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Volume 16, Issue 6
Displaying 1-11 of 11 articles from this issue
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Hajime YAMAMOTO, Isao SUMIDA, Shigeru IZUMI, Norihiko SAGAWA1979 Volume 16 Issue 6 Pages 383-389
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSPrecipitation rates of sodium impurities on orifices of a plugging indicator and dis-solution rates of precipitated impurities into sodium were studied to improve determina-tion accuracy of the plugging and unplugging temperatures measured by the indicator. Precipitation rates, obtained from decreasing sodium flow rates and orifice temperature, are proportional to the 0.8 power of the Reynolds number and to the square of the super-saturated concentration below 10 ppm. Dissolution rates, determined from increasing sodium flow rates and orifice temperature, are proportional to the 0.8 power of the Rey-nolds number and to the subter-saturated concentration below 10 ppm.
An analytical model, using the precipitation and dissolution rates, describes well the differences between cold trap temperature and the plugging and unplugging temperatures observed during periodical operations of the plugging indicator.View full abstractDownload PDF (415K) -
Kazuo SHIN, Yoshihisa HAYASHIDA, Seiji SHIROYA, Tomonori HYODO1979 Volume 16 Issue 6 Pages 390-400
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA Monte Carlo code was newly developed to examine response functions of a 2 in. dia. by 2 in. long NE-213 liquid scintillator for γ-rays. This code included the electron transport and the electron-photon cascade calculation to handle the wall and end effect induced by high energy electrons. Results of the Monte Carlo calculation were compared with measured values for standard sources, reaction γ-rays and thermal neutron capture γ-rays, and fairly good agreement was obtained.
Response functions for monoenergetic γ-rays of energies 110 MeV were calculated at 1 MeV intervals. The calculations were made in parallel incident geometry without the peripheral material components surrounding the scintillator. The results are tabulated in this paper. A response matrix calculated from the above data was applied to the unfolding of NE-213 pulse height spectra using the FERDO code and fairly good results were obtained in absolute values.View full abstractDownload PDF (600K) -
Takaaki MATSUMOTO1979 Volume 16 Issue 6 Pages 401-405
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSIt is necessary to correct the dynamical effect for obtaining the structure factor of liquids by the neutron diffraction method. The dynamical correction is so difficult for light nuclei that the neutron diffraction method has been prevented to be applied to various hydrogeneous liquids. The present paper describes the dynamical correction for light nuclei liquids in the case of the Time-of-Flight neutron diffraction method. The formulae of the correction consist of two seperative treatments in the high and low Q regions. The former is based on the Wick's short time approximation, whilist the latter is derived by the Placzek's inverse mass expansion method.View full abstractDownload PDF (234K) -
Makoto TAKANO, Yuichi OGAWA1979 Volume 16 Issue 6 Pages 406-415
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSStability is studied of a nuclear reactor system which is controlled by the concentra-tion change of poison solution circulating through the pipe installed in the reactor. Particular attention is paid to: (1) nonlinearities due to the reactivity feedbacks, (2) rigorous treatment of nonlinear control elements without employing approximate methods such as the describing function and (3) nonlinear characteristics of the concentration change of poison solution.
The stability of this complex reactor system is analyzed in the state space by apply-ing the technique based on Lyapunov's method. A special technique is employed to cope with the difficulty such that the stability of a system with time lag depends on the pre-sent state as well as on the past history of the state which is usually indeterminable. Analysis is carried out for both simplified and realistic models. For the former model, one stability region is compared with another by varying the lag time, characteristics of nonlinear elements and the power at equilibrium point. Similar results are also ob-tained for the latter model.View full abstractDownload PDF (599K) -
Tadayuki KATAOKA, Keishi MATSUMOTO1979 Volume 16 Issue 6 Pages 416-425
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe dynamical analysis was undertaken on the exchange of carbon taking place be-tween the structural steels and sodium for the case of a bi-metallic secondary system constituted of type 304 stainless and 21/4Cr-1Mo steels, representing the secondary system of a liquid sodium cooled fast breeder reactor. The analysis brought to light the effects to be expected on the long terms carbon transfer behavior of : (a) the surface areas of structural steels in contact with flowing sodium, (b) the thickness of the sodium-boundary layer, (c) the initial carbon concentration in the sodium, and (d) the rate of carbon contamination of the sodium.View full abstractDownload PDF (669K) -
Masumitsu KUBOTA, Isoo YAMAGUCHI, Haruto NAKAMURA1979 Volume 16 Issue 6 Pages 426-433
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDenitration with organic reductant such as formic acid is exclusively used for con-trolling acidity of the highly radio-active liquid waste (HLW) from nuclear fuel repro-cessing. This method, however, has a problem in suppressing a vigorous chemical reac-tion. The present study aimed at overcoming the disadvantage by the addition of nitrite to nitric acid solution before denitration.
As a result, the nitrite addition in the denitration of simulated HLW could reduce the induction period to almost zero and the maximum gas evolution rate to less than 60% of that obtained in the absence of nitrite. Effectiveness of nitrite addition was en-hanced especially for HNO3 concentration higher than 8 mol/l. The effective nitrite con-centration was over 0.01 mol/l in the reaction mixture.View full abstractDownload PDF (397K) -
Shoichi TACHIMORI, Akira SATO, Haruto NAKAMURA1979 Volume 16 Issue 6 Pages 434-440
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe distribution ratio Df and the separation factor β for Nd (III) to Am(III) were studied in DIDPA-DTPA systems to determine optimum conditions for applying DIDPA to the TALSPEAK type extraction process to separate transplutonides from lanthanoids in the partitioning of high-level waste of nuclear fuel reprocessing.
Extraction of lanthanoids from 0.050.1 M DTPA-1 M lactic acid (pH 3.0) aqueous solu-tion into 0.2-0.3 M DIDPA in DIPB gives the separation factor of 20 revealing practica-bility of this system in the partitioning. The nature of diluent affects greatly Df, and DIPB proved to be the most appropriate one for the separation of transplutonides from lanthanoids. The presence of lactic acid in the aqueous phase improved the extraction kinetics in DIDPA-DTPA system.View full abstractDownload PDF (384K) -
Shigeru IZUMI, Izumi YAMADA, Masayuki IZUMI1979 Volume 16 Issue 6 Pages 441-445
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA vibration monitoring technique has been developed which can be applied to con-tinuous monitoring and to patrol checking of many kinds of rotating machines in nuclear power plants. In this method, the vibrating condition in such equipment are represented in terms of two parameters, i.e. a vibration amplitude (RMS value) and an average fre-quency. The average frequency is defined as the root value of the second moment of the vibration frequency weighted by the power spectrum. The average frequency can be calculated by simple analogue circuits and does not need the spectrum analysis. Using these two parameter, not only the occurrence of abnormal vibration but also the type of vibration can be detected.View full abstractDownload PDF (252K) -
I. J. GUPTA, S. K. TRIKHA1979 Volume 16 Issue 6 Pages 447-449
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (201K) -
Ken YOSHIOKA, Kanji KATO1979 Volume 16 Issue 6 Pages 450-452
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (197K) -
Tatsuzo TONE1979 Volume 16 Issue 6 Pages 453-456
Published: June 25, 1979
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (270K)
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