• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2004.04a
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• pp.123-140
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• 2004

저준위 방사성폐기물 안전성 평가를 위해서 안전성 평가 대상에 관한 기술이 이해당사자들이 이해하기 명확하고 쉽게 설정되어야 한다. 방사선적 안전성 평가 시나리오란 처분장으로부터 유출된 방사성 물질들이 공학적 방벽과 천연 방벽을 거쳐 생태계로 어떻게 이동하는가에 대한 설명으로 안전성 평가를 위한 일종의 대본과 같은 역할을 한다. 본 논문에서는 핵종 이동 현상을 RES(Rock Engineering System) 방법론에 의거 기술하였다. 국내 처분장의 특성을 고려하여 처분 시설은 연안에 동굴 처분 방식으로 건설된다고 가정하여 생태계를 산정하고, 공학적 및 천연 방벽들이 처분장 설계 시 예상한 기능들을 수행한다고 가정하여, 기준 시나리오를 설정하였다. 또한 다양한 설계 고려 요소들을 고려하여 대안 시나리오들을 도출하고자 하였다. 도출된 시나리오의 주요 항목들을 평가하기 위해서 AMF(Assessment Method Flowchart)를 도출하였다. 주어진 지형 조건에 따라 확률론적 방사선적 안전성 평가를 위해 각 지층 구조별 이동 거리 및 시간을 CONNECTFLOW를 이용해 산정하고, 그 결과들을 Response surface method를 이용해 확률 밀도함수로 도출하여 방사선적 안전성 종합 평가 코드인 MASCOT-K의 입력 자료로 활용되도록 하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.3
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• pp.217-233
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• 2014

Securing the radiological safety is a prerequisite for the safe management of the naturally occurring radioactive materials (NORM) which cannot be reused. This becomes a crucial focus of our R&D efforts upon the implementation of the Act on Protective Action Guidelines against Radiation in the Natural Environment. To secure the safety, the establishment of technical bases and procedures for securing radiological safety related to the disposal of NORM is required. Thus, it is necessary to analyze the characteristics, to collect the data, to have the radiological safety assessment methodologies and tools, to investigate disposal methods and facilities, and to study the effects of the input data on the safety for the NORM wastes. Here, we assess the environmental impact of the NORM waste disposal with respect to the major domestic and foreign NORM characteristics. The data associated with major industries are collected/analyzed and the status of disposal facilities and methodologies relevant to the NORM wastes is investigated. We also suggest the conceptual design concept of a landfill disposal facility and the management plan with respect to the major NORM wastes characteristics. The radionuclide pathways are identified for the atmospheric transport and leachate release and the environmental impact assessment methodology for the NORM waste disposal is established using a relevant code. The assessment and analysis on the exposure doses and excessive cancer risks for the NORM waste disposal are performed using the characteristics of the representative domestic NORM wastes including flying ash, phosphor gypsum, and redmud. The results show that the exposure dose and the excessive cancer risks are very low to consider any radiation effects. This study will contribute to development in the areas of the regulatory technology for securing radiological safety relevant to NORM waste disposal and to the implementation technology for the Act.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2015.10a
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• pp.421-422
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• 2015

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.121-122
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• 2009

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.88-89
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• 2009

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.5-11
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• 2010

In this paper, we are suggested development of dual-mode detector for dual-energy digital radiography. Design of dual-energy radiography module for commercial BIS (Baggage Inspection System) is used in the spectrum of the X-ray generator and detector for dual-mode features and radiological characteristics were analyzed. BIS suggestl on the image detector module being used to target X-ray tube to simulate X-ray spectrum and simulated spectrum to offer through the new radiographic characteristics of the detector modules were investigated. Using X-ray experiments with an increase in the thickness of the copper filter low energy detector (LED) and high-energy detector (HED) as the difference between the output signal increases. HED, especially in the size of the output signal decreases with increasing thickness of the copper filter was found.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.806-811
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• 1995

DUPIC 핵연료주기에서 기준 핵연료로 설정된 사용후 경수로핵연료, 신 DUPIC 및 사용후 DUPIC핵연료의 핵종별 농도, 방사능, 붕괴열, 위해지수 및 방사선원항을 시간의 함수로 그 변화 특성을 분석하고, 각 인자별로 :-B게 영향을 미치는 주요 핵종의 거동을 물질농도 측면에서 추적하여 분석.평가 하였다. 방사성물질의 농도와 방사능 및 붕괴열 측면에서 모두 사용후 DUPIC핵 연료는 사용후 경수로핵연료에 111해 양적인 감소현상이 뚜렷하게 나타났다. 이는 DUPIC핵 연료주기의 경제적인 이득은 물론 환경 안전성 측면에서 크게 기여할 것임을 시사하고 있다. 한편 섭취 위해지수는 냉각기간에 따라 약간의 차이를 보이나 두 경우 비슷한 것으로 나타났으며, 방사선원 항의 세기에 있어서는 에너지 스펙트럼에 의존하는 것으로 나타났다. 이러한 결과는 향후 전체, DUPIC핵연료주기 평가에 있어서 기본 자료로 유용하게 활용될 수 있을 것으로 기대된다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.331-341
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• 2016

To evaluate the physicochemical and radiological properties of raw materials and by-products in domestic distribution, about 220 samples with 16 species were prepared. We measured the energy spectrum and the chemical content, such as U, Th, and K, using a $LaBr_3$ scintillation detector and ED-XRF. In addition, HPGe detector was used to analyze the radioac-tivity of $^{234}Th$, $^{234}mPa$, and $^{214}Bi$ in uranium decay series and $^{228}Ac$, $^{212}Pb$, and $^{208}Tl$ in thorium decay series, and $^{40}K$. The correlation between characteristic variables, such as the count rate in several ROIs, chemical content, and radioactivity, was assessed to infer the radioactivity of natural radionuclides through a rapid screening method. Based on the results, a characteristic database for raw material and by-product in domestic distribution was established and it will provide useful information in the analysis procedure and improve the accuracy and reproducibility in the analysis of natural radionuclides.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.189-192
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• 2004

본 연구에서는 한국형 중저준위 방사성폐기물 처분시설 안전성 평가를 위한 FEP 목록 도출 방법 및 선별 원칙들을 제시하였으며, 처분장에서의 핵종 이동 시나리오에 대해서는 생태계의 특성 및 공학방벽에 따라 각각의 RES (Rock Engineering System)를 구성하여 각 상황별 핵종이동을 모사 할 수 있도록 제안하였다. 또한 각 시나리오별 안전성 평가를 위하여 적용 가능한 해석 코드를 제안하였으며, 종합 성능 평가를 위한 보완점을 지적하였다. 추후 종합 성능 평가 시스템을 통해 최종적으로 도출될 안전성 평가 결과는 한국형 처분장 설계시에 활용될 수 있을 것으로 기대된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3517-3523
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• 2010

Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm ${\times}$ 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.