• Tunnel and Underground Space
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• v.24 no.5
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• pp.354-365
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• 2014

The horizontal response spectra using the observed ground motions from 15 Fukuoka earthquake series, including main earthquake (2005/03/20; Mw=6.5), were analysed and then were compared to both the seismic design response spectra (Regulatory Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings (1997). 178 horizontal ground motions, without considering soil types, were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that response spectrum have strong dependency on epicentral distance. The results also showed that the horizontal response spectra revealed higher values for frequency bands at two frequency bands (about 8 - 10 and 16- 20 Hz) than Regulatory Guide 1.60. The results were also compared to the Korean Standard Building Design Spectrum for the 3 different soil types and showed that thehorizontal response spectra revealed higher values for almost all period bands than the Korean Standard Response Spectrum (500 yrs; Return Period; Seismic province 1; SE soil conditions). Through the qualitative improvements and quantitative enhancement of the observed ground motions, the diversity of the observed ground motions should be considered more significantly to improve the certainty of response spectrum.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.279-291
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• 2010

To characterize geological features in study area for high-level radioactive waste disposal research, KAERI (Korea Atomic Energy Research Institute) has been performing the several geological investigations such as geophysical surveys and borehole drilling since 1997. Especially, the KURT (KAERI Underground Research Tunnel) constructed to understand the deep geological environments in 2006. Recently, the deep borehole of 500 m depths was drilled to confirm and validate the geological model at the left research module of the KURT. The objective of this research was to identify the geological structures around KURT using the data obtained from the deep borehole investigation. To achieve the purpose, several geological investigations such as geophysical and borehole fracture surveys were carried out simultaneously. As a result, 7 fracture zones were identified in deep borehole located in the KURT. As one of important parts of site characterization on KURT area, the results will be used to revise the geological model of the study area.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.17-25
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• 2005

Since the safety of nuclear power plant has been becoming a big social issue the exposure dose of radiation for workers has been one of the important factors concerning the safety problem. The existing calculation methods of radiation dose used in the planning of radiation work assume that dose rate does not depend on the location within a work space thus the variation of exposure dose by different work path is not considered. In this study, a modified numerical method was presented to estimate the exposure dose during radiation work in radwaste storage considering the effects of the distance between a worker and sources. And a new numerical algorithm was suggested to search the optimal work path minimizing the exposure dose in pre-defined work space with given radiation sources. Finally, a virtual work simulation program was developed to visualize the exposure dose of radiation doting radiation works in radwaste storage and provide the capability of simulation for work planning. As a numerical example, a test radiation work was simulated under given space and two radiation sources, and the suggested optimal work path was compared with three predefined work paths. The optimal work path obtained in the study could reduce the exposure dose for the given test work. Based on the results, tile developed numerical method and simulation program could be useful tools in the planning of radiation work.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.3
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• pp.257-265
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• 2007

Spent filter wastes of about 1,000 units (200 L) have been stored in the waste storage facility of the Korea Atomic Energy Research Institute since its operation. At the moment, to secure space in a waste storage facility as well as to efficiently manage spent filter wastes, it is necessary to conduct a compaction treatment of these spent filters, and finally, to repack the compacted spent filters into a 200 liter drum. To do that, the spent filter wastes were first classified according to their generation facilities, their generation date and their surface dose rate by investigating the inventory of the spent filters. In order to repack a compacted spent filter in a 200 liter drum, it is first necessary to conduct a radionuclide assessment of a spent filter before compacting it. Therefore, after taking a representative sample from a spent filter without a dismantlement, the nuclide analysis for it will be conducted. And then, after putting a spent filter into a regular drum by conducting the columnar shaping of the hexahedral form of a spent filter, the compaction treatment of the shaped spent filter will be conducted by vertically compacting it.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.213-213
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• 2016

수문조사기기의 검정은 수문조사에 활용할 기기를 일관되고 표준화된 기준으로 검사하여 수문조사에 적합한 기기인지 확인하는 것이다. 이러한 검정은 국가수문자료의 신뢰도를 높이고 유지하는 기본적이고 중요한 업무이다. 검정대상기기는 강수량측정기기, 유속측정기기, 수위측정기기, 부유사측정기기, 토양수분측정기기, 증발산량측정기기로 총 6가지이며, 2009년부터 국토교통부 위탁사업으로 한국건설기술연구원(유량조사사업단)에서 수행하고 있다. 특히 유량조사사업단에서는 유속측정기기를 제외한 나머지 5개 수문조사기기에 대해 검정을 수행하고 있다. 연도별로 2009년부터 2015년까지 98대, 334대, 572대, 539대, 359대, 682대, 690대로 총 3,274대를 검정하였고, 관측기종별로 강수량 1,579대, 수위 1,589대 부유사 23대, 토양수분 33대, 증발산량 50대이다. 신청기관별로는 국토교통부(홍수통제소) 1,847대, 환경부(국립환경과학원) 4대, 한국건설기술연구원(유량조사사업단 포함) 81대, K-water 338대, 한국수력원자력(주) 91대, 일반업체 913대에 대한 검정을 실시하였다. 검정을 실시한 강수량측정기기 1,579대 중 보정없이 합격된 기기는 1,495대, 허용오차기준에 미달되어 보정 실시 후 합격한 기기는 76대이며, 불합격 처리된 기기는 8대이다. 수위측정기기는 합격이 1,586대, 기준에 미달되어 불합격된 기기가 2대로 나타났다. 강수량측정기기의 각 연도대비 통계분석 결과 보정률은 2009년 97대 중 8대(8.2%), 2010년 194대 중 3대(1.5%), 2011년 180대 중 24대(13.3%), 2012년 175대 중 17대(9.7%), 2013년 165대 중 15대(9.1%), 2014년 547대 중 8대(1.5%), 2015년 221대 중 9대(4.1%)로 다소 낮은 수치로 나타났다. 이처럼 보정률이 낮게 나타난 이유는 관할기관의 검정을 위한 유지관리 및 사업자의 사전검사 등을 통해 감소한 것으로 판단되며, 이와 같은 결과는 수문자료의 품질 및 신뢰도 향상으로 이어졌다. 그러나 여전히 선진국에 비해 수문조사기기 검정의 중요성에 대한 인프라 구축이 미흡한 실정이다. 수문조사기기 검정의 선진국이라 할 수 있는 미국의 경우 USGS에서 HIF(Hydrogical Istrumentation Facility)라는 별도 조직을 운영하여 관측기기의 렌탈, 수리, 교정 및 검정, 개발, 교육 등 이러한 작업을 일괄 수행하고 있고 조직 내 자체 시설로 수중펌프 시험소, 자연과 유사한 환경에서 테스트 하는 장소, 대형온도챔버 등을 갖추고 있으며, 이러한 시설을 이용하여 기기의 교정 및 검정, 연구 등을 현장과 비슷한 환경에서 다양한 실험을 통해 검정방법을 비교, 분석하는 것을 볼 수 있다. 현재 우리나라의 수문조사기기는 다양한 방법으로 현장에 설치되어 검정방법의 다양성이 요구된다. 향후 우리나라도 HIF와 같이 다양하고 선진화된 시설과 기술을 개선하고 다각적인 시험 과정을 통해 수준 높은 검정방법체계를 갖추려는 노력이 필요하다.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.285-297
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• 2021

