• Title/Summary/Keyword: 중성자차폐

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An Effect of Energy Group Structure and Weighting Spectrum at the Resonance Energy Region of Iron on Neutron Shielding Calculation (철의 공명에너지 영역의 에너지군구조 및 가중스펙트럼이 중성자 차폐계산에 미치는 영향)

  • Jung-Do Kim;Yukio Ishiguro
    • Nuclear Engineering and Technology
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    • v.17 no.2
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    • pp.129-135
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    • 1985
  • Effects of differences between fine- and broad-group structures and spectrum as a weighting function at the resonance energy region of iron on a neutron shielding calculation were analyzed with the ANISN code and ENDF/B-IV data. The problems analyzed are the broad-group effect, the effect for variation of iron thickness, and the effect of problem-dependent weighting spectrum. In order to verify the group data and method used, a calculational benchmark was performed with the continuous-energy Monte Carlo code VIM. The result was compared with the ANISN calculations using the fine- and broad-group data.

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Shielding Design of Shipping Cask for 4 PWR Spent Fuel Assemblies (PWR집합체 4개 장전용 수송용기의 차폐설계)

  • Kang, Hee-Yung;Yoon, Jung-Hyoun;Seo, Ki-Seog;Ro, Seung-Gy;Park, Byung-Il
    • Nuclear Engineering and Technology
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    • v.20 no.1
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    • pp.65-70
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    • 1988
  • A Shielding analysis of the shipping cask designed conceptually, of which shielding material are lead and resin, for containing 4 PWR spent fuel assemblies, has been made with the help of a computer code, ANISN. The shielding materials being used in the cask have been selected and arranged to minimize cask weight while maintaining an overall shielding effectiveness. Radiation source terms have been calculated by means of ORIGIN-2 code under the assumptions of 38,000 MWD/MTU burnup and 3-year cooling time. A calculation of gamma-ray and neutron dose rates on the cask surface and 1m from the surface has been done. It is revealed that the total dose rates under the normal transport and hypothetical accident conditions meet the standards specified.

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Neutron Streaming Analysis in 1300 MWe Pressurized Water Reactor Cavity (1,300 MWe 가압경수로 공동내에서의 중성자 흐름해석)

  • Kwon, Seog-Guen;Kim, Kyung-Eung
    • Journal of Radiation Protection and Research
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    • v.10 no.1
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    • pp.41-49
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    • 1985
  • Neutron Streaming analysis in 1300 MWe pressurized water reactor cavity was performed. In this calculation, the discrete ordinates transport codes, ANISN and DOT 3.5, and the Monte Carlo code, TRIPOLI-02 were used with the coupling code, DOTTRI. In this study IBM 3033 type computer was used. The calculated neutron fluxes and dose rates were compared with the measured data in a 900MWe pressurized water reactor cavity to show a good agreement, although some deviations in the results for each energy group were noticed. These results will be applied in the radiation shielding design of high capacity nuclear power reactors and, to the means of radiation protection in case of the reactor maintenance and the access of the reactor cavity.

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A study on the calculation of the shielding wall thickness in Medical Linear Accelerator (의료용 선형가속기 차폐벽의 두께 산정에 관한 연구)

  • Lee, Dong-Yeon;Park, Eun-Tae;Kim, Jung-Hoon
    • Journal of radiological science and technology
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    • v.40 no.2
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    • pp.281-287
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    • 2017
  • The purpose of this study is to calculate the thickness of shielding for concrete which is mainly used for radiation shielding and study of the walls constructed to shield medical linear accelerator. The optimal shielding thickness was calculated using MCNPX(Ver.2.5.0) for 10 MV of photon beam energy generated by linear accelerator. As a result, the TVL for photon shielding was formed at 50~100 cm for pure concrete and concrete with Boron+polyethylene at 80~100 cm. The neutron shielding was calculated 100~140 cm for pure concrete and concrete with Boron+polyethylene at 90~100 cm. Based on this study, the concrete is considered to be most efficient method of using steel plates and adding Boron+polyethylene th the concrete.

