• 제목/요약/키워드: interim analysis

검색결과 123건 처리시간 0.026초

지중 저장 이산화탄소의 누출 위험도 평가를 위한 결함수 분석 (Fault Tree Analysis for Risk Assessment of CO2 Leakage from Geologic Storage)

  • 이상일;이상기;황진환
    • 환경영향평가
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    • 제18권6호
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    • pp.359-366
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    • 2009
  • CCS (Carbon Capture and Storage) is considered as the most promising interim solution to deal with the greenhouse gas such as $CO_2$ responsible for global warming. Even though carefully chosen geologic formations are known to contain stored gas for a long time period, there are potential risks of leakage. Up to now, applicable risk assessment procedures for the leakage of $CO_2$ are not available. This study presents a basis for risk analysis applicable to a complex geologic storage system. It starts with the classification of potential leakage pathways. Receptors and the leakage effect on them are identified and quantified. Then, a fault tree is constructed, which yields the minimum cut set (i.e., the most vulnerable leakage pathway) and quantifies the probability of the leakage risk through the cut set. The methodology will provide a tool for risk assessment in a CCS project. The outcomes of the assessment will not only ensure the safety of the CCS system but also offer a reliable and efficient monitoring plan.

Development of the Numerical Guide for Cost-Benefit Analysis of Occupational Radiation Exposure In the Korean Next Generation Reactor

  • Sohn, Ki-Yoon;Kang, Chang-Sun
    • Nuclear Engineering and Technology
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    • 제29권1호
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    • pp.78-84
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    • 1997
  • The specific purpose of this study is to develop the numerical guide for the cost-benefit analysis of ORE ($/person-Sv reduction) to meet the criterion of ALARA in the design stage of the KNGR. In deriving the guide, the risk factor which is defined by the risk to unit collective radiation exposure dose (deaths/person-Sv) and the monetary value of human life ($/death) are required. The risk factor has been estimated from various clinical data accumulated for a number of years and continuously modified. And the monetary value of human life is usually quantified using the human capital approach. In this study, the risk to radiation exposure perceived by a group of people is investigated through an extensive poll survey conducted among university students in order to modify the existing risk factor for radiation exposure. And in evaluating the monetary value of human life, the QOL factor is introduced in order to incorporate the degree of public welfare or quality of life. As a result of study, a value within the range of 151, 000~172, 000 dollars per person-Sv reduction is recommended as the appropriate interim numerical guide for cost-benefit analysis of ORE to meet the criterion of ALARA in the design stage of the KNGR. A poll survey was also conducted in order to see whether the public acceptance cost of nuclear power should be incorporated in developing the guide, and the result of study shooed that such a cost does not need to be considered.

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IMPACT ANALYSES AND TESTS OF CONCRETE OVERPACKS OF SPENT NUCLEAR FUEL STORAGE CASKS

  • Lee, Sanghoon;Cho, Sang-Soon;Jeon, Je-Eon;Kim, Ki-Young;Seo, Ki-Seog
    • Nuclear Engineering and Technology
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    • 제46권1호
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    • pp.73-80
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    • 2014
  • A concrete cask is an option for spent nuclear fuel interim storage. A concrete cask usually consists of a metallic canister which confines the spent nuclear fuel assemblies and a concrete overpack. When the overpack undergoes a missile impact, which might be caused by a tornado or an aircraft crash, it should sustain an acceptable level of structural integrity so that its radiation shielding capability and the retrievability of the canister are maintained. A missile impact against a concrete overpack produces two damage modes, local damage and global damage. In conventional approaches [1], those two damage modes are decoupled and evaluated separately. The local damage of concrete is usually evaluated by empirical formulas, while the global damage is evaluated by finite element analysis. However, this decoupled approach may lead to a very conservative estimation of both damages. In this research, finite element analysis with material failure models and element erosion is applied to the evaluation of local and global damage of concrete overpacks under high speed missile impacts. Two types of concrete overpacks with different configurations are considered. The numerical simulation results are compared with test results, and it is shown that the finite element analysis predicts both local and global damage qualitatively well, but the quantitative accuracy of the results are highly dependent on the fine-tuning of material and failure parameters.