Globally, nuclear-decommissioning facilities have been increased in number, and thereby hundreds of thousands of wastes, such as concrete, soil, and metal, have been generated. For this reason, there have been numerous efforts and researches on the development of technology for volume reduction and recycling of solid radioactive wastes, and this study reviewed and examined thoroughly such previous studies. The waste concrete powder is rehydrated by other processes such as grinding and sintering, and the processes rendered aluminate (C3A), C4AF, C3S, and ��-C2S, which are the significant compounds controlling the hydration reaction of concrete and the compressive strength of the solidified matrix. The review of the previous studies confirmed that waste concretes could be used as recycling cement, but there remain problems with the decreasing strength of solidified matrix due to mingling with aggregates. There have been further efforts to improve the performance of recycling concrete via mixing with reactive agents using industrial by-products, such as blast furnace slag and fly ash. As a result, the compressive strength of the solidified matrix was proved to be enhanced. On the contrary, there have been few kinds of researches on manufacturing recycled concretes using soil wastes. Illite and zeolite in soil waste show the high adsorption capacity on radioactive nuclides, and they can be recycled as solidification agents. If the soil wastes are recycled as much as possible, the volume of wastes generated from the decommissioning of nuclear power plants (NPPs) is not only significantly reduced, but collateral benefits also are received because radioactive wastes are safely disposed of by solidification agents made from such soil wastes. Thus, it is required to study the production of non-sintered cement using clay minerals in soil wastes. This paper reviewed related domestic and foreign researches to consider the sustainable recycling of concrete waste from NPPs as recycling cement and utilizing clay minerals in soil waste to produce unsintered cement.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.31-39
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• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Tunnel and Underground Space
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• v.19 no.1
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• pp.11-18
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• 2009

Use of nuclear energy inevitably brings the problem of radioactive waste disposal. Repositories for disposing radioactive waste use underground space that is unconnected with the outside and the diagonal system, which allows the waste to be deposited. Ventilation if necessary because high-level radioactive waste generates heat. In this study, the air velocity through diagonal branches with regulators of different sizes and in different locations, was measured. The air velocity is determined by the size of the first and last regulators, regardless of the size of other regulators. In the diagonal system. Consequently, once the desired total airflow rate has been achieved by installing the appropriate first and last regulators, the other regulators fan be evenly installed to maintain the minimum air velocity needed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.27-33
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• 2020

Recently, visual object detection and tracking has become a vital role in many different applications. It spans various applications like robotics, video surveillance, and intelligent vehicle navigation. Especially, in current situation where the use of UAVs is expanding widely, detection and tracking to soot down illegal UAVs flying over the sky at airports, nuclear power plants and core facilities is becoming a very important task. The remarkable method in object tracking is correlation filter based tracker like KCF (Kernelized Correlation Filter). But it has problems related to target drift in tracking process for long-term tracking. To mitigate the target drift problem in video surveillance application, we propose a tracking method which uses KCF, adaptive thresholding and Kalman filter. In the experiment, the proposed method was verified by using monochrome video sequences which were obtained in the operational environment of UAV.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.121-130
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• 2018

The KURT (KAERI Underground Research Tunnel) is a research tunnel which is located in KAERI (Korea Atomic Energy Research Institute) site. At KURT, researches on engineering and natural barrier system, which are the most important components for geological disposal system for high level radioactive waste, have been conducted. In this study, we synthesized the site characteristics obtained by various types of site investigation to introduce the geological model for KURT site, and induced the 3-D hydrogeological model for KURT site from the geological model. From the geological investigation at the surface and boreholes, four geological elements such as subsurface weathered zone, upper fractured rock, lower fractured rock and fracture zones were determined for the geological model. In addition, the geometries of these geological elements were also analyzed for the geological model to be three-dimensional. The results from 3-D geological model were used to construct the hydro-geological model for KURT site, which is one of the input data for groundwater flow modeling and safety assessment.