• 제목/요약/키워드: Multiplication Factor

검색결과 136건 처리시간 0.026초

Determination of the Neutron Effective Multiplication Factor for a PWR Spent Fuel Assembly

  • Heesung Shin;Ro, Seung-Gy;Kim, Gil-Soo;Hwang, Yong-Hwa;Kim, Ho-Dong
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.590-595
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    • 2003
  • An Exponential experiment system which is composed of a neutron detector, a signal analysis system and a neutron source, Cf-252 has been installed in order to experimentally determine the neutron effective multiplication factor for a PWR spent fuel assembly. The axial background neutron flux is measured in a preliminary performance test. From the results, the spacer grid position is determined to be consistent with the design specifications within a 2.3% relative error. The induced fission neutron for four of the assemblies is also measured by scanning the neutron source, Cf-252 or the neutron detector. The exponential decay constants have been evaluated by the application of the Poisson regression to the net induced fission neutron counts. The measured keffs determined on the basis of the exponential decay constants of Cl5 appeared to be 0.541, 0.540, 0.597 and 0.556, respectively, which are comparable with 0.55195$\pm$0.00232 of the MCNP calculation.

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핵분열(核分裂) 중성자(中性子)스펙트럼이 핵임계도(核臨界度)에 미치는 효과(效果) (Effect of Prompt Fission Neutron Spectral Formulae on Nuclear Criticality)

  • 노성기;민덕기;육근억;오희필
    • Journal of Radiation Protection and Research
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    • 제7권1호
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    • pp.56-60
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    • 1982
  • 핵분열(核分裂) 즉발중성자(卽發中性子)스펙트럼의 표현식(表現式)인 왓트식(式), 크란버그식(式) 및 멕스웰식(式)을 핵분열(核分裂)의 선원항(線源項)으로 취(取)하여 고디바계(系)와 제제벨계(系)의 유효증배계수(有效增倍係數)를 ANISN 전산(電算)코드로 산출(算出)하고 타(他) 연구자(硏究者)의 실험치(實驗値)와 비교(比較)해 보았다 .그 결과(結果) 실험치(實驗値)에 가장 가까운 값을 주는 것은 멕스웰식(式)으로 보였다. 이것은 곧 멕스웰식(式)이 핵분열(核分裂) 즉발중성자(卽發中性子)스펙트럼의 적절(適切)한 표현식(表現式)임을 의미(意味)한다.

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Geometry Optimization of Dispersed U-Mo Fuel for Light Water Reactors

  • Ondrej Novak;Pavel Suk;Dusan Kobylka;Martin Sevecek
    • Nuclear Engineering and Technology
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    • 제55권9호
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    • pp.3464-3471
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    • 2023
  • The Uranium/Molybdenum metallic fuel has been proposed as promising advanced fuel concept especially in the dispersed fuel geometry. The fuel is manufactured in the form of small fuel droplets (particles) placed in a fuel pin covered by a matrix. In addition to fuel particles, the pin contains voids necessary to compensate material swelling and release of fission gases from the fuel particles. When investigating this advanced fuel design, two important questions were raised. Can the dispersed fuel performance be analyzed using homogenization without significant inaccuracy and what size of fuel drops should be used for the fuel design to achieve optimal utilization? To answer, 2D burnup calculations of fuel assemblies with different fuel particle sizes were performed. The analysis was supported by an additional 3D fuel pin calculation with the dispersed fuel particle size variations. The results show a significant difference in the multiplication factor between the homogenized calculation and the detailed calculation with precise fuel particle geometry. The recommended fuel particle size depends on the final burnup to be achieved. As shown in the results, for lower burnup levels, larger fuel drops offer better multiplication factor. However, when higher burnup levels are required, then smaller fuel drops perform better.

J 하수 처리장 방류수 중 세균의 성장 거동 및 염소 소독 효율 고찰 (Study on Microorganism Multiplication Behavior and Efficiency of Chlorine Disinfection in the Sewage Effluent from J Municipal Waste Water Treatment Plant)

  • 이운기;이윤진;정규연
    • 공업화학
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    • 제19권1호
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    • pp.122-128
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    • 2008
  • 본 연구에서는 J 하수 처리장의 최종 방류수를 대상으로 종속영양세균의 증식과 수중 물리, 화학적 영향인자와의 관계를 고찰하였다. 하수 중의 용존 유기물질 농도는 종속영양세균의 성장과 가장 밀접한 관계를 보였다. 미생물의 영양원인 단백질, 지방, 전분, 섬유소, 팩틴의 분해 세균 분포를 파악한 결과 하수 중 단백질 및 지방세균의 비율은 전체의 81%로 가장 높았다. 종속영양세균은 연중 8월에 가장 높은 수치를 나타냈다. 하수 방류수에 대해 10 mg/L의 유리염소를 주입하여 15 min간 접촉시 THMs의 농도는 $71{\mu}/L$ (< $100{\mu}/L$- 먹는 물 수질기준)의 값을 나타내어 높지 않았다.

울금의 경정배양에 의한 기내번식 (In vitro Propagation using Shoot Tip Culture of Curcuma longa L.)

