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Volume 21, Issue 1
Displaying 1-11 of 11 articles from this issue
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Masayoshi KANNO1984 Volume 21 Issue 1 Pages 1-9
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe growth rate of the energy demand in the world has been lowered recently, however, the essenciality of the development of nuclear power generation has not been changed. Because of the limited resources of terrestrial uranium, the techniques of the extraction of uranium from sea water as the practically unlimited resources of uranium have been devel-oped in Japan and other countries like F. R. Germany, Sweden, United States and others. Many fundamental results in the above field have been accumulated as well as some design studies and cost estimations have been conducted. In the last October, the International Meet-ing on Recovery of Uranium from Seawater was held in Japan organized by AESJ and IAEA. At this time moment, the up-to-date status of the studies including the selection of the chemical processes, development of adsorbents, design studies and cost estimations will be reviewed.View full abstractDownload PDF (669K) -
Shungo IIJIMA, Tadashi YOSHIDA, Tamotsu AOKI, Takashi WATANABE, Makoto ...1984 Volume 21 Issue 1 Pages 10-20
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSNuclear level density parameters of fission product nuclei were determined in a consistent way with experimental neutron resonance data and level, scheme data. The composite level density formula of Gilbert & Cameron was used with a revised expression of spin cut-off factor. The systematic trends in the determined parameters were investigated in detail. In addition to the parameter systematics used hitherto, two new phenomenological systematics were proposed and discussed. These systematics were fully used to estimate the level densities of nuclei whose experimental data are lacking. Parameters of about 130 nuclei were determined to form an extensive data base for calculation of neutron cross sections of fission products.View full abstractDownload PDF (647K) -
Toshikazu TAKEDA, Hideki KAMIDE, Eiji WACHI1984 Volume 21 Issue 1 Pages 21-31
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA calculational method of diffusion and drift coefficients for asymmetric slab cells has been derived on the basis of the first-flight collision probability method. The calculated values of the diffusion and drift coefficients for the asymmetric cells used in the fast critical assembly ZPPR-9 are shown. Drift coefficients calculated based on the original Duracz method and Duracz' cell averaging method are numerically compared. Flux distributions for one-dimensional slab models composed of the asymmetric cells such that U-238 plates are bunched at the core center are calculated with and without drift coefficients. It is seen that the Duracz original drift coefficient has well predicted the flux dip at the core center caused by neutron capture in the U-238 plates in lower energy, but the Duracz cell averaged drift coefficient is not able to predict the flux dip.View full abstractDownload PDF (690K) -
Yukio SUDO1984 Volume 21 Issue 1 Pages 32-41
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe present study investigates the effects of predominant parameters on the downcomer penetration of emergency core cooling (ECC) water under a counter current flow in the downcomer during refill phase in PWR loss-of-coolant accidents.
As the results, the following were revealed:
(1) Dominant parameters which correlate best for PWR downcomer penetration of ECC water are (i) dimensionless superficial velocities j*sg and j*sl of upward gas and downward liquid, based on the gap of annulus downcomer flow channel S, (ii) aspect ratio W/S of circumferential length W to gap of downcomer S, and (iii) dimensionless superficial velocity J*f, IN of ECC water injected into the downcomer, based on the circumferential length W of downcomer.
(2) Especially, the aspect ratio W/S plays an important role for scaling up to a full scale.BR>(3) The correlation proposed in this study for both complete bypass and partial penetration of ECC water which is supplied to the downcomer gives much better prediction to the experimental results than those by previous studies which have not taken into account the effects of aspect ratio of annulus downcomer flow channel.View full abstractDownload PDF (663K) -
Sung Sik KIM, Tomoo KIRIHARA1984 Volume 21 Issue 1 Pages 42-55
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSMeasurements of creep by the indentation with Knoop indenter were performed for sintered UO2 pellets before and after irradiation and a non-irradiated single crystal with an applied load of 50 g. Room temperature creep of non-irradiated sinters included grain bound. ary sliding. The creep at the lowest dose (7.8 × 1014 fiss./cm3) also involved the grain boundary sliding, while no creep was observed after irradiation of 2.9 × 1015 fiss. /cm3. Ir. radiated sinters at a dose between 1.4 × 1016 and 1 × 1018 fiss. /cm3 yielded not only primary creep without the grain boundary sliding but also secondary creep, in which cracks were formed when a dose was less than 4.8 × 1017 fiss. /cm3. At a dose of 1 × 1018 fiss. /cm3 the enhanced secondary creep independent of the temperature between 100 and 150°C was observed.View full abstractDownload PDF (942K) -
Kenji ICHIMURA, Masao MATSUYAMA, Kuniaki WATANABE1984 Volume 21 Issue 1 Pages 56-60
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSAs a first step toward solving the problem of contamination by tritium affecting second-ary electron multipliers, the material used in a marketed multiplier was studied in respect of adsorption and desorption behavior, with application of thermal desorption spectroscopy.
It was found that the tritium adsorbed on the material was desorbed in large part in the form of tritiated water, generated by chemical reaction that combined adsorbed tritium with excess oxygen present on the material and in small part in the form of tritiated hydrocarbons produced by exchange reactions taking place between the tritium and hydrocarbons also found adsorbed on the material surface. It was further indicated that tritium desorption took place from two distinct kinds of adsorption/desorption sites. Effective removal from the material was obtained of the adsorbed tritium by heating in inert gas flow at 500°C for 6 h. If a longer heating time can be allowed, a lower heating temperature should be suffice for decontamination.View full abstractDownload PDF (345K) -
Toshihiko YAMANISHI, Masahiro KINOSHITA1984 Volume 21 Issue 1 Pages 61-70
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA preliminary experimental study was performed by using a cryogenic distillation column which has a small inner diameter (2cm). The column separated N2 and Ar at a total reflux operation mode. The experimental column simulates adequately some significant fea-tures of a hydrogen isotope distillation column. A significant result obtained is that the mesh of the wire holding the packings was required to be as large as possible and conically-shaped for avoiding the flooding. The dynamic column behavior predicted by computer-aided simulation is in very close agreement with the experimental observation. The HETP value was measured for Dixon Ring under a variety of vapor flow rates within the column. The measured value is approximately 5.5 cm. The over-all HETP value is almost independent of the vapor flow rate. However, if the vapor flow rate is excessively small, the HETP value for the upper half of the column differs slightly from that for the lower half.View full abstractDownload PDF (664K) -
Lithification of Silica PowderNakamichi YAMASAKI, Kazumichi YANAGISAWA, Satoshi KANAHARA, Mamoru NIS ...1984 Volume 21 Issue 1 Pages 71-73
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (272K) -
Kazushige NISHIZAWA, Hisashi WATANABE, Yasuhiro SHIMOBAYASHI, Mutsuaki ...1984 Volume 21 Issue 1 Pages 74-76
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (248K) -
Tsunetaka BANBA, Haruto NAKAMURA1984 Volume 21 Issue 1 Pages 77-79
Published: January 25, 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (283K) -
1984 Volume 21 Issue 1 Pages 79
Published: 1984
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (52K)
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