• 제목/요약/키워드: Nuclear Reaction

검색결과 1,015건 처리시간 0.027초

Influence of nuclear data library on neutronics benchmark of China experimental fast reactor start-up tests

  • Guo, Hui;Jin, Xin;Huo, Xingkai;Gu, Hanyang;Wu, Haicheng
    • Nuclear Engineering and Technology
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    • 제54권10호
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    • pp.3888-3896
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    • 2022
  • Nuclear data is the basis of reactor physics analysis. This paper aim at studying the influence of major evaluated nuclear data libraries, CENDL-3.2, ENDF/B-VIII.0, JEFF-3.3, and JENDL-4.0u, on the neutronics modelling of CEFR start-up tests. Results show these four libraries have a good performance and consistency in the modelling CEFR start-up tests. The JEFF-3.3 results exhibit only an 8 pcm keff difference with the measurement. The difference in criticality is decomposed by nuclide, which shows the large overestimation of CENDL-3.2 is mainly from the cross-section of 52Cr. Except for few cases, the calculation results are within 1σ of measurement uncertainty in control rod worth, sodium void reactivity, temperature reactivity, and subassembly swap reactivity. In the evaluation of axial and radial reaction distribution, there are about 65% of relative errors that are less than 5% and 82% of relative errors that are less than 10%.

PCR법에 의한 잠실먼지 중 핵다각체병 바이러스의 검출 (Detection of Bombyx mori Nuclear Polyhedrosis Virus(BmNPV) in dust of Silkworm rearing room by PCR)

  • 남성희;한명세
    • 한국잠사곤충학회지
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    • 제39권1호
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    • pp.30-35
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    • 1997
  • A rapid and sensitive detection of BmNPV contamination in silkworm rearing room was carried by Plymerase chain reaction(PCR). Silkworm nuclear polyhedra were dissolved for the extraction of viral DNA within 30 minutes followed by the treatment of alkaline solution. The combination of primers of NP3 and NP2 was superior in PCR to the other 7 primers applied. Each primer was designed with 20 base in size and Newly designed NP3 of sense and the already reported NP2 for antisense were better in reaction than other primers. PCR products appeared 500bp in size. And annealing was confirmed proper at 55$^{\circ}C$ condition. Amplifiable template DNA amount was confirmed at least 100 ng to 0.1 ng and regarded as applicative for the assay of silkworm rearing environmental condition of sericultural farm. In case of the detection of BmNPV from the dust, sensitivity by PCR was as high as 1,000,000 times than that of microscopic observation.

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Calculation of Proton-Induced Reactions on Ti, Fe, Cu and Mo up to 60 MeV for TLA Application

  • Kim, Doohwan;Lee, Young-Ouk;Jonghwa Chang
    • Nuclear Engineering and Technology
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    • 제31권6호
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    • pp.595-607
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    • 1999
  • The reaction cross-sections of $^{nat}$Ti(p,X)$^{48}$ V, $^{nat}$Fe(p,X)$^{56}$ Co, $^{nat}$Cu(p,X)$^{65}$ Zn and $^{nat}$Mo(p,X)$^{96}$ Tc for TLA application are calculated in the frame of the ECIS-GNASH code system up to 60 MeV. The calculated results are compared with the experimental data taken from the EXFOR at the NEA Data Bank. A preliminary calculation with the global optical parameters of Varner et al. shows considerable differences from the experimental data at low energy range. The global optical parameters for the imaginary volume potential and the diffuseness of the imaginary potential are adjusted to achieve a better description of the experimental data in the vicinities of peak position below 16 MeV. 16 MeV.

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MODELING OF THE BAINITE TRANSFORMATION KINETICS IN C-MN-MO-NI STEEL WELD CGHAZ

  • Sangho Uhm;Lee, Changhee;Kim, Joohak;JunhwaHong
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.276-281
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    • 2002
  • A metallurgical model for bainite transformation kinetics in the coarse-grained heat affected zone(CGHAZ) on the basis of an Avrami-type equation was studied. Isothermal transformation tests were carried out to obtain the empirical equations for incubation time and Avrami kinetic constants for C-Mn-Mo-Ni steel. The effect of prior austenite grain size(PAGS) on the reaction rate of bainite was also investigated. Compared with experimental transformation behavior of bainite, the predicted behavior was in good agreement. It was also found that a smaller grain size retard the bainite reaction rate, contrary to the classical grain size effect and this is considered to be caused by constraint of grain size to bainite growth.

