• Title/Summary/Keyword: radiation transport

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Surface Heat Budget of the Northern Sea of Cheju Island for June-August 1993 and 1994 (제주도 북부해역의 표면 열수지 해석 -1993년과 1994년 하계의 경우-)

  • 김해동;양성기
    • Journal of Environmental Science International
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    • v.4 no.3
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    • pp.197-206
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    • 1995
  • Surface heat balance of the northern sea of Cheju Island for summer in 1993 and 1994 is analyzed using the observation data obtained by Marine Research Institute, Cheju National University. Each flux elements at the sea surface is derived from the marine meteorological reports with application of an aerodynamical bulk method for the turbulent heat fluxes, and empirical formulae for the long-wave radiation heat fluxes. The flux divergence of oceanic heat transport and the rate of heat storage in the ocean are estimated as residual. The features of the surface heat balance are mainly decided by the solar radiation flux and the latent heat flux for 199B. But the Bowen Ratios were large for 1993. This means that the sensible heat fluxes were nearly equal to the latent heat fluxes for 1993. In this period, mean flux divergence of oceanic heat transport is about 130 W/$m^2$.

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An Radiological Assessment Resulting from Accident during Transportation of Irradiated PWR Fuel (경수로형 조사후핵연료의 수송중 사고결과 평가)

  • Yoon, Yeo-Chang;Ha, Chung-Woo
    • Journal of Radiation Protection and Research
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    • v.13 no.2
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    • pp.88-94
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    • 1988
  • The radiological impacts due to transportation of irradiated PWR fuel by truck were assessed for incident-free and accident conditions with. the computer code INTERTRAN. The resulting collective doses exposure to different subgroups of the public and of the workers were determined. Resulting collective doses for crewman and the public sharing the transport link and living in a corridor on either side of the route are small. All attempts to quantify the risk from the transport suffer from a lack of good input data. It is in these areas that the most important advances can be made.

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RADIATION SHIELDING EVALUATION OF IP-2 PACKAGES FOR LOW- AND INTERMEDIATE-LEVEL RADIOACTIVE WASTE

  • Kim, Min-Chul;Choi, Jong-Rak;Chung, Sung-Hwan;Ko, Jae-Hoon
    • Nuclear Engineering and Technology
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    • v.40 no.6
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    • pp.511-516
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    • 2008
  • Korea Hydro & Nuclear Power Co., Ltd. (KHNP) developed new IP-2 packages to transport low- and intermediate-level radioactive waste (LILW) steel drums from nuclear power plants to a disposal facility in accordance with IAEA and Korean transport regulations of radioactive material. Radiation shielding evaluation of the packages was carried out to demonstrate compliance with the regulatory requirements for IP-2 packages of radioactive material. Dose rate limits of LILW drums contained in the packages were determined.

Establishment of calculation methodology and thermal analysis for the development of a water calorimeter

  • Kang, M.Y.;Kim, Junhyuck;Choi, H.D.
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2620-2629
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    • 2020
  • As an early stage in the development of a water calorimeter, this study established a computer simulation methodology for analyzing the thermal behavior of a water calorimeter based on radiation transport and energy deposition. As a result, this study developed a method wherein the energy deposition distribution, which is obtained by applying Monte Carlo methods in water calorimeters, is directly used as a heat source for the thermal analysis model. Based on the proposed method, heat transfer in a water vessel and the effect of thermistor self-heating were analyzed. Through an analysis of the water velocities with and without a water vessel, it was found that a water vessel can serve as a convection barrier. Furthermore, it was confirmed that when considering thermistor self-heating, the water temperature change at the thermistor location is 0.219 mK higher compared to that when the thermistor was not considered. Therefore, thermistor self-heating must be considered to analyze the thermal behavior of a water calorimeter more accurately.

Nuclides Transport Analysis and Dose Calculation Using Dynamic Model for Rice Ingestion Pathway (쌀 섭취경로에서 동적모델을 사용한 장반감기핵종의 거동해석 및 내부피폭 선량계산)

  • Lee, Chang-Woo;Choi, Yong-Ho;Hwang, Won-Tae;Lee, Jeong-Ho
    • Journal of Radiation Protection and Research
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    • v.17 no.2
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    • pp.15-23
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    • 1992
  • Transport behaviors of Cs-137 and Sr-90 were analyzed and ingestion doses were calculated using dynamic model for rice field-rice-man pathway. Cs-137 binding strongly to soil remain longer in rice field than Sr-90. Foliar deposition on rice plant during growing period is the main contamination mechanism.

