• 제목/요약/키워드: Alternative energy

검색결과 2,160건 처리시간 0.039초

Simulation of reactivity-initiated accident transients on UO2-M5® fuel rods with ALCYONE V1.4 fuel performance code

  • Guenot-Delahaie, Isabelle;Sercombe, Jerome;Helfer, Thomas;Goldbronn, Patrick;Federici, Eric;Jolu, Thomas Le;Parrot, Aurore;Delafoy, Christine;Bernaudat, Christian
    • Nuclear Engineering and Technology
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    • 제50권2호
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    • pp.268-279
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    • 2018
  • The ALCYONE multidimensional fuel performance code codeveloped by the CEA, EDF, and AREVA NP within the PLEIADES software environment models the behavior of fuel rods during irradiation in commercial pressurized water reactors (PWRs), power ramps in experimental reactors, or accidental conditions such as loss of coolant accidents or reactivity-initiated accidents (RIAs). As regards the latter case of transient in particular, ALCYONE is intended to predictively simulate the response of a fuel rod by taking account of mechanisms in a way that models the physics as closely as possible, encompassing all possible stages of the transient as well as various fuel/cladding material types and irradiation conditions of interest. On the way to complying with these objectives, ALCYONE development and validation shall include tests on $PWR-UO_2$ fuel rods with advanced claddings such as M5(R) under "low pressure-low temperature" or "high pressure-high temperature" water coolant conditions. This article first presents ALCYONE V1.4 RIA-related features and modeling. It especially focuses on recent developments dedicated on the one hand to nonsteady water heat and mass transport and on the other hand to the modeling of grain boundary cracking-induced fission gas release and swelling. This article then compares some simulations of RIA transients performed on $UO_2$-M5(R) fuel rods in flowing sodium or stagnant water coolant conditions to the relevant experimental results gained from tests performed in either the French CABRI or the Japanese NSRR nuclear transient reactor facilities. It shows in particular to what extent ALCYONE-starting from base irradiation conditions it itself computes-is currently able to handle both the first stage of the transient, namely the pellet-cladding mechanical interaction phase, and the second stage of the transient, should a boiling crisis occur. Areas of improvement are finally discussed with a view to simulating and analyzing further tests to be performed under prototypical PWR conditions within the CABRI International Program. M5(R) is a trademark or a registered trademark of AREVA NP in the USA or other countries.

원자력발전을 넘어: 위험, 대안, 그리고 비전문가 역할 (Beyond Nuclear Power: Risks, Alternatives, and Laypersons' Role)

  • 허찬란;권상철
    • 한국경제지리학회지
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    • 제24권2호
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    • pp.163-180
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    • 2021
  • 원자력발전은 위험을 안고 있음에도 많은 국가에서 에너지 공급원으로 그리고 지구온난화 대응으로 중요하게 자리잡고 있다. 핵에너지는 방사능 오염의 위험과 핵무기의 위협 그리고 핵폐기물 처리의 문제를 가지고 있으나 효율적인 신기술로 안전 관리가 가능하다는 기술낙관주의가 전문가 그리고 정부 주도로 주류를 이루어 왔다. 그러나 체르노빌 그리고 후쿠시마 원전 사고는 전세계적으로 핵발전의 대안을 모색하는 관심과 노력은 확대되어 대안 모색으로 지속가능한 재생 에너지의 생산을 확대하는 노력, 에너지의 효율적 전달을 위한 스마트그리드와 환경친화적 소비 행태를 통한 에너지 사용 절감, 그리고 핵폐기물의 처리 등을 포함한 환경의 수용능력을 감안한 청지기 정신을 강조한다. 보다 근본적인 대안 운동으로는 대규모 원전 사고를 경험하며 기존 전문가와 정부가 중심이 되어 형성해온 기술주의가 배제했던 지역에서의 피해 사례와 이를 고려하지 못하는 접근에 대한 불만이 보다 광범위하게 피해자, 기술자, 일반인 등이 대안운동을 전개한다. 이들 비전문가들은 지역의 오염을 감지하고 대중의 일상생활에 심각하게 영향을 위험과 감정을 고려하는 능력을 가진 반전문가로 등장한다. 이들은 광범위한 지역에서 원자력에 대한 대안적 지식을 구성하고 합법화하는데 중요한 역할을 한다.

