• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1217-1233
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• 2018

Following a surge of interest in multi-unit risk in the last few years, many recent studies have suggested methods for multi-unit probabilistic safety assessment (MUPSA) and addressed several related aspects. Most of the existing studies though focused on two-unit nuclear power plant (NPP) sites or used rather simplified probabilistic safety assessment (PSA) models to demonstrate the proposed approaches. When considering an NPP site with three or more units, some approaches are inapplicable or yield very conservative results. Since the number of such sites is increasing, there is a strong need to develop and validate practical approaches to the related MUPSA. This article provides several detailed approaches that are applicable to multi-unit Level 1 PSA for sites with up to six or more reactor units. To validate the approaches, a multi-unit Level 1 PSA model is developed and the site core damage frequency is estimated for each of four representative multi-unit initiators, as well as for the case of a simultaneous occurrence of independent single-unit initiators in multiple units. For this purpose, an NPP site with six identical OPR-1000 units is considered, with full-scale Level 1 PSA models for a specific OPR-1000 plant used as the base single-unit models.

• Nuclear Engineering and Technology
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• 제37권2호
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• pp.191-200
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• 2005

Shaking table tests of the seismic behavior of a steel frame structure model were performed. The purpose of these tests was to estimate the effects of a near-fault ground motion and a scenario earthquake based on a probabilistic seismic hazard analysis for nuclear power plant structures. Three representative kinds of earthquake ground motions were used for the input motions: the design earthquake ground motion for the Korean nuclear power plants, the scenario earthquakes for Korean nuclear power plant sites, and the near-fault earthquake record from the Chi-Chi earthquake. The probability-based scenario earthquakes were developed for the Korean nuclear power plant sites using the PSHA data. A 4-story steel frame structure was fabricated to perform the tests. Test results showed that the high frequency ground motions of the scenario earthquake did not damage the structure at the nuclear power plant site; however, the ground motions had a serious effect on the equipment installed on the high floors of the building. This shows that the design earthquake is not conservative enough to demonstrate the actual danger to safety related nuclear power plant equipment.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.46-50
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• 1996

Tritium dose management is an important aspect of the radiation protection program at CANDU type reactor sites. This paper describes the bioassay and dosimetry of tritium at CANDU reactor sites, especially for Wolsung Nuclear Power Plant. It presents a compilation of information drawn from published papers, technical reports, international and national guidelines as well as practical experience both in Korean and Canadian CANDU Nuclear Power Plants. The implementation of this program would provide a technical basis for demonstrating to workers, managers and regulators that tritium bioassay measurements, dose calculations and records should be of acceptable quality and should meet overall radiation protection program objectives.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권3호
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• pp.1-9
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• 2017

The numerical analysis of groundwater flow is indispensable for predicting problems associated with water resource development, civil works, environmental hazards, and nuclear power plant construction. Korea lacks public regulatory procedures and guidelines for groundwater flow modeling, especially in nuclear facility sites, which makes adequate evaluation difficult. Feasible step-by-step guidelines are also unavailable. Consequently, reports on groundwater flow modeling have low-grade quality and often present controversial opinions. Additionally, without public guidelines, maintaining consistency in reviewing reports and enforcing laws is more challenging. In this study, the guidelines for groundwater flow modeling were reviewed for three countries - the United States (Documenting Groundwater Modeling at Sites Contaminated with Radioactive Substances), Canada (Guidelines for Groundwater Modelling to Assess Impacts of Proposed Natural Resource Development Activities), and Australia (Australian Groundwater Modelling Guidelines), with the aim of developing groundwater flow modeling regulatory guidelines that can be applied to nuclear facilities in Korea, in accordance with the Groundwater Act, Environmental Impact Assessment Act, and the Nuclear Safety Act.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.751-752
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• 2004

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.432-432
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• 2002

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.488.2-488.2
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• 2003

• 자원환경지질
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• 제51권2호
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• pp.203-211
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• 2018

국내 원전부지 지진재해도 평가 경험을 바탕으로 향후 지진재해도 평가 시 보다 정량적인 평가를 위하여 고려하여야 할 사항에 대하여 점검하였다. 지진재해도 평가 방법을 양분하는 것으로 알려진 결정론적 방법과 확률론적 방법에 대하여 간단히 소개하였으며, 대부분의 후속 논의는 확률론적 지진재해도 평가에 집중하였다. 이 평가를 국내 원전부지에 적용한 과거 사례를 토대로 제기된 불확실성의 원인을 추적하였다. 확률론적 지진재해도 평가의 고려사항으로 전문가의 역할, 대표지진목록 작성, 지진원 설정, 지진-지반운동 관계식 개발 및 지진재해도 평가 절차에 대하여 토의하였다. 각 주제별로 불확실성을 증가시키는 요인을 분석하고 국내 환경에 적합한 해결 방안을 토의하였다.

• 방사성폐기물학회지
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• 제14권2호
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• pp.189-200
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• 2016

타지키스탄공화국에는 10군데의 우라늄광산 부지에 55백만톤의 우라늄광산 폐기물이 적치 되어 있는데 부지 면적이 200 핵 타아르에 달한다. 이에 따라 우라늄 폐광과 폐기물의 안전한 관리가 주요 이슈로 부각되고 있다. 부지 복원을 위한 천연방벽과 인공방벽으로 구성된 다중 복토층은 성능 목표와 부지 조건을 고려하여 설치되어야 한다. 본 논문의 목적은 Degmay 부지에 장기간 (100년 이상)의 환경보호를 제공할 수 있는 경제적인 다중 복토층 개념을 제시 하는 것이다. HELP 코드를 사용하여 Degmay 부지의 복토층 설계 개념의 평가를 수행하였다. 그 결과 70 cm의 덮개층, 30 cm의 배수층, 지오멤브레인 라이너 그리고 60 cm의 토양 방벽층으로 구성된 복토층 개념이 두께를 최소화 할 수 있고 비교된 여러 설계개념 중 가장 경제적인 설계 안으로 제시되었다.

• 한국자기공명학회논문지
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• 제19권1호
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• pp.29-35
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• 2015

The microscopic dynamics of $CsH_2PO_4$, with two distinct hydrogen bond lengths, are studied by static nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR. The proton dynamics of the two crystallographically inequivalent hydrogen sites were discussed in terms of the $^1H$ NMR and $^1H$ MAS NMR spectra. Although the hydrogen bonds have two inequivalent sites, H(1) and H(2), distinct proton dynamics for the two sites were not found. Further, the $^{133}Cs$ spectrum is more or less continuous near $T_{C1}$ (=153 K). Finally, the phase transition mechanism of $T_{C1}$ in $CsH_2PO_4$ is related to the ordering of protons.