• Korean Journal of Remote Sensing
• /
• v.26 no.5
• /
• pp.571-580
• /
• 2010

Coastal shoreline movement due to erosion and deposition is a major concern for coastal zone management. Shoreline is changed by nature factor or development of coastal. Change of shoreline is threatening marine environment and destroying. Therefore, we need monitoring of shoreline change with time series analysis for coastal zone management. In this study, we analyzed the shoreline change using airphotograph, LiDAR and satellite imagery from 1971 to 2009 in Uljin, Gyeongbuk, Korea. As a result, shoreline near of the nuclear power plant show linear pattern in 1971 and 1980, however the pattern of shoreline is changed after 2000. As a result of long-term monitoring, shoreline pattern near of the nuclear power plant is changed by erosion toward sea. The pattern of shoreline near of KORDI until 2003 is changed due to deposition toward sea, but the new pattern toward land is developed by erosion from 2003 to 2009. The shoreline is changed by many factors. However, we will guess that change of shoreline within study area is due to construction of nuclear power plant. In the future work, we need sedimentary and physical studies.

• Journal of Preventive Medicine and Public Health
• /
• v.33 no.2
• /
• pp.165-173
• /
• 2000

Objectives : To assess the availability of the glycophorin A (GPA) assay to detect the biological effect of ionizing radiation in workers exposed to low-doses of radiation. Methods : Information on confounding factors, such as age and cigarette smoking was obtained on 144 nuclear power plant workers and 32 hospital workers, by a self-administered questionnaire. Information on physical exposure levels was obtained from the registries of radiation exposure monitoring and control at each facility. The GPA mutant assay was performed using the BR6 method with modification by using a FACScan flow cytometer. Results : As confounders, age and cigarette smoking habits showed increasing trends with GPA variants, but these were of no statistical significance. Hospital workers showed a higher frequency of the GPA variant than nuclear power plant workers in terms of the NO variant. Significant dose-response relationships were obtained from in simple and multiple linear regression models. The slope of the regression equation for nuclear power plant workers was much smaller than that of hospital workers. These findings suggest that there may be apparent dose-rate effects. Conclusion : In population exposed to chronic low-dose radiation, the GPA assay has a potential to be used as an effective biologic marker for assessing the bone marrow cumulative exposure dose.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.12
• /
• pp.561-568
• /
• 2013

Instrumentation and control system in nuclear power plant performs protecting, controling and monitoring safety operation of Nuclear Power Plant. As cyber attack to the control equipment of instrumentation and control system can cause reactor shutdown and radiation release, it is required to design the instrumentation and control system considering cyber security in accordance with regulatory guides and industrial standards. In this paper, we proposed a design method of uni-directional communication structure which is required in the design of defense-in-depth model according to regulatory guides and industrial standards and we implemented a communication board with the proposed method. This communication board was tested in various test environments and test items and we concluded it can provide uni-directional communication structure required to design of defense-in-depth model against cyber attack by analyzing the results. The proposed method and implemented communication board were applied in the design of SMART (system-integrated modular advanced reactor) I&C (instrumentation and control) systems.

• Journal of Radiation Protection and Research
• /
• v.47 no.1
• /
• pp.30-38
• /
• 2022

Background: Residential areas have some factors on the external exposure of residents, who usually spend a long time in these areas. Although various survey has been carried out by the government or the research institutions after the Fukushima Daiichi Nuclear Power Plant accident, the mechanism of radiocesium inventory in the terrestrial zone has not been cleared. To better evaluate the radiation environment, this study investigated the temporal changes in air dose rate and ¹³⁷Cs inventories (Bq/m²) in residential areas and agricultural fields. Materials and Methods: Air dose rate and ¹³⁷Cs inventories were investigated in residential areas located in an evacuation zone at 5-8 km from the Fukushima Daiichi Nuclear Power Plant. From December 2014 to September 2018, the air dose rate distribution was investigated through a walking survey (backpack survey), which was conducted by operators carrying a γ-ray detector on their backs. Additionally, from December 2014 to January 2021, the ¹³⁷Cs inventories on paved and permeable grounds were also measured using a portable γ-ray detector. Results and Discussion: In the areas where decontamination was not performed, the air dose rate decreased faster in residential areas than in agricultural fields. Moreover, the ¹³⁷Cs inventory on paved surfaces decreased with time owing to the horizontal wash-off, while the ¹³⁷Cs inventory on permeable surfaces decreased dramatically owing to the decontamination activities. Conclusion: These findings suggest that the horizontal wash-off of ¹³⁷Cs on paved surfaces facilitated the air dose rate decrease in residential areas to a greater extent compared with agricultural fields, in which the air dose rate decreased because of the vertical migration of ¹³⁷Cs. Results of this study can explain the faster environmental restoration in a residential environment reported by previous studies.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.96.4-96
• /
• 2002

