• Journal of Contemporary Eastern Asia
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• 제18권1호
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• pp.153-174
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• 2019

South Korea's energy policy has been historically established through an energy production structure that relies on thermal and nuclear power generation in relation to a centralized 'Hard Energy System'. However, climate change issues are forcing the transition to renewable energy, and it is crucial for local governments to enable this. This study analyses Seoul city's local energy governance, which is known as One Less Nuclear Power Plant Initiative, by applying the collaborative governance framework inspired by Ansell and Gash (2008) and the Reflexivity framework of Confucianism. It is considered that the local energy governance model of Seoul city can be used as a model by other local governments, and it will eventually lead to a decentralized energy system in this era of energy transition.

• 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.

• ALGAE
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• 제19권3호
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• pp.257-270
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• 2004

In order to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea, the species composition and biomass of marine algae at the discharge canal of Uljin nuclear power plant on the East Coast of Korea were investigated seasonally from February 1992 to October 2000. 107 species of marine algae were found at the discharge canal during the past nine years. In general, the number of species observed was abundant in spring or summer and less in autumn or winter. 27 species (4 blue-green, 5 green, 6 brown and 12 red algae) of marine algae occurred more than 1/ 6 frequency and thus can be categorized as warm tolerant species. Among these, one brown (Dictyota dichotoma) and four red algae (Gelidium amansii, Anphiroa ephedraea, Hydrolithon sargassi, Marginisporum crassissimum) are recorded as warm tolerant marine algae for the first time in Korea. Padina arborescens, Anphiroa zonata and Corallina pilulifera were common species found more than 75% frequency. Seasonal fluctuations of mean biomass were 0-1,330 g dry wt m^(-2) and dominant species in biomass were Corallina pilulifera (contribution to a total biomass proportion 34%), Anphiroa zonata (23%), Padina arborescens (18%) and Sargassum micracanthum (11%). The red algae appeared as predominant algal group at the discharge canal of Uljin nuclear power plant in the qualitative and quantitative aspects. The green algae such as Enterornorpha compressa appeared rather frequently at the discharge canal, but the biomass proportion was very low, in contrast to Kori nuclear power plant where there was definite green algal dominance. Differences in algal communities developed at the discharge canals of Uljin and Kori nuclear power plant on the East Coast of Korea, particularly biomass proportions of green algae, can probably be related to local environmental factors such as water velocity through the canal and natural seawater temperatures.

• 한국압력기기공학회 논문집
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• 제5권1호
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• pp.32-37
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• 2009

The emergency diesel generator (EDG) in a nuclear power plant (NPP) shall start within 10 secondss and supply electrical power to engineered safety features within one minute and less if a loss of offsite power (LOOP), A design-basis event, or their combination occur. Each NPP has an EDG set consisting of two diesel generators for redundancy. In addition to the EDG set, an alternate Alternating Current Diesel Generator (AAC DG) is installed and shared by several units to cope with a station black out (SBO), i.e., loss of the offsite power concurrent with reactor trip and unavailability of the EDG set. The objective of this study is to analyze the failure data of emergency diesel generators reported in overseas nuclear power plants.

• Journal of Radiation Protection and Research
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• 제47권2호
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• pp.99-106
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• 2022

