• 의정연구
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• 제23권1호
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• pp.151-185
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• 2017

서울의 '원전하나 줄이기(2012)' 정책은 성공적인 도시 에너지 정책이자, 에너지 전환(energy transition)의 성공사례로 소개되고 있다. 하지만, 본 정책의 이른바 '목표달성'이 어떻게 가능했는지에 대해서는 구체적으로 설명된 바가 없다. 본 연구는 원전하나 줄이기 정책의 높은 수준의 성과가 가능한 이유로, 정책인식, 정책목표, 정책수단 및 정책평가 등의 체계 구성요인 간의 조화를 유지할 수 있었던 서울시의 거버넌스 역량을 핵심 요인으로 제시하였다. 이러한 거버넌스 관점의 설명은 정책의 장(policy arena)으로서의 도시의 중요성을 부각시키고, 도시정부의 역량에 따라 체계의 전반적인 전환 과정에서 내적 일관성을 유지하며 정책체계로서의 항상성과 지속성을 유지할 수 있음을 보여준다. 경성에너지체계로 정의되는 합리성-효율성-중앙집권적 에너지체계는 원전하나 줄이기 정책의 시행과 더불어 연성에너지체계로 이행되기 시작하였다. 에너지체계 운영의 주체로서, 체계전환을 관리하는 서울시의 역량은 따라서 가장 중요한 설명변수가 된다.

• 한국환경복원기술학회지
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• 제16권3호
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• pp.55-62
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• 2013

Generally, the radioactivity from NPP(Nuclear Power Plants) operation can be released below 3% of DRLs(Derived Release Limits) to environment. It was tried to understand which plant was efficient for absorbing radioactivity in this study. Pinus thunbergii Parl. and Viburnum awabuki K. KOCH were analyzed for radioisotope absorption. The samples were collected at three different locations depending on the distance from NPP at the vicinity 10km away, and 30km away. Gamma radionuclide was not detected from the samples, which means that the direct transition into the plant was not significant. Meanwhile, the very low level of radioactive tritium was detected in the samples. One remark was that every plant has different ability for tritium absorption. These results are expected to be applied to propagation and transplanting in radioactively contaminated area or reducing radioactivity in the soil and water near the plants.

• 에너지공학
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• 제21권4호
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• pp.362-372
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• 2012

원전의 증기발생기 전열관은 압력경계 부위로 결함발생으로 인한 누설 시 방사능물질을 함유한 1차 계통의 냉각수가 2차 계통으로 새어나와 발전소 및 대기를 오염시키게 된다. 근래에 전열관의 균열결함은 대개 응력 부식균열이며 전열관의 확관부위, 슬러지 침적부위 그리고 U-bend 등에서 발생한다. 확관부위 및 U-bend 등에서의 균열발생인자 중 가장 영향을 미치는 인자는 잔류응력이다. 폭발확관법이 적용된 한국표준형원전(OPR-1000)의 운전경험에 따르면, 증기발생기 전열관 확관부위에서 가동 초기부터 응력부식균열이 발생해 왔으며, 특히 원주방향 균열이 대량 발생하고 있다. 따라서 본 연구에서는 확관방법에 따른 잔류응력의 분포 및 상태를 비교하였으며, 특정 방향이 우세한 원인을 살펴보았다.

• 전기학회논문지
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• 제67권2호
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• pp.337-342
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• 2018

Spent fuel is moved from the reactor into the spent fuel pool when nuclear power plant permanently shutdown. The sole function of a permanently defueled facility is to store spent fuel in a quiescent state. The function of electric system and loads are reduced. It is necessary to establish an operating strategy of electric system in the permanent shutdown nuclear plant. This paper reviews required loads and design criteria considering transition to permanent shutdown. An operating strategy of onsite electric system is proposed considering decommissioning strategy and stage of defueled condition.

• Nuclear Engineering and Technology
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• 제52권3호
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• pp.560-567
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• 2020

The complexity of safety critical systems of Nuclear Power Plant continues to increase rapidly due its transition from analog to digital systems. It has thus become progressively more imperative to model these systems prior to their implementation in order to meet the high performance, safety and reliability requirements. Timed Petri Nets (TPNs) have been widely used to model such systems for non-functional analysis. The paper presents a novel methodology for the analysis of the performance metrics using PN modeling. The paper uses the isomorphism property of the TPNs and the Markov chains for the performance analysis of the safety critical systems. The presented methodology has been validated on a Shutdown System of a Nuclear Power Plant.

