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Volume 2, Issue 11
Displaying 1-9 of 9 articles from this issue
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Takehiko YASUNO1965 Volume 2 Issue 11 Pages 427-431
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSEffective cadmium cutoff energies were calculated for 239Pu, 235U, 115Ir Au, 191Ir and 176Lu as a function of the cadmium filter thickness, the most probable energy of the Maxwellian flux and the epi-thermal index. An infinite slab geometry and isotropic flux were assumed in the calculations.
The calculated values of the cutoff energies are compared with those for 1/V detector, and are related to the resonance energies near the cutoff energy. If the resonance energy is lower than that of the 1/V detector, and the neutron spectrum and filter are same, the cutoff energy is lower than that of the 1/V detector. Such cases include 235U and 176Lu with thin filter, 191Ir with thick liter, and 239Pu with either thin or thick filter. If the resonance energy is higher than the Ec, of the 1/V detector, the cutoff energy is higher, such cases being 191Ir with thin filter, 176Lu with thick filter and 115In with either thin or thick filter. And if the resonance energy is very much higher than the Ec of the 1/V detector, as in the case of Au with thin filter, the cutoff energy approaches the value of the 1/V detector.View full abstractDownload PDF (282K) -
The Fluorination of Uranium MonocarbideMatae IWASAKI, Tsutomu SAKURAI, Jiro ISHIKAWA1965 Volume 2 Issue 11 Pages 432-437
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThe rate of the fluorination reaction of UC with fluorine to form UF6 has been studied in the temperature range between 240°and 300°C by following with a thermobalance the change in weight of the solid phase. The overall reaction takes place in two steps: In the first step, UC is rapidly converted to UF4, which, in the second step, fluorinates to UF6. During the first step, polymeric fluorocarbon is also produced and is found dispersed throughout the intermediate UF4 particles. At reaction temperatures below 270°C, the second step reaction roughly follows the linear law. At temperatures above 270°C, it comes to follow the parabolic law, presumably due to the formation of a compact layer of polymeric fluorocarbon on the surface of the particles. Analysis of the gaseous products using mass and infrared spectrophotometers revealed the formation of several kinds of lower fluorocarbons.View full abstractDownload PDF (538K) -
Keisuke KOBAYASHI, Masayuki FUKAO, Shojiro MATSUURA, Makoto UEDA1965 Volume 2 Issue 11 Pages 438-444
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThermal neutron distribution in a square lattice of water moderated UO2 (enriched to 2.596 W/0 in 235U) was measured with dysprosium micro-foils. Diameters of the fuel pellet and the aluminum cladding tube were 12.5 mm and 14.12 mm respectively. The pitch of the square lattice was 19.56 mm, and the water to fuel volume ratio 1.844. To obtain the integrated flux in the fuel and moderator regions, the solution for the p-1 diffusion equation was used. A disadvantage factor of 1.27±0.02 and a thermal utilization factor of 0.891±0.002 were obtained. The theoretical value of the disadvantage factor obtained by the 30 group integral transport theory in a square cell is 1.341 and is larger than the experimental value by a discrepancy exceeding the experimental error. The result is also compared with some approximate calculations.View full abstractDownload PDF (481K) -
M.H. MCKAY, A. KEANE, J. P. POLLARD1965 Volume 2 Issue 11 Pages 445-449
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSBy using a different approximation to the slowing down density, the accuracy of the effective resonance integral proposed by McKay(1) is extended to very dilute mixtures of an absorber with a moderator. The new formula is applied to the 6.68eV resonance of 238U and the 1.054eV resonance of 240Pu, to give results in excellent agreement with "exact" calculations for mixtures of various dilutions at 0°K and 900°K.View full abstractDownload PDF (301K) -
Ryukichi NAGASAKI, Kensuke SHIRAISHI1965 Volume 2 Issue 11 Pages 450-456
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSBending fatigue tests were carried out at room temperature on Magnox AL80 of different grain size specimens as well as on welded specimens. Also, the structure of the surface of the fatigue fractured specimens was examined. The fatigue strength of the fine-grained specimens was much larger than that of the coarse-grained. The fatigue behavior of the welded specimens was not appreciably different from that of the fine-grained specimens, although the S-N curves for these specimens were slightly different. In the fine-grained specimens, the fatigue cracks nucleated in the slip striations within the grains and propagated intergranularly for the most part. In the coarse-grained specimens the cracks propagated along slip bands within the grains or along the grain boundaries.