Thermal infrared imaging is a highly promising technology for condition monitoring and predictive maintenance of electronic, electrical and mechanical elements in nuclear power plants. However, conventional low-cost infrared imaging systems suffer from poor spatial resolution compared to commercial CCD cameras. This paper describes an approach to enhance inspection performances for calandria reactor area of Wolsung nuclear power plant through the technique of superimposing thermal infrared image into real CCD image. In the occurrence of thermal abnormalities on observation points and areas of calandria reactor area, unusual hot image taken from thermal infrared camera is mapped upon re...

• Journal of the Korean Society for Nondestructive Testing
• /
• v.27 no.6
• /
• pp.509-519
• /
• 2007

This paper presents new techniques under development for monitoring the health and vibration of the active components in nuclear power plants, The purpose of this study is to develop an automated system for condition classification of a check valve one of the components being used extensively in a safety system of a nuclear power plant. Acoustic emission testing for a check valve under controlled flow loop conditions was performed to detect and evaluate disc movement for valve failure such as wear and leakage due to foreign object interference in a check valve, It is clearly demonstrated that the evaluation of different types of failure types such as disc wear and check valve leakage were successful by systematically analyzing the characteristics of various AE parameters, It is also shown that the leak size can be determined with an artificial neural network.

• Proceedings of the KIEE Conference
• /
• 2000.11d
• /
• pp.663-665
• /
• 2000

For the control system of thermal turbine in fuel and nuclear power plant, as high reliability and availability are required, redundant control system is generally applied. This paper presents the configuration and design of such a redundant control system that can be suitable for control and monitoring of the turbine. System components such as I/O system, communication networks, voting system are designed, and especially the new intelligent voter using serial communication are proposed. The characteristics of the implemented control system is independence of the control, protection and monitoring functions, and discrimination of the redundancies, and high availability. The control functions such as speed control, load control, valve control and protective functions such as overspeed and PLU are designed in detail.

• Journal of the Korean Society of Safety
• /
• v.30 no.5
• /
• pp.123-130
• /
• 2015

Wolsong Unit 2,3&4 has been performing a containment integrity test during power operation. This test could impact to the safe operation during test. If an accident occurs during pressure dropping phase, reactor trip can be delayed because of the increased pressure difference which causes a time delay to reach the trip set-point. On the contrary, if an accident occurs during pressure increasing phase, reactor trip could be accelerated because the pressure difference to the trip set-point decrease. Point Lepreau nuclear power plant, which installed GCLMS (Gross Containment Leakage Monitoring System) in 1990, has discontinued the test since 1992 due to these adverse effects. Therefore, we evaluated the risk to obviate the GCLMS test based on PWR's ILRT (Integrated Leak Rate Test) extension methodologies. The results demonstrate that risk increase rate is not high in case of performing only ILRT test at every 5 years instead of doing GCLMS test at every 1.5 years. In addition, the result shows that GCLMS test can be removed on a risk-informed perspective since risk increasement is in acceptable area of regulatory acceptance criteria.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1372-1375
• /
• 1996

In this paper, we developed and ERMS, which monitors radiation continuously in the vicinity of the nuclear power plant not only to intend health and security of the adjacent residents but also to prevent environmental pollution. Especially, applying digital DCU and SCA which are easy to control and accurate, we obtained good results.

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.647-650
• /
• 1998

본 논문에서는 원자로의 몸통부위와 상,하부 헤드에 존재하는 금속파편에 의한 충격위치 예측을 위한 알고리즘에 금속파편의 질량을 동시에 판별하는 프로그램을 접목시켜 금속파편의 충격위치와 질량을 동시에 판별할 수 있는 통합 환경 LPMS(loose parts monitoring system)에 관한 연구를 수행하였다. 또한 모의실험을 통하여 본 연구에서 제안된 통합 환경 LPMS 알고리즘이 금속파편의 위치와 질량 예측을 함에 있어서 우수한 성능을 보임을 확인하였다.