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Volume 18, Issue 10
Displaying 1-10 of 10 articles from this issue
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Makio OHKUBO, Yuuki KAWARASAKI, Motoharu MIZUMOTO1981 Volume 18 Issue 10 Pages 745-755
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSNeutron resonances of separated isotopes of bromine were measured using a TOF spec-trometer of the Japan Atomic Energy Research Institute electron linear accelerator. Trans-mission and capture measurements were made with a 6Li-glass and a Moxon-Rae detector respectively, on separated isotopes (98%) of 79Br and 81Br. Resonance analyses were made on transmission data with an area analysis code, and on capture data with a Monte-Carlo program. For 79Br gΓ0n values of 156 levels below 10 keV are obtained, and for 81Br 100 levels below 15 keV. The s-wave strength function S0, average level spacing <D>, and average radiation width <Γγ> are obtained ; for 79Br S0= (1.27 ± 0.14)10-4, <D>= 45 ± 5 eV, <Γγ>=293 ± 20 meV, and for 81Br S0= (0.86 ± 0.14) 10-4, <D> =70 ± 12 eV. <Γγ> = 234 ± 20 meV. For 79Br statistical properties of resonances are in good agreement with the predictions of the statistical model. Intermediate structures are observed in the resonances of 81Br show-ing clusters of levels at 1.2, 4.4, 10.0, 11.5 and 14.1 keV, where the curve of cumulative sum of gΓ0n vs. neutron energy shows steep rises.View full abstractDownload PDF (656K) -
Ritsuo OGUMA, Koji HAYASHI, Toshio KITAJIMA1981 Volume 18 Issue 10 Pages 756-765
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSModel identification technique based on ARX (autoregressive model with exogenous variable) process was applied to dewpoint data recorded at OWL-1 (Oarai Water Loop No. 1) loop cubicle in JMTR (Japan Materials Testing Reactor) and the dynamical interrelationship between the supply and exhaust dewpoints in the ventilation system of the cubicle was empirically determined.
It was shown that the information so derived on the dewpoint dynamics can assist to enhance the sensitivity of leak detection, if it was incorporated into a leak monitoring system for the OWL-1 loop.
A simple digital filter incorporating the dewpoint dynamics was designed in an attempt to develop an efficient leak monitor for the OWL-1 loop. This filter was applied to the dewpoint data recordings during an abnormal leak that had occurred at the OWL-1 loop in the 43 rd cycle of JMTR operation, which demonstrated the effectiveness of the present method for leak detection at its early stage.View full abstractDownload PDF (646K) -
Teruko SAWAMURA, Motoyuki NOMURA, Hatsuo YAMAZAKI, Yasutomo OZAWA1981 Volume 18 Issue 10 Pages 766-772
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSStudies are described on spark counting of tracks directly induced by fast neutrons in the cellulose nitrate detector, LR-115 (Type II). The spark counting for the detector ir-radiated by neutrons from an Am-Be source was performed under different etching condi-tions and different sample setting in the spark counter used in the experiment. The char-acteristic curves of spark counts vs. neutron fluence was determined, and sensitivity of the detector treated by the method was obtained to be 3×10-7 for the fluence between 1×107and 2×109 n/cm2 in the most adequate condition. The reproducibility of this method was estimated to be 13%.View full abstractDownload PDF (464K) -
Yoshiaki SHIMIZU1981 Volume 18 Issue 10 Pages 773-784
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA mathematical procedure is proposed to make a radioactive waste management plan comprehensively. Since such planning is relevant to some different goals in management, decision making has to be formulated as a multiobjective optimization problem. A mathema-tical programming method was introduced to make a decision through an interactive manner which enables us to assess the preference of decision maker step by step among the con-flicting objectives.
The reference system taken as an example is the radioactive waste management system at the Research Reactor Institute of Kyoto University (KUR). Its linear model was built based on the experience in the actual management at KUR. The best-compromise model was then formulated as a multiobjective linear programming by the aid of the computa-tional analysis through a conventional optimization. It was shown from the numerical re-sults that the proposed approach could provide some useful informations to make an actual management plan.View full abstractDownload PDF (730K) -
Masafumi NAKATSUKA, Yo HAYASHI1981 Volume 18 Issue 10 Pages 785-792
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSEffects of iodine on the cyclic tensile properties of Zircaloy-2 have been investigated at 350°C. Notched specimens, which were grooved circumferentially, and unnotched specimens were machined from the stress-relieved fuel cladding. Cyclic tensile stress was loaded on the specimens in order to get the fatigue life and failure ductility in air and in an Ar atmosphere containing iodine.