THREE-DIMENSIONAL CRYSTALLIZING ${\pi}-BONDINGS,\;{\pi}-FAR$ INFRARED RAYS AND N-MACHINE

  • Oh, Hung-Kuk
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1996년도 추계학술발표회 논문집
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    • pp.34-44
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    • 1996
  • N-machine produces more than input energy at above 3000 rpm. any space energy is absorbed when the N-machine is rotating at a very high velocity. Laws of electromagnetics verify that normal conduction is due to that electrons moves from one three-dimensional crystallizing ${\pi}-bonding$ orbital to next. The ${\pi}-far$ infrared rays are generated from the resonance and rotation of the electrons on the orbitals of three-dimensional crystallizing ${\pi}-bonding$ atoms. Material in universe is composed of ${\pi}-rays$, which have alternative outward electric field. If the alternative outward electric fields of the ${\pi}-rays$ are resonant each other they make attraction force, which is the gravity. The collection of space energy is due to a attraction force between the radially alternating electric field and the ${\pi}-far$ infrared rays in the space. Electrons flow by absorbed density difference of ${\pi}-far$ infrared rays along a conduction wire, which also verifies that normal electron conduction is due to a flow from one three-dimensional crystallizing ${\pi}-bonding$ orbital to next.

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차세대에너지시스템 구축을 위한 친환경 도시계획 시나리오 검토 (An Analysis of Examination of Eco-City Planning Scenario for Constructing Urban Integrated Energy System)

  • 여인애;이정재;윤성환
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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    • pp.181-184
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    • 2009
  • This study aimed at framing alternative urban planning scenarios reflecting urban planning factors, performing urban climate simulation and evaluating eco-friend and low energy characteristics of each scenario on the viewpoint of urban temperature and energy savings on the target of the costal city including Haeundae District in Busan The results are as follows. 1)The fact that urban higher temperature is approximately 2.5 times higher in the building constructed area than whole urban area was represented severe higher temperature phenomenon in the built-up area. Ground greening, water scenario and soil scenario could be expected peek air temperature alleviating effect in order. Especially water scenario had significant effect(maximum $2.5^{\circ}C$) on lowering of air temperature.

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탈 의료화로서의 대체의학에 관한 논점 (An Arguing Point on the Alternative Medicine as a Withdrawal Medicine)

  • 최찬호
    • 대한예방한의학회지
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    • 제11권1호
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    • pp.85-99
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    • 2007
  • This study aimes to understand trends in alternative medicine use as new therapeutic ways to overcome the limits of western medicine, and is primarily concerned with function of alternative medicine to influence cancer theraphy in the United States after 1970s. Features of oriental medicine and western medicine through the comparison of Quantum medicine and Newton physics are pointed as the basic theory in alternative medicine. Homeopathic medicine, Chiro practice, Aroma theraphy, Transcendental meditation, Acupuncture is shortly is shortly introduced by alternative medicine use. The advantage of this study is to gain as follows : Firstly, To be recognized alternative function of cancer theraphy by Western nations including United States. Secondly, To understand the integrative program utilized as the alternative ways of cancer theraphy in the field. Thirdly, To understand side effects in alternative medicine use. :astly, To recommand marketing stratigies on alternative medicine services to develop Korean health tourism. In conclusion, it is increasingly emphasized that the importance of alternative medicine in relation to health promotion in the western nations. Western travelers expect that alternative medicine service is attractive and effective as the complementary function on incurable disease. Health tourism to experience alternative medicine services by travel will be expected one of the key industries in the future.

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수소가스 부취제가 연료전지의 성능에 미치는 영향 연구 (A Study on Influence of Fuel Cell Performance by Hydrogen Odorant)

  • 한상원;오석환;김영규;이승훈;채재우
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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    • pp.491-494
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    • 2008
  • The hydrogen fuel and fuel cell which have high energy efficiency and low pollutant emission are getting interest as an alternative energies due to the fossil fuel exhaust, green house effect and atmospheric pollutant problems. The hydrogen gas is very effective as an alternative energy. But, if it is leaked into the air it forms the mixed gas with the air then the danger of the explosion is risen up. So, the secure the safety is mostly important. In this research, to detect the leakage of the hydrogen rapidly, added the odorant materials which don't include the sulfur component into the hydrogen gas and researched on the effect of each odorant on the performance of the fuel cell. As the results, setting the cumulation electric power on the basis and comparing the pure hydrogen, 2,3-Butanedione 5ppm mixed gas 86.1%, 5-Ethylidene-2-Norbornene 17ppm mixed gas 88.2%, Isovaleraldehyde 10ppm mixed gas 74.8%, Ethyl Isobutyrate 2.2ppm mixed gas 93.5% of performance was shown.

