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Volume 8, Issue 9
Displaying 1-10 of 10 articles from this issue
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Seiichiro YOKOTSUKA, Eiko AKATSU, Kaoru UENO1971 Volume 8 Issue 9 Pages 477-480
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSAqueous solutions of 131I and of 137Cs were passed through an ion exchange resin column. The resin bed consisted of a 2:1 mixture of cation and anion exchange resins, Diaion SKN-1 in H form and Diaion SAN-1 in OH form. The decontamination factors for these radioisotopes were determined at various flow rates, i. e., space velocities of 25∼200. The decontamination factor decreased with increasing flow rate for both radioisotopes. The Kd value of 137Cs between Diaion SKN-1 and water was about half that of 131I between Diaion SAN-1 and water, but D. F. of 131Cs was higher. Distribution of 137Cs in the resin column was also studied. Most of radioactivity was found at the top of the resin column.View full abstractDownload PDF (229K) -
Takashi NAKAMURA, Takashi KANAZAWA, Yo HAYASHI, Tomonori HYODO1971 Volume 8 Issue 9 Pages 481-491
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe spacial distributions of neutrons and photons have been studied in a cylindrical duct through a simulated iron-water multi-layered shield, filled with an iron plug on which six helical grooves had been cut at regular intervals and with pitches of 22, 44, 88 or 176cm.
The results obtained are discussed in relation to the three aspects of axial distribution, crosssectional distribution and streaming. It is shown that the axial distributions of the fast neutrons and photons accord with an exponential law, while those of the thermal and epithermal neutrons are the sum of two exponential functions. It has been found that the cross-sectional distributions of neutrons and photons have quite a sharp peak on the beam axis, indicating that the transmission through the duct is more important than the scattering and diffusion in the duct. The streaming effect along the helical grooves is not very marked in any of the cases, because of the large volume fraction of the iron plug to the total duct volume(79∼89%).View full abstractDownload PDF (1361K) -
Katsuhei KOBAYASHI, Tetsuo HASHIMOTO, Itsuro KIMURA1971 Volume 8 Issue 9 Pages 492-497
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe average cross section for the 232Th(n, 2n)231Th reaction to neutrons with the energy spectrum close to that of fission neutrons was obtained in the core of the Kyoto University Reactor, KUR. The value obtained was 12.5±0.84mb. This value agrees satisfactorily with Phillips' and with the calculated value obtained with the cross section in the U-K library and the Maxwellian fission neutron spectrum given by Leachman. A somewhat poorer agreement is seen with the calculated value obtained from Butler & Santry's cross section and Leachman's spectrum. The discrepancy amounts to 24 and to 39% respectively, for the average cross sections calculated with these two excitation functions and the fission neutron spectrum given by McElroy.
By making use of a Ge(Li) counter whose photopeak efficiency had been carefully calibrated, the absolute intensities were determined for eleven photopeaks observed on the γ-ray spectrum emitted by 231Th.View full abstractDownload PDF (420K) -
Tetsuhiko YOSHIMURA, Chie MIYAKE, Shosuke IMOTO1971 Volume 8 Issue 9 Pages 498-502
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe reaction of UO2 with CCl4 vapor was carried out in a vacuum of 10-5 mmHg at 500°C in order to prepare UCl4 of high purity. The lattice parameters were calculated from X-ray analysis to be a0=8.278±0.002, c0=7.460±0.009. The product thus ohtained was verified by chemical and X-ray analyses to be of anhydride form. The magnetic susceptibility was measured over the temperature range from liquid N2 to liquid He temperature, which revealed a deviation from the straight 1/X-T relation toward lower temperature.View full abstractDownload PDF (388K) -
Toshikazu TAKEDA, Tamotsu SEKIYA1971 Volume 8 Issue 9 Pages 503-512
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSA new method of calculating first-flight collision probabilities in cluster geometry is developed. The collision probabilities in an annular system as well as the transition probabilities for a neutron escaping from one subcell to reach other subcells are calculated and combined. The former is an improvement on Bonalumi's approximation and the latter is an extension of the Dancoff correction to subcells containing fuel rods and coolant. As applications of the present method, we calculate the collision probabilities in a hexagonal cluster with 7 fuel rods and in a square cluster with 28 fuel rods. Fairly good agreement is obtained by comparing the probabilities obtained from our method with the results obtained by the exact method. Onegroup calculations of the flux distribution are carried out in these systems.View full abstractDownload PDF (663K) -
Shingo TASHIRO1971 Volume 8 Issue 9 Pages 513-519
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe mechanism of skin contamination with radioactive materials was studied using protein film to simulate the human skin. The protein films were contaminated with 35S(H2SO4), 204Tl(TlNO3) and 147Pm(PmCl3), and many factors such as soiling time, radioactive concentration, specific activity and acidity of the soiling solutions, and the concentration of coexisting electrolytes were changed to examine their effect.
It is concluded that the protein film is a useful material for studying the mechanism of skin contamination with radioactive materials.
The contaminative behavior of the different radioisotopes on the film surface was found to reflect their respective properties, and varied accordingly.View full abstractDownload PDF (501K) -
Compaction of Sol-Gel UO2 Powder with a Pneumatic VibratorKaoru NARUKI1971 Volume 8 Issue 9 Pages 520-527
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSVibratory compaction was studied making use of a pneumatic vibrator to pack sol-gel UO2 powder in a thermal reactor type fuel canning tube. It is shown that the pneumatic vibrator utilized is superior to the commonly used electrodynamic vibrator from the view point of easy operation and high attainable density. Compared with the latter type, the pneumatic vibrator is less restrictive in the range of mesh size composing each fraction of the starting powder, and good results could be obtained with a powder with coarse, medium and fine fractions respectively having mesh ranges of 4∼6 (60%), 20∼65 (20%) and -200 (20%).
The selected operational conditions are: vibration frequency; 300 cpm, driving air pressure; 3kg/cm2 and duration of operation; 10min.
Fuel rods of 100cm length compacted in these conditions with sol-gel UO2 (particle density: 96% T. D.) attained a bulk density of 88.2±0.2% T. D. with an axial density distribution as uniform as ±3% T. D.View full abstractDownload PDF (1201K) -
Michio ICHIKAWA, Masaaki UCHIDA, Atsuyoshi MORISHIMA, Kiyoaki TAKETANI1971 Volume 8 Issue 9 Pages 528-530
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (207K) -
Yasunori YAMAMURA, Tamotsu SEKIYA1971 Volume 8 Issue 9 Pages 531-533
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (186K) -
Susumu FUKUSHIMA, Tatsuo SASAYAMA, Masayoshi KURIHARA, Junichi SHIMOKA ...1971 Volume 8 Issue 9 Pages 534-535
Published: September 25, 1971
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (118K)
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