조현병 환자에서 Paliperidone Extended Release의 효능, 안전성 및 내약성 : 48주 개방형, 전향적 연구의 24주 중간 분석 (Tolerability, Safety and Effectiveness of Paliperidone ER in Patients with Schizophrenia : A 24-Week Interim Analysis of the 48-Week Open-Label, Prospective, Switch Study)

  • 최유라;정동청;김은영;김세현;이현정;이남영;장성만;심주철;주은정;김재진;이상혁;정영철;김용식;안용민
    • 생물정신의학
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    • 제20권1호
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    • pp.12-20
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    • 2013
  • Objectives We investigated the tolerability, safety, and treatment response to flexible-dose paliperidone ER in patients with non-acute schizophrenia in whom previous antipsychotic drugs were ineffective. Methods This 24-week interim analysis of the 48-week multicenter, prospective, open-label study assessed effectiveness using the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Schizophrenia-Severity (CGI-SCH-S) Scale, Personal and Social Performance (PSP) and Drug Attitude Inventory (DAI). Safety and tolerability were assessed using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) and Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS). Results Effectiveness was assessed in 169 patients. Significant improvement in the PANSS total score was observed by week-1 and continued until week-24. The response rate was 33%. The CGI-SCH-S and PSP total scores significantly improved during 24 weeks ; however, no change occurred in the total DAI. Fifty-nine percent of patients reported adverse events, of which extrapyramidal symptoms were the most frequent (19.0%). The DIEPSS and LUNSERS scores were improved after 24 week. Conclusions Switching to the flexible-dose paliperidone ER from an ineffective antipsychotic drug was safe, tolerable, and showed a good treatment response in Korean patients with schizophrenia.

용접구조물의 피로설계를 위한 유한요소 해석 및 통합 피로선도 초안 개발 (Finite Element Analysis and Development of Interim Consolidated 5-N Curve for Fatigue Design of Welded Structure)

  • 김종성;진태은;홍정균
    • 대한기계학회논문집A
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    • 제27권5호
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    • pp.724-733
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    • 2003
  • Fatigue design rules for welds in the ASME Boiler and Pressure Vessels Code are based on the use of Fatigue Strength Reduction Factors(FSRF) against a code specified fatigue design curve generated from smooth base metal specimens without the presence of welds. Similarly, stress intensification factors that are used in the ASME B3l.1 Piping Code are based on component S-N curves with a reference fatigue strength based on straight pipe girth welds. But the determination of either the FSRF or stress intensification factor requires extensive fatigue testing to take into account the stress concentration effects associated with various types of component geometry, weld configuration and loading conditions. As the fatigue behavior of welded joints is being better understood, it has been generally accepted that the difference in fatigue lives from one type of weld to another is dominated by the difference in stress concentration. However, general finite element procedures are currently not available for effective determination of such stress concentration effects. In this paper, a mesh-insensitive structural stress method is used to re-evaluate the S-N test data, and then more effective method is proposed for pressure vessel and piping fatigue design.

농촌마을종합개발사업의 공동소득사업 성과분석 (Performance Analysis on Income Generation Works in Comprehensive Rural Village Development Project by Their Implementation)

  • 양원식;최수명
    • 농촌계획
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    • 제19권1호
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    • pp.55-70
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    • 2013
  • Since 2004, Ministry for Food, Agriculture, Forestry and Fisheries(MIFAFF) has been carrying out comprehensive rural village development project as the core one of Rural Area Development Schemes in Korea. Up to now, 56 projects had been completed after having with 5-year plan implementation period, on which it is possible to try post-project evaluation works. This study aims to propose a rational income-generation works model of comprehensive rural village development project, based on fulfillment checking results of their statutory stepwise working procedures specified in the project guidelines and their interim/post project performance analysis results in 56 project areas above mentioned. In comprehensive rural village development project, income-generation works generally have both quantitative and qualitative effects to rural communities; the former is focussed on income increasement of villagers, while the latter on community revitalization through job creation and spill-over effects of other linked community activities. So, the research works of this study focussed on these two comprehensive effects above mentioned.