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원자력 극한환경용 세라믹 열교환기 소재로서 반응소결 SiC 세라믹스 제작성 (Fabricability of Reaction-sintered SiC for Ceramic Heat Exchanger Operated in a Severe Environment)

  • 정충환;박지연
    • 한국세라믹학회지
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    • 제48권1호
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    • pp.52-56
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    • 2011
  • Silicon carbide (SiC) is a candidate material for heat exchangers for VHTR (Very High Temperature Gas Cooled Reactor) due to its refractory nature and high thermal conductivity. This research has focused on demonstration of physical properties and mock-up fabrication for the future heat exchange applications. It was found that the SiC-based components can be applied for process heat exchanger (PHE) and intermediate heat exchanger (IHX), which are operated at $400{\sim}1000^{\circ}C$, based on our examination for the following aspects: optimum fabrication technologies (design, machining and bonding) for compact design, thermal conductivity, corrosion resistance in sulfuric acid environment at high temperature, and simulation results on heat transferring and thermal stress distribution of heat exchanger mock-up.

Rhenium-188 생산 (Production of Re-188)

  • 양승대;서용섭;김상욱;임상무
    • 대한핵의학회:학술대회논문집
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    • 대한핵의학회 1999년도 제38차 춘계학술대회
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    • pp.189-192
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    • 1999
  • $^{188}Re$ (${\beta}^-=2.2$ MeV; ${\gamma}^-$=155 keV; $T_{1/2}$=16.9 hours) is an attractive therapeutic radioisotope which is produced from decay of reactor-produced tungsten-188 parent ($T_{1/2}$=69 days). $^{188}W$ has been produced from the double neutron capture reaction of $^{186}W.\;^{188}Re$ can be easily obtained by elution of saline on alumina based $^{188}W/^{188}Re$ generator, which is commercially available. Complexes labelled with $^{188}Re$ have been developed for the radiotherapy treatment of diseases because of the desirable nuclear properties of the radioisotope and it's chemical properties similar to those of technetium, a well established diagnostic agent.

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A MODEL STUDY ON MULTISTEP RECOVERY OF ACTINIDES BASED ON THE DIFFERENCE IN DIFFUSION COEFFICIENTS WITHIN LIQUID METAL

  • CHUN, YOUNG-MIN;SHIN, HEON-CHEOL
    • Nuclear Engineering and Technology
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    • 제47권5호
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    • pp.588-595
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    • 2015
  • This study presents an effective method for additional recovery of residual actinides in liquid electrodes after the electrowinning process of pyroprocessing. The major distinctive feature of this method is a reactor with multiple reaction cells separated by partition walls in order to improve the recovery yield, thereby using the interelement difference in diffusion coefficients within the liquid electrode and controlling the selectivity and purity of element recovery. Through an example of numerical simulation of the diffusion scenarios of individual elements, we verified that the proposed method could effectively separate the actinides (U and Pu) and rare-earth elements contained in liquid cadmium. We performed a five-step consecutive recovery process using a simplified conceptual reaction cell and recovered 58% of the initial amount of actinides (U + Pu) in high purity (${\geq}99%$).

Kinetic Studies on Halogen Exchange Reactions of Phenethyl Chloride in Acetone

  • Kim, Shi-Choon;Cheun, Young-Gu;Sakong Yul
    • Nuclear Engineering and Technology
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    • 제7권1호
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    • pp.25-29
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    • 1975
  • 1-Phenethyl Chloride와 2-Phenethyl Chloride의 할로겐 교환반응 속도를 아세톤 용매속에서 방사성 할라이드 이온을 사용하여 측정하였으며, 활성화 엔탈피와 활성화 엔트로피를 결정하였다. 이 반응은 S$_{N}$2 반응이며 할라이드 이온의 상대적 친핵성의 순서는 Cl->Br->I-이고 반응 속도는 Benzyl Chloride와 비교해 볼때 대체적으로 느리다. 이 결과를 할라이드 이온의 용매화 효과와 HSAB원리로 설명하였다.

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Detector Foil Self-Shielding Correction Factors

  • Kwon, Oh-Sun;Kim, Bong-Ghi;Suk, Ho-Chun
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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    • pp.197-201
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    • 1996
  • In the detail reaction-rate measurements in a critical assembly using the foil activation method, the measured activations of detector foils have inevitably errors caused by detector foil self-shielding effect. If neutron flux could be approximated to Westcott flux: i.e. well thermalized Maxwellian distribution, these activations of detector foil could be corrected to represent the unperturbated flux at any detected position in the cell with using Westcott option and reaction-rate option of the lattice code, WIMS-AECL. These calculated detector material self-shielding correction factors of the tested fuel, CANFLEX provided much information about neutron spectrum of test lattice cell as well as the correction factors themselves. The results could be verified by another lattice calculations.

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