Background: The radionuclide inventory calculation codes such as ORIGEN and FISPACT collapse neutron reaction libraries with energy spectra and generate an effective one-group cross-section. Since the nuclear cross-section data, energy group (g) structure, and other input details used by the two codes are different, there may be differences in each code's activation inventory calculation results. In this study, the calculation results of neutron-induced activation inventory using ORIGEN and FISPACT were compared and analyzed regarding radioactive waste classification and worker exposure during nuclear decommissioning. Materials and Methods: Two neutron spectra were used to obtain the comparison results: Watt fission spectrum and thermalized energy spectrum. The effective one-group cross-sections were generated for each type of energy group structure provided in ORIGEN and FISPACT. Then, the effective one-group cross-sections were analyzed by focusing on ⁵⁹Ni, ⁶³Ni, ⁹⁴Nb, ⁶⁰Co, ¹⁵²Eu, and ¹⁵⁴Eu, which are the main radionuclides of stainless steel, carbon steel, zircalloy, and concrete for decommissioning nuclear power plant (NPP). Results and Discussion: As a result of the analysis, ¹⁵⁴Eu and ⁵⁹Ni may be overestimated or underestimated depending on the code selection by up to 30%, because the cross-section library used for each code is different. When ORIGEN-44g, -49g, and -238g structures are selected, the differences of the calculation results of effective one-group cross-section according to group structure selection were less than 1% for the six nuclides applied in this study, and when FISPACT-69g, -172g, and -315g were applied, the difference was less than 1%, too. Conclusion: ORIGEN and FISPACT codes can be applied to activation calculations with their own built-in energy group structures for decommissioning NPP. Since the differences in calculation results may occur depending on the selection of codes and energy group structures, it is appropriate to properly select the energy group structure according to the accuracy required in the calculation and the characteristics of the problem.

• Nuclear Engineering and Technology
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• 제21권1호
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• pp.18-31
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• 1989

대기오염의 제어가 발전 단가에 미치는 영향을 분석하기 위하여 전산 모델이 개발 되었다. POGEN은 석탄 화력 발전소에 대해 대기오염 제어 비용을 가산한 균등화 발전 단가를 계산한다. 부 프로그램 Pollution은 대기 오염 제어 비용을 가산한 지배 방정식을 사용하여 총 자본 비용과 변동비용을 계산한다. 이 비용은 균등화 발전 단가를 계산하는 부 프로그램 GENeration의 추가 입력으로 사용된다. 탈황설비의 직접 비용에 대한 Pollution을 이용한 결과는 경험이 풍부한 선진국에서 발간된 비용 자료로써 검증하였다. 2001년의 전력 생산비용은 석탄화력발전소에 적용된 세 가지의 규제 시나리오에 의해 추정되었다. 입력 변수의 중요도와 미래 발전소에 대한 입력 변수에 포함된 불확실성 때문에 생기는 불확실도의 전파를 검토하기 위해 Latin Hypercube Sampling과 Multiple Least Squares 방법을 사용하여 민감도 분석과 불확실도 분석을 수행하였다. 가장 민감한 입력 변수는 원자력, 화력 공히 할인률이다. 배출가스제어 비용으로서 9-11 mills/kWh 정도가 추가되어야 한다. 이 비용은 전력 생산비용의 거의 20 퍼센트가 되고, 이에 해당하는 투자비는 1GW 용량의 석탄 화력발전소 초기 투자비용의 40%가 될 것이다. 원자력 발전에 대한 단가는 90퍼센트의 신뢰도로써 32.6-65.9, 석탄 화력에 대해서는 45.5-60.5 mills/kWh가 되며, 엄격한 규제 분위기 하에서는 원자력이 95%의 신뢰도로써 유리할 것이 전망된다.

• Nuclear Engineering and Technology
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• 제37권3호
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• pp.273-278
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• 2005

Key concepts in South Korean nuclear safety regulation are safety and risk. Nuclear regulation in South Korea has required reactor designs and safeguards that reduce the risk of a major accident to less than one in a million reactor-years-a risk supposedly low enough to be acceptable. To date, in South Korean nuclear safety regulation has involved the establishment of many technical standards to enable administration enforcement. In scientific lawsuits in which the legal issue is the validity of specialized technical standards that are used for judge whether a particular nuclear power plant is to be licensed, the concept of uncertainty law is often raised with regard to what extent the examination and judgment by the judicial power affects a discretion made by the administrative office. In other words, the safety standards for nuclear power plants has been adapted as a form of the scientific technical standards widely under the idea of uncertainty law. Thus, the improvement of nuclear safety regulation in South Korea seems to depend on the rational lawmaking and a reasonable, judicial examination of the scientific standards on nuclear safety.

