Journal of Nuclear Science and Technology
Online ISSN : 1881-1248
Print ISSN : 0022-3131
9 巻, 12 号
選択された号の論文の11件中1~11を表示しています
  • Toshikazu TAKEDA, Tamotsu SEKIYA
    1972 年 9 巻 12 号 p. 697-704
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    The one-group anisotropic diffusion coefficient is calculated for slab and square lattice cells with use made of Benoist's formula. In utilizing the integral transport theory, only several collisions suffered by a neutron have hitherto been considered. In this paper, we adopt the integral theory and take into consideration the effect of an infinite number of collisions suffered by a neutron, this being made possible by solving simultaneous equations. Further, we consider the anisotropic scattering through the generalized first-flight collision probability. Then we estimate the fundamental and the additional terms in the Benoist formula for slab and square lattice cells.
  • Theory and Analysis of Experiment
    Kazuko YAMAMOTO, Kunitoshi KURIHARA, Masayoshi ISHIDA, Ken-ichi MATSUO ...
    1972 年 9 巻 12 号 p. 705-715
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    A multigroup method of calculation is presented for describing the neutron behavior in a clustertype fuel lattice. It solves the integral transport equation by a semi-analytical method proposed in a previous paper for calculating collision probabilities in the lattice of a clustered fuel element. Using only fundamental nuclear data, it gives space and energy dependent neutron flux. The method has been programmed for HITAC-5020F (computer code named CLUSTER-III).
    The accuracy of the method has been tested by comparing the calculation with the experiment described in Part (I) of this paper. The lattices are 28-pin clusters of UO2 or PuO2+UO2 fuel pins, with heavy- or light-water moderators and with light-water coolant containing varying void ratios. The quantities studied are micro-parameters, reaction distributions in energy and space, thermal disadvantage factors and the multiplication factors. It is found that the calculated results are generally in good agreement with experiment, typically within 10% for micro-parameters and thermal disadvantage factor, and within 1% for the multiplication factor.
  • Tomitaro ISHIMORI, Kaoru UENO, Kan KIMURA, Michio HOSHI, Masakatsu SAE ...
    1972 年 9 巻 12 号 p. 716-720
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    Thorium dioxide amounting to 1.3kg was irradiated for 241 days at an average neutron flux of 6×1010n/cm2•sec, and allowed to stand for 1.2yr. This cooling lowered the γ-activity of the irradiated ThO2 sufficiently to permit handling without special shielding. Nine milligrams of 233U were extracted with TBP in dodecane, and determined by α-ray counting. The mass ratio of the uranium isotopes obtained was determined by mass spectrometry. It was indicated that the 233U was contaminated with natural uranium.
  • Shizuo YAMASHITA
    1972 年 9 巻 12 号 p. 721-726
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    The step cascade with side flow is defined as a step cascade where uranium of lower assays than that from the final stage is withdrawn, and where also, in addition to the major feed, reprocessed spent uranium is introduced as minor feed. A method of calculation is proposed for finding the exact total flow rate of the stream entering the separators in a step cascade with side flow in steady state and without losses of uranium.
    Using this method of calculation, it is found that the separation factor of diffusers in the new gaseous diffusion plant to be established in the United States is about 1.0022. Moreover, the characteristics are revealed for a step cascade with side flow adopted for a plant treating the estimated amounts of enriched uranium necessary for and uranium discharged from pressurized and boiling water reactors in the nuclear power generating program of Japan in 1985. It has been disclosed from these results of calculation that the method presented here proposes useful means for a detailed design of the plant.
  • Katsuro TAKAHASHI, Yoichi FUJII-E, Tokuo SUITA
    1972 年 9 巻 12 号 p. 728-736
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    An account is given of experiments on incipient boiling pressure pulses imparted by liquid sodium, performed in a forced convection loop. The sodium is heated by direct current applied to the liquid metal itself in a vertical tube of 14.9mm inner diameter through which the medium pumped. The experiments were carried out with the following ranges:
    Input power: 6∼12kW, Pressure at condenser: 0.6∼1.0kg/cm2,
    Inlet temperature: 780°∼850°C, Flow rate: 1.0∼3.5l/min
    Typical pressure pulses registered during incipient boiling presented the form of damped oscillation. The initial pressure pulses were dependent on the location of boiling inception along the test section, the incipient boiling pattern and the degree of superheat. The initial pressure pulses observed were in the range of 0∼3.5kg/cm2. The pressure pulses increased with the degree of superheat, which ranged 0°∼150°C.
    The magnitudes of pressure pulses exceeded the saturation vapor pressure corresponding to the temperature of superheated liquid. Consideration of a simplified model indicated that, during incipient boiling, the pressure in the vapor phase oscillates while approaching asymptotically the saturation pressure.
  • 1972 年 9 巻 12 号 p. 736
    発行日: 1972年
    公開日: 2008/12/19
    ジャーナル フリー
  • Haruo NATSUME, Hirokazu UMEZAWA, Shuji OKAZAKI, Toshio SUZUKI, Tamotsu ...
    1972 年 9 巻 12 号 p. 737-742
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    A sequential ion-exchange separation method was developed for use in burnup measurements of nuclear fuels. Group separation by anion-exchange resin column with hydrochloric acid solutions containing small amounts of nitric acid and hydrochloric acid was followed by various cation and anionexchange processes. The heavy elements, such as U, Np and Pu, and some fission products selected as burnup monitors, such as Cs, Mo and Nd, could be sequentially and quantitatively separated from a sample taken from spent fuel. The recovery of these elements through the separation processes were examined. The sampling ratio of an aliquot in reference to the whole fuel specimen was determined by adding as sampling monitor a known amount of Cu to the sample during dissolution. The validity of the ion-exchange separation technique for routine analysis for burnup measurements is also discussed.
  • Yasuaki NAKAHARA
    1972 年 9 巻 12 号 p. 743-748
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
    A very useful formula for interpolating the thermal neutron scattering law in temperature intervals is derived by separating the scattering law into two factors, strongly and weakly dependent on temperature. The strong temperature dependence of the scattering law is characterized by Debye-Waller factors, which are found to increase almost linearly with temperature for most moderators. The Debye-Waller factor is approximated by a linear function of temperature with the proportional constant determined so as to give the exact scattering laws at the boundaries of the temperature interval.
    Our formula is applied to two typical moderators (graphite and light water) to demonstrate its effectiveness and accuracy. It is shown that interpolated values of the scattering law are accurate within experimental errors in the practical range of momentum and energy transfers of neutrons.
  • Fumio KIKUCHI, Yoshio ANDO
    1972 年 9 巻 12 号 p. 749-751
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
  • Hiroshi MOTODA
    1972 年 9 巻 12 号 p. 751-753
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
  • Nobuhiro TANATUGU, Yoichi FUJII-E, Tokuo SUITA
    1972 年 9 巻 12 号 p. 753-755
    発行日: 1972/12/25
    公開日: 2008/12/19
    ジャーナル フリー
feedback
Top