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Nuclear power utilization as a future alternative energy on icebreakers

  • M. Bayraktar;M. Pamik
    • Nuclear Engineering and Technology
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    • 제55권2호
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    • pp.580-586
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    • 2023
  • Diversified fuel types such as methanol, hydrogen, liquefied natural gas, ammonia, biofuels, have been come to fore in consideration of the limitations, regulations, environmental perception and efficient use of resources on maritime sector. NE is described as a substantial alternative energy source on the marine vessels in the sense of de-carbonization and fuel efficiency activities carried out by IMO. Although NPVs have been constructed for the merchant, navy and supply fields over the years, their numbers are few and working ranges are quite limited. NE generation techniques, reactor types, safety and security issues in case of any leakage or radiation pollution are analyzed and comparisons are performed between fossil-based fueled and NP based on icebreakers. The comparison are conducted on the basis of dimensions, resistances and operational competences by the VIKOR. NP icebreakers operated in recent years occupy a notable position in the ranking, although fossil fueled ones are most prevalent. Consequently, refueling period and emissions are the principal benefits of NPVs. Nevertheless, the use of such systems on marine vessels especially for merchant ships may come to the fore when all concerns in terms of safety, security and society are resolved since the slightest mistake can have irreversible consequences.

열펌프를 이용한 R22대체 혼합냉매의 성능에 관한 연구 (A Study on the Performance of HCFC22 and Alternative Refrigerants in Heat Pumps)

  • 송영재;정동수
    • 태양에너지
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    • 제18권1호
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    • pp.69-79
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    • 1998
  • This paper is concerned about the performance of HCFC22 alternative refrigerants used in heat pumps and industrial chillers. A water-to-water breadboard heat pump with counter-current heat exchangers and a hermetic compressor was built to carry out the experiments with various refrigerants. For each test, more than 40 temperatures, 4 pressures, power input, mass flow rates of the heat transfer fluids were measured. Refrigerants tested were HCFC22, R290(Propane), an azeotrope of 45%Propane/55%R134a mixture, and a nonazeotropic mixture of Calor 50. All tests were conducted under ARI test A condition. It is found that the COP and capacity of propane were 18% and 2.5% higher than those of HCFC22 while the COP and capacity of 45%Propane/55%R134a mixture were 3.5% and 5.3% higher than those of HCFC22 respectively. Also the COP and capacity of Calor 50 were 17% and 7.8% higher than those of HCFC22. Compressor discharge temperatures of alternative refrigerants were roughly $35^{\circ}C$ lower than that of HCFC22 indicating that these refrigerants are good from the view point of compressor reliability. The charging amounts for the alternative refrigerants were reduced by 40-60% as compared to that of HCFC22. Overall, it can be said that hydrocarbon containing alternative refrigerants are excellent in thermodynamic performance but should be used with considerable care due to their flammability.

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저온용 대체냉매의 성능 특성 연구 (Performance Characteristics Study on an Alternative Refrigerant in Low Temperature Applications)

  • 신정섭;김만회
    • 한국수소및신에너지학회논문집
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    • 제27권4호
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    • pp.462-469
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    • 2016
  • This paper presents the results of thermodynamic cycle analysis and performance tests of alternative mixtures in low temperature applications. Two near-azeotropic binary mixtures R-152a/R-1270 (35:65 by wt.%) and R-290/E170 (35:65 by wt.%) are considered in this study. They have zero ODP (Ozone Depletion Potential) and much lower GWP (Global Warming Potential) than R-404A which is an alternative of R-502. Refrigeration cycle characteristics such as cooling capacity, coefficient of performance, suction and discharge pressures and temperatures are compared to those for the baseline refrigerants (R-502 and R-404A) cycles. The performance tests are conducted at the evaporation and condensation temperatures of $5^{\circ}C$ and $45^{\circ}C$, subcooling and superheating temperatures of $5^{\circ}C$, respectively. Performance comparisons between baseline and alternative refrigerants are conducted on the same cooling capacity. The system performance of newly proposed refrigerant mixtures show promising results.