• 소성∙가공
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• 제14권6호
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• pp.565-569
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• 2005

Reactor Vessel is one of the most important structural parts of nuclear power plant. It is manufactured by various steel forgings such as shell, head and transition ring. Head forgings have been made by open die forging process. After steel melting and ingot making, open die forging has been carried out to get a good quality which means high soundness and homogeniety of the steel forgings by using high capacity hydraulic press. This paper introduced the open die forging process and manufacturing experience of large head forgings which can be used for the reactor vessel of 1,000MW nuclear power plant.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 제10회 단조 심포지엄
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• pp.131-139
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• 2005

Reactor Vessel is one of the most important structural part of nuclear power plant. It is manufactured by various steel forgings such as shell, head and transition ring. Head forgings has been made by open die forging process. After steel melting and ingot making, open die forging has been carried out to get a good quality which means high soundness and homogeniety of the steel forgings by using high capacity hydraulic press. This paper introduced the development trend of the open die forging process and manufacturing experience of large head forgings which canl be used for the reactor vessel of nuclear power plant.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.397-400
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• 2005

Reactor Vessel is one of the most important structural part of nuclear power plant. It is manufactured by various steel forgings such as shell, head and transition ring. Head forgings has been made by open die forging process. After steel melting and ingot making, open die forging has been carried out to get a good quality which means high soundness and homogeniety of the steel forgings by using high capacity hydraulic press. This paper introduced the open die forging process and manufacturing experience of large head forgings which cant be used for the reactor vessel of 1,000MW nuclear power plant.

• Journal of Plant Biotechnology
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• 제30권4호
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• pp.387-397
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• 2003

During the first half of twentieth century, even though the importance of non-calorie essential micronutrients of 13 vitamins and 17 minerals has been known to alleviate nutritional disorder; the primary objective of agriculture and plant breeding programs has been to increase the productivity and seed yields, and macronutrients of proteins, fats, and carbohydrates made up the bulk of foodstuff which were used primarily as an energy source. In the last decade it has been found that non-essential micronutrients encompass a vast group of phytochemicals including antioxidants that are not strictly required in the diet but when present at sufficient levels work as health-promoting chemicals. Nowadays agricultural crops are grown for health rather than for food or fiber, and modifying the nutritional compositions of plant foods has become an urgent health issue. To ensure an adequate intake of essential vitamins and minerals, and to increase the consumption of health-promoting phytochemicals, the researches on plant secondary metabolism have been made. The attempt to improve nutritional quality of crops has been blocked by a lack of basic knowledge of plant metabolism. The advent of genomics era enabled new approaches to make crossing regardless of species, family, or phylum barriers, and the accumulation in our basic knowledge on plant secondary metabolism during the coming decade would be tremendous. As the major staple crops contain insufficient amount of many micronutrients, fortification strategy will be a necessary practice. Elevated intake of specific vitamins, C, E, and $\beta$-carotene, mineral selenium, antioxidants, and phytochemicals significantly reduces the risk of chronic disease such as cancer, cardiovascular disorder, diabetis, and other degenerative disease associated with aging. As the attempt to improve the nutritional quality of crops requires the basic knowledges on plant metabolism, plant biochemistry, human physiology, and food chemistry, strong interdisplinary collaboration among plant biotechnologists, human nutritionists, and food scientists will be needed. Inhibition of cancer, cardiovascular disease, and other degenerative disorder may be the biggest goal facing nutritional plant breeders. But the assumption that simply increasing dietary level of any compound will necessarily improve human health is a dangerous idea because many plant secondary products and dietary contaminants have paradoxical (hermetic) effects. Before biotechnical manipulation is undertaken to elevate or reduce any individual constituent of crops, the contribution of the micronutrient to human health must first be investigated.

• Journal of Welding and Joining
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• 제7권3호
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• pp.28-35
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• 1989

It was reported that the toughness for welded region was influenced by various factors such as the gradient for prior austenite grain size, the variation of microhardness and the characteristic microstructure depending on distance from the fusion boundary. Therefore, in order to evaluate the fracture strength of the weldment in which the microstructures change continuously, it is important to assess the peculiar strength of each microstructure in welded region. It was known that the small punch(SP) test technique which was originally developed to study the irradiation damage effect for the structures of nuclear power plant was also useful to investigate the strength evaluating of nonhomogeneous materials. In this paper, by means of a small punch test technique the possibility of evaluating strength of parent and welded region in SS41 and SM53B steels was investigated. The obtained results are summerized as follows: 1) The small punch test which showed markedly the ductile-brittle transition behavior in this experiment may be applied to evaluation for the fracture strength of welded region. 2) It was shown that the ductile-brittle regime lied in Region III(plastic membrane stretching region) of the flow characteristics observed in SP test. 3) The SP test technique which shows a more precipitous energy change transition behavior than the other test technique is able to estimate the more precise transition temperature. 4) It could be seen that in comparision with the structure of parent the structure of weld HAZ in SS41 steel was improved while it in SM53B steel was deteriorated.