Analysis of Characteristics of Spent Fuels on Long-Term Dry Storage Condition

  • Yoon, Suji;Park, Kwangheon;Yun, Hyungju
    • 방사성폐기물학회지
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    • 제19권2호
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    • pp.205-214
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    • 2021
  • Currently, the interim storage pools of spent fuels in South Korea are expected to become saturated from 2024. It is required to prepare an operation plan of a domestic dry storage facility during a long-term period, with the researches on safety evaluation methods. This study modified the FRAPCON code to predict the spent fuel integrity evaluation such as the axial cladding temperature, the hoop stress and hydrogen distribution in dry storage. The cladding temperature in dry storage was calculated using the COBRA-SFS code with the burnup information which was calculated using the FRAPCON code. The hoop stress was calculated using the ideal gas equation with spent fuel information such as rod internal pressure. Numerical analysis method was used to calculate the degree of hydrogen diffusion according to the hydrogen concentration and temperature distribution during a dry storage period. Before 50 years of dry storage, the cladding temperature and hoop stress decreased rapidly. However, after 50 years, they decreased gradually and the cladding temperature was below 400 K. The initial temperature distribution and hydrogen concentration showed a parabolic line, but hydrogen was transferred by the hydrogen concentration and temperature gradient over time.

Neutron dose rate analysis of the new CONSTOR® storage cask for the RBMK-1500 spent nuclear fuel

  • Narkunas, Ernestas;Smaizys, Arturas;Poskas, Povilas;Naumov, Valerij;Ekaterinichev, Dmitrij
    • Nuclear Engineering and Technology
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    • 제53권6호
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    • pp.1869-1877
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    • 2021
  • This paper presents the neutron dose rate analysis of the new CONSTOR® RBMK-1500/M2 storage cask intended for the spent nuclear fuel storage at Ignalina Nuclear Power Plant in Lithuania. These casks are designed to be stored in a new "closed" type interim storage facility, with the capacity to store up to 202 CONSTOR® RBMK-1500/M2 casks. In 2016 y, the "hot trials" of this new facility were conducted and 10 CONSTOR® RBMK-1500/M2 casks loaded with the spent nuclear fuel were transported to the dedicated storage places in this facility. During "hot trials", the dose rate measurements of the CONSTOR® RBMK-1500/M2 casks were performed as the dose rate is one of the critical parameter to control and it must be below design (and safety) criteria. Therefore, having the actual data of the spent nuclear fuel characteristics, the neutron dose rate modeling of the CONSTOR® RBMK-1500/M2 cask loaded with this particular fuel was also performed. Neutron dose rate modeling was performed using MCNP 5 computer code with very detailed geometrical representation of the cask and the fuel. The obtained modeling results were compared with the measurement results and it was revealed, that modeling results are generally in good agreement with the measurements.

RUG-III를 이용한 노인환자군분류의 타당성검증 (Application of RUG-m for Long-Term Care Elderly Patients)

