We discussed with experienced practitioners that work on nuclear domain with the intention of knowing their approach, they use day-to-day for the development of such systems. The aim of this research is to obtain to provide guidance to those building I&C systems of NPP and have implications on state engineering licensure boards, in the determination of legal liability, and in risk assessment for policymakers, corporate governors, and insurance executives.

• Journal of Internet of Things and Convergence
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• v.6 no.1
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• pp.73-81
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• 2020

The internet of things (IoT) using cloud computing is applied to nuclear industry in which the nuclear power plant (NPP) accident is analyzed for the safety assessment. The Fukushima NPP accident is modeled for the accident simulations where the earthquake induced plant failure accident is used for analyzing the cloud computing technology. The fast and reasonable treatment in the natural disaster was needed in the case of the Fukushima. The real time safety assessment (RTSA) and the Monte-Carlo real time assessment (MCRTA) are constructed. This cloud computing could give the practicable method to prepare for the future similar accident.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1248-1252
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• 2014

In this study, we designed a signal processing module using a radiation hardened technology that can be applied to the all measurement sensors inside nuclear power plant containment. Also, for verification that it can be used for high-level radiation environment (Harsh environmental zone inside containment of NPP), we carried out evaluation tests for a designed module using a $Co^{60}$ gamma-ray source up to 12 kGy(Si). And, we had checked radiation hardening level that it has been satisfied up to 12 kGy(Si).

• Nuclear Engineering and Technology
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• v.28 no.3
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• pp.290-298
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• 1996

Direct Containment Heating, DCH, is supposed to occur during a core melt-down accident if the primary system pressure is still high at the time of vessel breach in a Nuclear Power Plant (NPP). In this case, DCH is considered to be one of very important severe phenomena during postulated severe accident scenario because of the fast heat transfer rate to atmosphere and the sharp pressure increase in a containment. To reduce the effect of this DCH phenomena, the capture volume wes designed at Ulchin NPP units 3 and 4. But, the effect of this has not been studied extensively. This work consists of experimental and numerical analyses of the effects of capture volume in the cavity on DCH phenomena. The experimental model is a 1/30 scaled-down model of Ulchin NPP units 3 and 4. We used three types of capture volumes to investigate the effect of size. Numerical analysis using CONTAIN 1.2 is performed with the correlation for the dispersed fraction of molten corium from the cavity into the containment derived from the experimental data to examine the effect of capture volume on DCH phenomena in full scale of Ulchin NPP units 3 and 4.

• Journal of Radiation Protection and Research
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• v.39 no.1
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• pp.14-20
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• 2014

A lot of radiation exposure for radiation workers who are engaged in Nuclear Power Plants, especially PWRs, have been caused during the outage by CRUD, such as $^{58}Co$, $^{60}Co$, in Reactor Coolant System. And therefore we need to know source terms to achieve optimization of protection for the radiation workers from radiation exposure at Nuclear Power Plants efficiently. This study analyzed source terms at domestic NPPs (PWRs) nearby Steam Generator with CZT semiconductor detector using by IN-VIVO method during the outage for the first time in the country. We checked difference for the detected source terms between old and new NPP. It was performed especially to see a change of source terms by water chemistry process as well. There was not any difference by water chemistry process both NPPs. The main source terms are $^{58}Co$ and $^{60}Co$ at all NPPs. $^{59}Fe$ only appears in the new NPP. $^{137}Cs$ and $^{95}Zr$ are shown in the old NPP. The fraction of $^{58}Co/^{60}Co$ in the new NPP is higher than the old NPP for increasing the specific activity of $^{60}Co$.