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Experiments for the Characteristic Evaluation of Pollutant Transport in Tidal Influenced Region (조파역내 오염물 이동특성 평가 실험)

  • Park, Geon Hyeong;Kim, Ki Chul;Jung, Sung Hee;Suh, Kyung Suk
    • Journal of Radiation Industry
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    • v.4 no.4
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    • pp.391-395
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    • 2010
  • The characteristics for pollutant transport in tidal influenced area was investigated using tidal wave hydraulic scale model. Hydraulic scale model was composed of the tidal generator, attenuation area and channel. Also, wave height, current meter and conductivity meter were used with the measured instruments in hydraulic scale model. NaCl with a tracer was used to evaluate the advection phenomena under the different velocity profiles. The arrival time of the maximum concentration in the condition of the relatively fast velocity was measured about 30 seconds faster than ones in the conditions of low velocity. The measured concentrations of the tracer were shown in the detection points of the flow direction consecutively.

Investigation on Numerical Integration for Radiation Heat Transfer in Radiating Fluid (복사유체의 복사열전달 수치 적분에 관한 연구)

  • Han Cho Young
    • Journal of computational fluids engineering
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    • v.9 no.2
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    • pp.43-51
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    • 2004
  • Interaction between fluid flow and thermal radiation has received considerable attention due to its numerous applications in engineering field. In this case the thermofluid properties of radiating fluid vary with the variation of temperature field caused by absorption and emission of radiant heat. To analyze the radiation heat transfer in radiating fluid, the simultaneous solution of the radiative transfer equation (RTE) and the fluid dynamics equations is required. This means that the numerical procedure used for the RTE must be computationally efficient to permit its inclusion in the other submodels, and must be compatible with the other transport equations. The finite volume method (FVM) and the discrete ordinates method (DOM) are usually employed to simulate radiation problems in generalized coordinates. These two representative methods are examined and compared, especially in view of the numerical integration of the radiation intensity over solid angle. The FVM shows better accuracy than the DOM owing to less constraints of the selection of control angle.

Investigation on Numerical Integration for Radiation Heat Transfer in Radiating Fluid (복사유체의 복사열전달 수치 적분에 관한 연구)

  • Han Cho Young
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.62-70
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    • 2004
  • Interaction between fluid flow and thermal radiation has received considerable attention due to its numerous applications in engineering field. In this case the thermofluid properties of radiating fluid vary with the variation of temperature field caused by absorption and emission of radiant heat. To analyze the radiation heat transfer in radiating fluid, the simultaneous solution of the radiative transfer equation (RTE) and the fluid dynamics equations is required. This means that the numerical procedure used for the RTE must be computationally efficient to permit its inclusion in the other submodels, and must be compatible with the other transport equations. The finite volume method (FVM) and the discrete ordinates method (DOM) are usually employed to simulate radiation problems in generalized coordinates. These two representative methods are examined and compared, especially in view of the numerical integration of the radiation intensity over solid angle. The FVM shows better accuracy than the DOM owing to less constraints of the selection of control angle.

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RADIATION HEAT TRANSFER IN HORIZONTAL CYLINDRICAL ANNULUS (수평원관 사이 환상유로에서의 복사열전달 연구)

  • Han, C.Y.;Park, E.S.;Jeon, H.Y.;Yu, M.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.75-77
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    • 2011
  • Thermofluid flow analysis is major subject in most computational fluid dynamics applications. Accompanying convective and conductive heat transport phenomena, radiation plays an important role in high temperature operating systems. Cares in which the radiation dominates are found in such systems as boilers, furnaces, rocket engines, etc. In this paper the finite-volume method (FVM) are employed to simulate two-dimensional radiation problems in concentric and eccentric horizontal cylindrical annuli with general body-fitted coordinates. In that case the simplest and intuitive remedies are proposed for mitigation of ray effect.

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Shielding analyses supporting the Lithium loop design and safety assessments in IFMIF-DONES

  • Gediminas Stankunas ;Yuefeng Qiu ;Francesco Saverio Nitti ;Juan Carlos Marugan
    • Nuclear Engineering and Technology
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    • v.55 no.4
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    • pp.1210-1217
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    • 2023
  • The assessment of radiation fields in the lithium loop pipes and dump tank during the operation were performed for International Fusion Materials Irradiation Facility - DEMO-Oriented NEutron Source (IFMIF-DONES) in order to obtain the radiation dose-rate maps in the component surroundings. Variance reduction techniques such as weight window mesh (produced with the ADVANTG code) were applied to bring the statistical uncertainty down to a reasonable level. The biological dose was given in the study, and potential shielding optimization is suggested and more thoroughly evaluated. The MCNP Monte Carlo was used to simulate a gamma particle transport for radiation shielding purposes for the current Li Systems' design. In addition, the shielding efficiency was identified for the Impurity Control System components and the dump tank. The analysis reported in this paper takes into account the radiation decay source from and activated corrosion products (ACPs), which is created by d-Li interaction. As a consequence, the radiation (resulting from ACPs and Be-7) shielding calculations have been carried out for safety considerations.