  • 최성규
    • 한국작물학회지
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    • 제48권6호
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    • pp.438-441
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    • 2003
  • 울금의 기내대량번식을 위한 경정배양에 알맞은 기본배지의 종류와 기내증식 및 생장에 미치는 식물생장조절제의 농도를 구명하고자 본 실험을 수행한 결과는 다음과 같다. 울금의 경정은 MS(Murashige and Skoog)기본배지에 치상한 경우 Wanspojen, LS, White 배지보다 shoot와 root의 형성율이 높은 경향이었다. 기내의 유식물체 생장은 오옥신(NAA 0.5-l.0 $\textrm{mg}/\textrm{l}$)과 사이토키닌(BA 1.0-5.0 $\textrm{mg}/\textrm{l}$) 혼용처리가 효과적이었다.

H.264 동영상 부호화를 위한 효과적인 주파수 영역 잡음 제거 (Efficient Transform-Domain Noise Reduction for H.264 Video Encoding)

  • 송병철
    • 방송공학회논문지
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    • 제14권4호
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    • pp.501-508
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    • 2009
  • 본 논문은 H.264 동영상 부호기를 위한 효율적인 주파수 영역 잡음 제거 기법을 제안한다. 각 변환 블록과 잡음 제거를 위해 변형된 곱셈 팩터 행렬를 내적하는 방식으로 Wiener filtering이 이루어진다. 구현 시 look-up table을 이용하면 제안한 방법에서의 곱셈 연산을 간단히 대신할 수 있기 때문에 필터링에 의한 연산량은 무시할 만하다. 또한, 실험 결과를 통해 제안한 방법이 H.264 부호기에서 두드러진 잡음 제거 성능을 보임을 알 수 있다.

On the Feasibility of Minor Actinides Transmutation in a Low Aspect Ratio Tokamak Fusion Reactor

  • Hong, B.G.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.311.2-311.2
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    • 2013
  • Transmutation characteristics of minor actinides in a transmutation reactor based on a Low Aspect Ratio (LAR) tokamak are investigated. One-dimensional neutron transport and burn-up calculation coupled with the tokamak systems analysis were performed to find the optimal system parameters. The dependence of the transmutation characteristics such as neutron multiplication factor, produced power and transmutation rate on an aspect ratio A in the range of 1.5 to 2.0 was investigated. By adding Pu239 in the transmutation blanket as a neutron multiplication material, it was shown that the one unit of the transmutation reactor based on the LAR tokamak producing fusion power of 150 MWth can destroy the minor actinides contained in the spent fuels produced from more than 19 units of l GWe PWRs with production of the power being in the range of 0.9 - 3.4 GWth.

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Excell 프로그램을 통한 치료선량(M. U) 계산 (Monitor Unit calculation through Excell program)

  • 임광채;조은주;조선행
    • 대한방사선치료학회지
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    • 제11권1호
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    • pp.28-32
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    • 1999
  • Verifying the treatment value(Monitor Unit) unnecessarily involves too many simple and repetitive calculation processes, that is, individual computation process using the data(PDD value, Scp Factor, SSD Factor, Tray Factor) on the data book. We intend to minimize the time required to check the Monitor Unit through computerized calculation. Using $^{\ast}(multiplication)$, /(division), +(sum), if function, among others, which are present in the Excell program, MS office program, the Monitor Unit was obtainable through A/P value, Scp Factor and PDD value, Wedge Factor. From the verification of the computations of Monitor Unit for 60 patients previously treated, we were able to obtain an error rate of ${\pm}0.028MU$. Computerized calculation of the Monitor Unit could save the burden of Technologist.

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Determination of Stress Intensity Factor $K_I$ from Two Fringe Orders by Fringe Multiplication and Sharpening

  • Chen, Lei;Baek, Tae-Hyun
    • 비파괴검사학회지
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    • 제27권6호
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    • pp.550-555
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    • 2007
  • Stress intensity factor is one of the most important parameters in fracture mechanics. Both the stress field distribution and the crack propagation are closely related to these parameters. Due to the complexity of actual engineering problems, it is difficult to calculate the stress intensity factor by theoretical formulation, so photoelasticity method is a good choice. In this paper, modified two parameter method is employed to calculate stress intensity factor for opening mode by using data from more than one photoelastic fringe loop. For getting accurate experiment results, the initial fringes are doubled and sharpened by digital image programs from the fringe patterns obtained by a CCD camera. Photoelastic results are compared with those obtained by the use of empirical equation and FEM. Good agreement shows that the methods utilized in experiments are considerably reliable. The photoelastic experiment can be used for bench mark in theoretical study and other experiments.

The fast DCT algorithm based on the new prime factor and common factor decomposition

  • Choi, Byeong-Ho;Kim, Jong-Uk;Suh, Ki-Bum;Chong, Jong-Wha;Bang, Gyo-Yoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.245-250
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    • 1992
  • In this paper, we present a nev algorithm for the fast computation of the discrete cosine transform(DCT). This algorithm consists of the three dimensional prime factor-decomposed algorithm(PFA) and three dimensional common factor-decomposed algorithm(CFA). We can compute N-point DCT for the number N decomposable Into three relative prime numbers using PFA and into three common numbers using CFA. We also show input and output index mapping for the three decomposition. it results in requiring fever multiplicaions than the previous algorithms. Particularly, for the large number N, it is more powerful in reducing the number of multiplication.

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