Study on Effective Shielding of Secondary Radiation Generated by High Energy Proton Accelerator (고 에너지 양성자 가속기에서 생성되는 2차 방사선의 효과적인 차폐에 관한 연구)

  • Bae, Sang-Il;Kim, Jung-Hoon
    • Journal of radiological science and technology
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    • v.43 no.5
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    • pp.383-388
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    • 2020
  • High-energy proton accelerators continue to be increasingly used in medical, research and industrial settings. However, due to the high energy of protons, a large number of secondary radiation occurs. Among them, neutrons are accompanied by difficulties of shielding due to various energy distribution and permeability. So In this study, we propose a shielding method that can shield neutrons most efficiently by using multiple-shielding material used as a decelerating agent or absorbent as well as a single concrete shielding. The flux of secondary neutrons showed a greater decrease in the flux rate when heavy concrete was used than in the case of ordinary concrete, and the maximum flux reduction was observed at the front position when using multiple shields. Multiple shielding can increase shielding efficiency more than single shielding however, As the thickness of the multiple shielding materials increased, the decline in flux was saturated. The mixture material showed higher shielding results than the polyethylene when using boron carbonate.

Radiation Shield Analysis for Spent Fuel Shipping Cask (핵연료 수송용기의 방사선 차폐해석)

  • Cho, Kun-Woo;Kim, Hee-Won;Kwon, Seog-Kun;Kwak, Eun-Ho;Moon, Philip-S.
    • Journal of Radiation Protection and Research
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    • v.10 no.2
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    • pp.148-154
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    • 1985
  • Radiation shield design for a shipping cask, KSC-1, was evaluated to verify that the cask can be used in the transportation of a spent fuel assembly discharged from KNU 5 & 6. Radiation source term of the spent fuel assembly was calculated with the computer program ORIGEN-79, QAD-CG, ANISN-KA and DOT 3.5 codes Were used in the shielding calculations and the nuclear cross section data needed was extracted from the DLC-23/CASK library. It is concluded that KSC-1 shipping cask satisfies the requirements specified in the relevant regulations under normal conditions of transport and under accident conditions in transport.

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Dose-Rates Evaluation on a Reinforced Hot Cell facility (핫셀시설의 방사선 안전성 평가)

  • 조일제;국동학;구정회;정원명;유길성;이은표;박성원
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.584-589
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    • 2003
  • The hot cell facility which is designed to permit safe handling of source materials with radioactivity levels up to 1,385 TBq, is planned to be built. To meet this goal, the facility is designed to keep gamma and neutron radiation lower than the recommended dose-rate in normally occupied areas. The calculations performed with QAD-CGGP and MCNP-4C are used to evaluate the proposed engineering design concepts that would provide acceptable dose-rates during a normal operation in hot cell facility. The maximum effective gamma dose-rates on the surfaces of the facility at operation area and at service area calculated by QAD-CGGP are estimated to be $2.10{\times}10^{-3}$, $2.97{\times}10^{-2}$ and $1.01{\times}10^{-1}$ mSv/h, respectively. And those calculated by MCNP-4C are $1.60{\times}10^{-3}$, $2.99{\times}10^{-3}$ and $7.88{\times}10^{-2}$ mSv/h, respectively The dose-rates contributed by neutrons are one order of magnitude less than that of gamma sources, and penetration and toboggan will be partly reinforced by lead shield.

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An Improved Proton Recoil Telescope Detector for Fast Neutron Spectroscopy

  • Chung, Moon-Kyu;Kang, Hee-Dong;Park, Tong-Soo
    • Nuclear Engineering and Technology
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    • v.5 no.3
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    • pp.191-201
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    • 1973
  • For fast neutron spectroscopy in MeV region, a recoil proton telescope detector was designed and constructed so as to increase in detection efficiency without appreciable deterioration in energy resolution by adopting a special type of recoil proton radiator which is a combination of a ring-shaped vertical radiator and a cone-shaped horizontal radiator at a certain geometry. A neutron stopper was built in the detector system to minimize the background due to direct exposure of the Si(Li) detectors to primary incident neutrons. The detection efficiency and the energy resolution calculated at various neutron energies and geometries are given and these characteristics of the detector system were tested by 14.1 MeV neutrons. As the calculation predicted, the relative detection efficiency in case of the combined radiator system is almost 2.2 times of that for a single, ring-shaped vertical radiator system. The calculated energy resolution is 3.7% FWHM, whereas the measured resolution was 3.9% which means resolution broadening of approximately. 30% was resulted by introducing a combined radiator system into the telescope. Increase in background less than 40% was also observed.

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