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Volume 23, Issue 1
Displaying 1-11 of 11 articles from this issue
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Manabu HAMASAKI, Toshikazu TAKEDA1986 Volume 23 Issue 1 Pages 1-10
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA fuel loading optimization method has been developed. The sensitivities of various performance parameters to loading pattern changes are calculated with depletion perturbation theory. With these sensitivities, the optimization problem is formulated by linear programming. This method has been applied to two test problems, and an improvement in the cycle burnup and the power peaking has been achieved. The accuracy of the present method has been checked by comparing the results with those obtained from direct burnup calculations.View full abstractDownload PDF (580K) -
Eishi IBE, Masaharu SAKAGAMI, Shunsuke UCHIDA1986 Volume 23 Issue 1 Pages 11-28
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSBased on a review of hydrogen injection test at BWRs, several possible factors were selected and studied to refine the radiolysis model previously proposed by the authors. The differences between calculated and measured dissolved oxygen concentrations were reduced 40% at low hydrogen concentration (<40 ppb) in reactor water by dividing the downcomer into several layers according to the dose rate, although some discrepancies still appeared at higher hydrogen concentrations. Emphasis was placed on the following items to provide more valid model analyses :
(1) Accurate measurements of rate constants at high temperatures (5285°C) are required for the following reactions :
H2+ OH H+ H2O, H2O2+ OH HO2+ H2O, and O2- + OH O2+ OH-.
(2) Impurities such as N2 and metal ions have a potential to curb efficiency of oxygen suppression by the hydrogen addition technique.View full abstractDownload PDF (1043K) -
Shingo MATSUOKA, Hirone NAKAMURA, Takaaki TAMURA, Takemi TAKANO, Yasuo ...1986 Volume 23 Issue 1 Pages 29-36
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe fixation operation was carried out at 450650°C, 1, 000 atm for 24 h. The amount of fixed Kr was measured using thermal neutron activation analysis. For zeolite-3A the amount of Kr fixed decreased from 20 to 5 % as the fixation temperature rose. In the case of zeolite-5A, Kr fixation was observed at 550°C and above, and the amount increased to 15 w/o as the temperature rose to 650°C. The diffusion coefficient of Kr in the zeolite was determined from the result of heating tests. The value obtained was substituted in a diffusion equation, enabling us to predict the Kr release behavior at any temperature in a dry atmosphere. Both the samples of zeolite-3A fixed below 525°C and of zeolite-5A below 625°C showed an intensive Kr release in water that would not be expected from the release behavior under dry conditions. However, such unexpected release was not observed in either sample fixed above these respective temperatures. This could be accounted for by the fact that zeolite cations move easily when zeolite is moisturized.View full abstractDownload PDF (590K) -
Katsuo ITO, Takuji KANNO1986 Volume 23 Issue 1 Pages 37-43
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSIt is necessary to investigate the effect of the denitration with formic acid on the precipitation behaviors of Ru and Tc from a simulated high-level liquid wastes, and the effect of the heat-treatments on the volatility behaviors of them from the sludges. The experiments were carried out using radiotracer techniques. Nitrosylruthenium ion was quantitatively converted into RuNO(OH)3 by the denitration at the initial molar ratio of (HCOOH) /(CNO3-) from 1.2 to 1.3, and the precipitation rate decreased drastically at the molar ratio over 1.5. Ferric ion was reduced to Fe2+ ion by the denitration. Pertechnetate ion was reduced to Tc02 by Fe2+ ion, and the quantitative yield of coprecipitation was achieved at the (HCOOH)/(NO3-) ratio above 1.8. The volatilities of Ru and Tc from the sludges increased with heating times and temperatures, however, decreased with an increase in the (HCOOH)/[NO3-] ratios. The denitration lowered the volatilization rate of Ru less than 4% at 1, 000°C for 3 h in an air flow. The volatilization rate of Tc was about 5% at 1, 000°C for 2h under conditions of the denitration of the (HC00H)/(NO3-) ratio over 1.8 and the heattreatment in an Ar flow.View full abstractDownload PDF (503K) -
Toshiyuki NAKAJIMA1986 Volume 23 Issue 1 Pages 44-52
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSAs an application of the twin filter TLD system, estimates of the quasi-effective energy of natural radiation were obtained at 43 monitoring points around nuclear power plants of eight prefectures in Japan. Quasi-effective energy was defined as energy corresponding to the effective energy of photon radiation determined using the half value layer method. The quasi-effective energy of natural radiation, except for the hard component of cosmic rays, was in the range of approximately 850 keV to 2.5 MeV, with 85% of all the monitoring points giving quasi-effective energies from 1.0 to 1.5 MeV. This result shows that the calibration source for natural radiation dosimeters must be a 60Co source.View full abstractDownload PDF (626K) -
Takenori SUZAKI, Shuji OKAZAKI, Hiroshi OKASHITA, Iwao KOBAYASHI, Tosh ...1986 Volume 23 Issue 1 Pages 53-72
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA non-destructive r-ray spectrometry technique was applied to 72 spent fuel assemblies discharged from the Japan Power Demonstration Reactor-I. The assemblies were dissolved at the Tokai Reprocessing Plant, and 19 batch-samples taken out of the dissolver vessels were subjected to detailed chemical analysis.
Burnups and Pu/U atom ratios were obtained from the non-destructively measured '"Cs activities and the 134Cs/37Cs activity ratios, respectively, by making reference to the correlations established in an experiment on fuel rods of a typical assembly in the core. The results were compared with those from chemical analysis, and a good agreement was found between the values obtained from the respective methods. A small deviation observed partly in the correlations was discussed in terms of the variation of spatial distribution of the fission-product activities in the individual assemblies.
Capability for the non-destructive method to estimate amounts of transuranium nuclides other than Pu was also discussed.View full abstractDownload PDF (1428K) -
Yukio SUDO, Keiichi MIYATA, Hiromasa IKAWA, Masanori KAMINAGA1986 Volume 23 Issue 1 Pages 73-82
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSExperiments were carried out with a vertical rectangular channel simulating a subchannel of the upgraded JRR-3 fuel element, in order to investigate the validity and the error of the correlations predicting the superheat at the onset of nucleate boiling. These correlations were used in the core thermal-hydraulic design of the upgraded JRR-3. As the results, the following were made clear : (1) The existing Bergles-Rohsenow correlation gives a good prediction for the relationship of heat flux vs. superheat at the onset of nucleate boiling, with the error of about 1 K against the lower limits of the measured superheat.(2) There are no significant differences in the characteristics of the relationship of heat flux vs. superheat at the onset of nucleate boiling between upflow and downflow. (3) There are no significant differences in the histories of relationship of heat flux vs, superheat from the forced convection single-phase flow to the subcooled boiling between increasing heat flux and decreasing heat flux, with little overshoot of superheat at the onset of nucleate boiling both in the upflow and in the downflow.View full abstractDownload PDF (800K) -
Yoshihiro KIKUCHI1986 Volume 23 Issue 1 Pages 83-85
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (231K) -
Takao OI, Tatsuya WATANABE, Hidetake KAKIHANA1986 Volume 23 Issue 1 Pages 86-88
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (262K) -
Tomitaro ISHIMORI, Masatomi SAKAMOTO, Koji TANAKA1986 Volume 23 Issue 1 Pages 89-91
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (226K) -
Tokio FUKAHORI, Yukinori KANDA, Hiroki TOBIMATSU, Yoshifumi MAEDA, Koj ...1986 Volume 23 Issue 1 Pages 91-93
Published: January 25, 1986
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (240K)
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