  • 이지전;유승흠;오희철;남정모;박은철;이윤환
    • 한국병원경영학회지
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    • 제6권3호
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    • pp.148-166
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    • 2001
  • The purpose of this study is to classify elderly patient in long-term care facilities using RUG(Resource Utilization Group)-III. It is designed by measuring patient medical characteristics and medical staff time. Elderly patients are classified into 7 categories by clinical(medical and behavioral) hierarchical typology of patients. Through the tertiary split, all 44 groups are formulated. This classification is explained by each patient resource(staff time) utilization level which is called CMI(Case-Mix Index). Major findings are as follows; 1. The objects in this study were classified into 35 groups out of 44 groups. The most frequent category is clinical complex category(CCC; 38.9%). And extensive service category(ESC; 18.8%), reduced physical function category(RPC; 13.1%), special rehabilitation category(SRC; 12.8%), and impaired cognitive category(ICC; 0.00%) are followed. 2. The mean of total CMI was $1.02{\pm}0.36$, ranging from 0.68 to 1.44(1 vs 2.12). The mean of CMI of SRC is only 1.17 which should be the highest. The means of ESC and see are equally 1.20. The means of CMI of CCI, ICC, BPC, and RPC were 0.90, 0.75, 0.83 and 0.96, respectively. 3. The validity of this classification was tested. Trend-test using Regression Analysis was done in the secondary split level. SCC, CCC, ICC, and RPC which covered 68.4% of this research objects showed linear trend of CMI in interim classification. This results were statistically significant. 4. In clinical hierarchy, the trend were showed linearity. But the multiple comparison of categories using Scheffe-test showed that SRC, ESC and see had same level of CMI means and CCC and ICC, too. This results were statistically significant. Classifying elderly patients with RUG-III, the results showed partly linear trend in clinical hierarchy and in interim classification in conclusion. But, in clinical hierarchy, it was failed to show the consistent order of CMI. It can be explained by two reasons. One is that this research subjects were overlapped in each clinical hierarchy group. And the other is that the some of the characteristics for clinical hierarchy is not appropriate for them. For the further study, it needs to have proper sample size and to modify RUG-III to K-RUG to consider our.. medical environment.

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기후변화 시나리오를 활용한 한반도 미래 풍력에너지의 시공간적 변동성 전망 (Spatio-temporal variability of future wind energy over the Korean Peninsular using Climate Change Scenarios)

  • 김유미;임윤진;이현경;최병철
    • 대한지리학회지
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    • 제49권6호
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    • pp.833-848
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    • 2014
  • 풍력발전단지의 신규 개발과 안정적인 운영 계획 수립을 위해 기후변화에 따른 미래 풍력에너지의 변동성 정보를 파악하는 것이 필요하다. 본 연구는 IPCC 5차 보고서에서 새롭게 도입된 대표농도경로(Representative Concentration Pathway)를 적용한 기후변화 시나리오 자료를 활용하여 2006년부터 2040년까지의 가까운 미래에 대한 풍력에너지(풍력에너지밀도와 잠재전력생산량)의 시 공간적 변동성을 분석하고자 한다. 사용된 기후변화 시나리오는 지역기후모델 HadGEM3-RA를 이용해 생산된 RCP2.6과 8.5자료이다. 시나리오 생산의 기반이 된 지역기후모델을 과거기간에 대하여 ECMWF의 ERA-interim 재분석자료와 비교분석한 결과, 지역 기후모델은 풍력에너지를 육지에서는 과소, 바다에서는 과대 모의하였다. 그리고 변동성 역시 육지에서 과소, 바다에서는 과대 모의하였다. 미래 풍력에너지는 RCP 시나리오별로 다소 차이가 나타나지만 육지에서 증가, 바다에서는 감소할 것으로 예측되었으며 고도가 높은 산지 및 해안지역에서 미래 풍력에너지의 변동성이 증가할 것으로 분석되었다. 지역별 풍력에너지밀도 분석결과 제주에서 크게 증가할 것으로 예상되었으며 변동성도 크게 증가하였다. 미래 풍력에너지의 변동은 주변 기상장의 변화와 연관 지어 해석이 가능하였으나 큰 변동성으로 인한 불확실성이 증가할 것으로 판단할 수 있다. 본 연구를 통해서 분석된 결과는 미래 에너지 수급 및 활용계획 수립에 있어 기초자료로 활용될 수 있으리라 판단한다.

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