The fatigue life and failure ductility of the unnotched specimens, which were pulled parallel to the longitudinal direction of the cladding, showed little decrease due to effects of the iodine environment, though many pittings due to iodine corrosion were observed on the inner surfaces.
On the other hand, the fatigue properties of the notched specimens indicated the effects of iodine. This difference implies that the corrosion fatigue property of Zircaloy-2 fuel cladding under the iodine environment depends on the texture and stress state of the specimens.View full abstractDownload PDF (489K) -
Yoichi SAKUMA, Makoto OKAMOTO, Hidetake KAKIHANA1981 Volume 18 Issue 10 Pages 793-801
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA nearly ideal displacement chromatography has been realized with an eluent of MgSO4 and H2SO4 in the study of uranium isotope separation by means of cation exchange chroma-tography using uranous sulfate complexes. Uranium-235 was enriched at the end of the chromatogram and 238U was enriched at the front. Two long distance displacement ex-periments have been carried out, keeping an isotopic plateau region on the chromatogram. Consequently, good accumulation of the isotopic fractionation based on uranous-sulfate com-plex formation reactions obtained. The separation coefficient ε of this system was estimated to be about 5×10-5.View full abstractDownload PDF (574K) -
Teruo FURUTA, Hiroshi UETSUKA, Satoru KAWASAKI1981 Volume 18 Issue 10 Pages 802-810
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSUnder a LOCA transient in LWRs, ruptured Zircaloy clad tubes would be oxidized at the inner surface as well as outer surface by steam flowing in reactor core. In order to determine whether the inner-surface oxidation influences mechanical properties of clad tubes during the reflood stage of a LOCA, the ring compression tests were conducted on oxidized tube specimens and segments sectioned from ruptured claddings obtained from rod-burst/oxidation tests ranging from 1, 200 to 1, 500 K.
The degradation of the fracture load and the deflection at 373 K are largely influenced by the hydrogen absorption during the inner-surface oxidation. The oxidation temperature and the time dependence of the ductility loss of Zircaloy clad tubes can be represented by iso-deflection lines. The iso-deflection lines due to the hydrogen absorption limit the per-missible oxidation condition to a lower temperature and shorter period of exposure time, comparing with sole oxygen uptake.View full abstractDownload PDF (583K) -
Hiroaki TAGAWA, Takeo FUJINO, Kinji OUCHI, Kenju WATANABE, Takao MORIM ...1981 Volume 18 Issue 10 Pages 811-816
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe oxidation-reduction properties of mixed oxides in the system Sm-U-0 and the varia-tion of their lattice parameters due to oxidation and reduction were examined by means of thermogravimetry and X-ray diffraction. For mixed oxides SmyU1-yO2±x prepared in air, the O/M ratio decreased linearly from 2.667 at y=0 to nearly stoichiometric 2.02 at y=0.5. The O/M ratios at y>0.5 were on the line connecting 2.667 at y=0 with 1.50 at y=1. The single phase region of the fluorite structure was between y=0.5 and 0.6. The lattice parameters of the fluorite phase at y ?? 0.6 were constant, 5.418×10-10 m. For mixed oxides prepared in hydrogen, the O/M ratio decreased linearly from 2.00 at y=0 to 1.84 at y=0.5, and from 1.84 at Y=0.5 to 1.50 at y=1. The quenched oxides were single phase compounds except those for y=0.1, 0.6 and 0.9. The lattice parameter of the fluorite structure de-creased from 5.4700 at y=0 to 5.427×10-10 m of Sm0.4U0.6O1.854, and was kept constant be-tween y=0.4 and 0.5, then increased to 5.466 ×10-10 m at y=0.7. The Sm-U-O phase diagram at 1, 000°C was constructed on the basis of the X-ray diffraction work.View full abstractDownload PDF (400K) -
Masakazu YOSHIDA, Katsutoshi AZUMA, Kenji YAMAZAKI, Takeo NAWAI, Hiroy ...1981 Volume 18 Issue 10 Pages 817-819
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (189K) -
Akio MIYAKOSHI, Azuma O. UCHI, Ikuo KAJI1981 Volume 18 Issue 10 Pages 820-822
Published: October 25, 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (186K)
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