The irradiation effect on the fatigue properties of Magnox AL80 was also investigated. The fatigue resistance of the fine-grained specimens, including the welded specimens, was lowered by irradiation to an exposure of l×1017nvt when tested at high stress levels ; conversely, that of coarse-grained specimens was raised.View full abstractDownload PDF (624K) -
Shigeru YAMAGISHI, Yuichiro KAMEMOTO1965 Volume 2 Issue 11 Pages 457-462
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThe separation of fission products from irradiated UO2 in fused nitrate systems was studied by the following procedure:
Dissolution of UO2 in fused NH4NO3; adsorption of fission products on glass powder; fused salt chromatography with γ-Al2O3; evaporation from fused nitrates; and precipitation of U-compound (probably alkali uranate, M2U2O7) in a fused LiNO3-KNO3 mixture. Radiochemically pure Zr-Nb was selectively separated from the fused NH4NO3 melt by adsorption. Ru and I were completely evaporated from fused LiNO3-KNO3 mixture at above 280°C and from fused NH4NO3 at above 240°C, respectively. By means of chromatography with a γ-Al2O3 column, Zr-Nb and rare earths were completely separated from U in fused NH4NO3 or fused NH4NO3-LiNO3 medium at 150°to 180°C, and further, Cs, Ba and Ru were also expected to be separable from U under suitable condition. When the U-compound was precipitated in fused LiNO3-KNO3 at 350°C, Cs, Sr, Ba and Ru were fairly well separated from U.View full abstractDownload PDF (435K) -
Effect on the Extraction Behavior of Thorium and ProtactiniumTakehiko ISHIHARA, Yoshihide KOMAKI1965 Volume 2 Issue 11 Pages 463-467
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSRadiation damage to 5v/o alkyl amine/kerosene modified with lauryl alcohol was studied for changes brought thereby in their behavior in Th and Pa extraction by scrubbing with 3N nitric acid, and stripping with 0.01 N nitric acid at 25°C.
Eight amines were used; Tri-n-octyl amine, N-cyclohexyl dilauryl amine, N-benzyl dilauryl amine, N-cyclohexyl lauryl amine, Dilauryl amine, Amberlite LA-1, Amberlite LA-2 and Primene JM-T. These solvents were used virgin as well as irradiated by 60Co γ-ray to various doses up to 108R. No marked changes in extraction-scrubbing-stripping behavior were observed in all the amines tested, except N-cyclohexyl lauryl amine and Dilauryl amine, which tended to form either third phase or emulsion.View full abstractDownload PDF (322K) -
Itaru MICHIYOSHI, Ryiiichi MATSUMOTO1965 Volume 2 Issue 11 Pages 468-475
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThis paper deals with an analysis of heat transfer by slug flow in an annulus with different heat fluxes at the two wall surfaces. The local Nusselt numbers at each wall surface are calculated upon analyzing the radial distribution of the fluid temperature.
The local Nusselt number varies with the ratios of the radii as well as of the wall heat fluxes. The beat transfer in a circular tube and between two parallel plates are also discussed. As a special case, the present results agree very well with Dwyer's obtained for the heat transfer between two wall surfaces.View full abstractDownload PDF (431K) -
Shigeru HAYAKAWA, Kiyoshige ECHIKAWA1965 Volume 2 Issue 11 Pages 476-477
Published: 1965
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSDownload PDF (101K)
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