• Title/Summary/Keyword: Nuclear activities

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Study on the characteristics of airborne gross alpha and gross beta activities in the vicinity of nuclear facilities

  • Da-Young Gam;Chae-yeon Lee;Ji-Young Park;Hyuncheol Kim;Jong-Myoung Lim
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4554-4560
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    • 2023
  • Continuous monitoring of radioactive substances over a prolonged duration can yield crucial insights into the levels of radiation exposure through inhalation, both in the vicinity of nuclear facilities and/or general environments. In this study, we evaluated long-term measurements (2012-2022) of gross alpha-beta activities in the air in the vicinity of nuclear facilities and reference site, distribution characteristics of temporal trends and spatial fluctuations, and factors affecting radioactivity levels. The average airborne gross-α (in mBq m-3) for onsite and off-site were 0.124 and 0.117, respectively, and the average airborne gross-β (in mBq m-3) measurements were 1.10 and 1.04, respectively. The activity ratio (AR) of gross-α and gross-β were calculated as a ratio of 0.12. The distribution characteristics of gross-α and gross-β activities in this study area are likely influenced by the meteorological factors and variations in airborne PM concentrations rather than the operation of the nuclear facility.

CONTRIBUTION OF NUCLEAR POWER TO THE NATIONAL ECONOMIC DEVELOPMENT IN KOREA

  • Lee, Man-Ki;Nam, Kee-Yung;Jeong, Ki-Ho;Min, Byung-Joo;Jung, Young-Eek
    • Nuclear Engineering and Technology
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    • v.41 no.4
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    • pp.549-560
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    • 2009
  • Over the last three decades, nuclear technology development has played a vital role in the socio-economic development of the Republic of Korea. This study, being the first of its kind, focuses on quantifying the actual economic contribution of nuclear technologies to economic development by evaluating the net benefit of the nuclear power with respect to the country's Gross Domestic Product (GDP). An input-output analysis was employed as a methodological approach to analyze inter-industrial economic activities by calculating the industrial value added as a means of the economic contribution during the period of 1980 to 2005. The industrial value added of nuclear technologies was estimated from the construction and operation of nuclear power (backward-linked industrial value added) and from the industrial activities attributed to the electricity generated by the nuclear power (forward-linked industrial value added). It was found that the total net contribution of nuclear technologies as a percentage share of GDP amounted to 2.38% in 2005.

ASIAA EXTRAGALACTIC STUDY WITH THE SMA

  • MATSUSHITA SATOKI;MAO RUI-QING;MULLER SEBASTIEN;CHOU CHUEN- YI;SAWADA-SATOH SATOKO;TRUNG DINH-VAN;LIM JEREMY;HSIEH PEI-YING;PECK ALISON B.
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.169-172
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    • 2005
  • We present CO(3-2), CO(2-1), and 230 GHz (1.3 mm) continuum images of nearby galaxies taken with the Submillimeter Array (SMA). Our main topic is to study the relation between higher-J molecular gas (e.g., CO J=3-2, 2-1) and nuclear activities (e.g., active galactic nuclei [AGNs] and starbursts). The nearby Seyfert 2 galaxy M51 shows strong CO(3-2) emission from the circumnuclear molecular gas, with an intensity twice as strong as that of the CO(1-0) emission. Strong CO(3-2) emission enhancement suggests that the circum nuclear molecular gas in M51 is warm and dense, which may be related to the AGN activities. Molecular gas in the nearby moderate starburst galaxy NGC 6946 is distributed along the large-scale bar or spiral arms and along the minibar, and the multi-J CO line images show very similar distribution to each other. For this galaxy, there is no clear enhancement in higher-J lines as seen in M51, which may be because NGC 6946 does not have clear AGN activities. Based on the results of these two galaxies, the physical conditions of the circum nuclear molecular gas may be related to the AGN activities. We also observed the nearby edge-on starburst galaxy NGC 3628 and the starburst/Seyfert composite galaxy NGC 4945 with the CO(2-1) line and 230 GHz (1.3 mm) continuum emission. These information will give us some hints for understanding the relation between nuclear activities and circum nuclear molecular gas and dust.

COMBINED ANALYTICAL AND EXPERIMENTAL INVESTIGATIONS FOR LWR CONTAINMENT PHENOMENA

  • Allelein, Hans-Josef;Reinecke, Ernst-Arndt;Belt, Alexander;Broxtermann, Philipp;Kelm, Stephan
    • Nuclear Engineering and Technology
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    • v.44 no.3
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    • pp.249-260
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    • 2012
  • Main focus of the combined nuclear research activities at Aachen University (RWTH) and the Research Center J$\ddot{u}$lich (J$\ddot{U}$LICH) is the experimental and analytical investigation of containment phenomena and processes. We are deeply convinced that reliable simulations for operation, design basis and beyond-design basis accidents of nuclear power plants need the application of so-called lumped-parameter (LP) based codes as well as computational fluid dynamics (CFD) codes in an indispensable manner. The LP code being used at our institutions is the GRS code COCOSYS and the CFD tool is ANSYS CFX mostly used in German nuclear research. Both codes are applied for safety analyses especially of beyond design accidents. Focal point of the work is containment thermal-hydraulics, but source term relevant investigations for aerosol and iodine behavior are performed as well. To increase the capability of COCOSYS and CFX detailed models for specific features, e.g. recombiner behavior including chimney effect, building condenser, and wall condensation are developed and validated against facilities at different scales. The close connection between analytical and experimental activities is notable and identifying feature of the RWTH/J$\ddot{U}$LICH activities.