• 한국지반공학회논문집
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• 제34권9호
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• pp.43-49
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• 2018

감쇠식을 이용한 지진재해평가는 다양한 사회기반시설을 대상으로 한 프로젝트에 널리 수행된다. 이에 따라, 다양한 지반 조건에서의 최대지반가속도 예측을 위한 수많은 감쇠식과 관련 연구들이 수십 년에 걸쳐 이루어졌다. 하지만 기존에 제시된 대부분의 감쇠식들은 일반적으로 토층 상부 30m에 대한 평균 전단파 속도를 지반 분류의 기준으로 적용하여 다양한 지반 조건에서의 지진 규모나 최대지반가속도를 예측할 수 있도록 제시되어 터널이나 원자력 발전소와 같이 기반암을 기초로 하여 건설되는 특수한 유형의 사회기반시설물에 적용하기에는 불확실성을 지니고 있었다. 본 연구에서는 일본에서 측정된 데이터를 기반으로 암반 조건에서의 최대지반가속도 예측이 가능한 개선된 상관관계를 제시하였으며, 산출된 결과를 기존에 제시된 감쇠식을 통해 계산된 결과와 비교하였다. 분석결과, 기존에 제시된 감쇠식들을 통해 최대지반가속도를 예측할 경우, 200km 미만의 거리 내에 위치한 암반지역에서의 최대지반가속도를 상대적으로 과소 예측 하는 것으로 나타났다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1990년도 추계학술대회논문집; 한양대학교, 서울; 24 Nov. 1990
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• pp.113-124
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• 1990

Tap lines are small branch piping generally less than two inches in diameter. They typically branch off of header piping having a much larger diameter. An example of a common tap line is a 3/4 inch size high point vent or low point drain. Most tap lines have at least one valve near the header tap connection to provide isolation. Two valves are often required for double isolation. A light water reactor(LWR) nuclear power plant will have several hundred tap lines. These lines come in many sizes and shapes and serve numerous functions. A single process piping valve may have three different tap lines associated with it (figure 1). Table 1 delineates the different categories of tap lines. Vibration failures of tap lines are a common occurrence in all industrial plants including nuclear and fossil power plants. These types of failures constitute a significant percentage of all piping related failures. An unscheduled plant shutdown or outage resulting from the failure of a tap line decreases plant reliability and may have a detrimental effect on plant safety. Most tap line vibration failures can be avoided through the use of appropriate routing and support techniques. Standardized designs can be developed for use in a myriad of applications. These designs will not only minimize failures but will also reduce the necessary analysis and installation efforts.

• Journal of the korean society of oceanography
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• 제33권1-2호
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• pp.35-40
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• 1998

In February and April 1997, three temporary interruptions of electric power production at the Uljin Nuclear Power Plant in the east coast of Korea were caused by the malfunction of the cool-ing-water supply unit. The clogging of the drum screens inside the unit caused by the surface swarm of the euphausiid Euphausia pacifica Hansen might be responsible for the malfunction. These incidents were of particular interest since such interruption of reactors' operation by krill swarms had not previously been reported. Using samples caught by the drum screens inside the cooling water-supply unit, we investigated the population structure of surface swarms. One occasion of nighttime and three occasions of daytime surface swarms were found in February and April 1997, respectively. The foreguts of more than 60% of E. pacifica in nighttime surface swarm were in full condition. This evidence suggests that E. pacifica aggregates to the surface water at night for feeding. In daytime surface swarms consisting of mature E. pacifica, however, foreguts in full condition were only found in less than 10eio of krill examined, suggesting that daytime surface swarms are closely related to breeding activity. During the study period, the growth rate of mature females was more than twice higher than that of mature males. Analyses of the sex-ratio and length-frequency data show a decrease in the portion of males with increasing size. There was a decline in the number of males of 19 mm in length. Energy loss during spermatophore transfer may result in the death of male E. pacifica, as found in male E. superba.