• Title/Summary/Keyword: DORT

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Estimation of Radioactive Inventory for a major component of Reactor in Decommissioning (해체시 원자로 주요 구성품에 대한 방사능 재고량 평가)

  • Hak-Soo Kim;Ki-Doo Kang;Kyoung-Doek Kim;Chan-Woo Jeong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.1
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    • pp.69-75
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    • 2004
  • DORT and ORIGEN2 code were used for calculation of neutron flux and inventory in reactor pressure vessel(RPV) of Kori unit-1, To calculate neutron flux using DORT code, the reactor was divided into 94 mesh from the center of core to RPV and from 0 to 45 degree along the azimuth. The cross-sections of main nuclides were recalculated using neutron flux in the RPV region. The results showed that 95% of the total activity in RPV came from the nuclides of $^{55}$ Fe, $^{60}$ Co, $^{59}$ Ni and $^{63}$ Ni. And the total activity with cooling of more than 50 years after decommissioning was no more than 0.2% of at the time of shutdown. Considering the weight of RPV is 210 tons, the initial total activity of RPV reached 5.25${\times}$10$^{6}$ GBq. To verify results of ORIGEN2 calculation, comparison between calculated and measured value at RPV of Kori unit-1 was peformed. The comparison results showed a good agreement.

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Scaling theory to minimize the roll-off of threshold voltage for ultra fine MOSFET (미세 구조 MOSFET에서 문턱전압 변화를 최소화하기 위한 최적의 스켈링 이론)

  • 정학기;김재홍;고석웅
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.4
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    • pp.719-724
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    • 2003
  • In this paper, we have presented the simulation results about threshold voltage of nano scale lightly doped drain (LDD) MOSFET with halo doping profile. Device size is scaled down from 100nm to 40nm using generalized scaling. We have investigated the threshold voltage for constant field scaling and constant voltage scaling using the Van Dort Quantum Correction Model (QM) and direct tunneling current for each gate oxide thickness. We know that threshold voltage is decreasing in the constant field scaling and increasing in the constant voltage scaling when gate length is reducing, and direct tunneling current is increasing when gate oxide thickness is reducing. To minimize the roll off characteristics for threshold voltage of MOSFET with decreasing channel length, we know $\alpha$ value must be nearly 1 in the generalized scaling.

Scaling theory to minimize the roll-off of threshold voltage for nano scale MOSFET (나노 구조 MOSFET의 문턱전압 변화를 최소화하기 위한 스케일링 이론)

  • 김영동;김재홍;정학기
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.494-497
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    • 2002
  • In this paper, we have presented the simulation results about threshold voltage of nano scale lightly doped drain (LDD) MOSFET with halo doping profile. Device size is scaled down from 100nm to 40nm using generalized scaling. We have investigated the threshold voltage for constant field scaling and constant voltage scaling using the Van Dort Quantum Correction Model(QM) and direct tunneling current for each gate oxide thickness. We know that threshold voltage is decreasing in the constant field scaling and increasing in the constant voltage scaling when gate length is reducing, and direct tunneling current is increasing when gate oxide thickness is reducing. To minimize the roll-off characteristics for threshold voltage of MOSFET with decreasing channel length, we know u value must be nearly 1 in the generalized scaling.

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Evaluation of Neutron Flux Distributions of SMART-P IST Region for the Design of Ex-Core Detector (SMART 연구로 노외계측기 설계를 위한 IST 영역의 중성자속 분포 평가)

  • Koo, Bon-Seung;Kim, Kyo-Youn;Lee, Chung-Chan;Zee, Sung-Quun
    • Journal of Radiation Protection and Research
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    • v.30 no.2
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    • pp.55-60
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    • 2005
  • The evaluation of neutron flux distribution was performed for the ex-core detector design of SMART-P. DORT and MCNP code were used for the calculation of energy-dependent neutron flux distribution at 100% full power condition. Two code results show that maximum thermal flux appears at the $1^{st}$ water region in IST region and agree within 10% difference. In addition, another evaluation was performed code with assumptions that cote was composed of fission source and control rod without fuel assemblies. These assumptions make neutron count rate to be minimized. As a results, maximum thermal flux showed $6.99{\times}10^{-2}(n/cm^2-sec)$, when the strength of initial fission source was assumed as $1.0{\times}10^8(n/sec)$. The main reason of these results is due to the thermalization of fast neutrons in the water region and thermal flux is proportional to 80% of total neutron flux. Therefore, optimization of filler material of detector guide tube, position of installation and axial length of detector segments is necessary for the design of ex-core detector to enhance the neutron count rate and above results could be used in ex-core detector design as a fluence requirement.

고리원자력 4호기 감시시편 X에 대한 선량분석

  • 문복자;김형헌;김용일
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.125-130
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    • 1996
  • 최근 고리원자력 4호기 압력용기에 대한 제 3차 감시시험$^{(1)}$ 이 수행되었고 그 과정 중 측정된 시편에서의 반응률을 근거로 선량분석을 수행하였다. ENDF/B-VI를 근거로 만들어진BUGLE93$^{(2)}$ 라이브러리를 사용하여 각분할코드인 DORT version 2.7.3$^{(3)}$ 를 이용한 forward 및 adjoint 수송 계산 결과와 측정된 반응률을 결합하여 고리 4호기 원자로의 감시시편 X를 대상으로 1 MeV이상의 중성자속, 0.1 MeV 이상의 중성자속 및 dpa(displacement per atom)를 계산하여 측정치와 계산치를 비교하였다.

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