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Volume 3, Issue 11
Displaying 1-8 of 8 articles from this issue
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Yuichi OGAWA, Ikuo KAJI, Yasutomo OZAWA1966 Volume 3 Issue 11 Pages 455-464
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSA control to bring the state of a reactor system to equilibrium state in time optimum manner is discussed. Non-linear integral equations containing the effects of two kinds of internal feedback and delayed neutrons and also the effect of external control are adopted for the dynamic equations of the system. These equations are reduced to quasilinear (parametric) differential equations, on which the external control applies in the form of a combination of the control reactivity, its rate of change and its acceleration.
Pontryagin's Maximum Principle is applied to a quasilinear system, and several modes of optimum control patterns - nodal, focal, saddle and mixed - are obtained according to the nuclear and thermal properties, the thermal output of the reactor and magnitude of the control. Optimum control is obtained in the form of piecewise constant control referred to a new control parameter which consists of a linear combination of the control reactivity, its rate of change and its acceleration.View full abstractDownload PDF (684K) -
Kensuke SHIRAISHI, Tomomi MURATA1966 Volume 3 Issue 11 Pages 466-472
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThe electron microscope has been used to observe the behavior of He gas bubbles in neutron irradiated Al-Li alloys. In the case of high He concentration, the gas bubbles were observed as small white or black dots in specimens as irradiated. The bubbles initiated appreciable growth upon heating to 400 ?? . They precipitated preferentially along the subgrain boundaries and dislocations, as well as along the grain boundaries. The size of the bubbles, observed in a specimen heated to 550 ??, ranged from about 10 ?? to 1 μ.
The shape of the bubbles in the specimen heated to 400 ?? was hexagonal or octagonal in the two-dimentional projection and a polyhedral image of the larger bubbles was clearly observed. The number of planes that bound the polyhedral bubble increased with increasing temperature of heating. Spherical bubbles were also observed.View full abstractDownload PDF (1969K) -
Yoshikazu YOSHIDA, Hatsumi TATSUTA, Hiroshi RYUFUKU, Kyoshiro KITANO, ...1966 Volume 3 Issue 11 Pages 473-478
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSA practical method applicable to field monitoring with survey instruments is presented, which permits evaluation of the dose equivalent rate for neutrons, the spectrum of which is unknown but with energy ranging from epithermal to fast. The detectors employed consist of a BF3 proportional counter with paraffin moderators 6.5 cm and 1.0 cm thick, sheathed in 0.5 mm thick Cd, and a scintillation (ZnS and plastic) counter. The dose equivalent rate D(mrem/hr) of neutrons with a broad spectrum is determined from the equation D=DB+DS, where DB is the dose equivalent rate determined from the effective neutron flux and the effective neutron energy through the counting rates obtained with the BF3 proportional counter with paraffin moderators, and DS the dose measured with the scintillation counter, the sensitivity of which is nearly proportional to the dose equivalent rate for neutrons above 2 MeV. The error in evaluating the dose equivalent rate by the present method has been calculated to be at most 60% for typical neutron spectra, in the energy range from epithermal to 10 MeV.View full abstractDownload PDF (1071K) -
Itaru MICHIYOSHI1966 Volume 3 Issue 11 Pages 479-485
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThis paper deals with an analysis of heat transfer in laminar flow with uniform internal heat generation in a concentric annulus with uniform but different heat fluxes at the two wall surfaces. The Nusselt numbers at each wall surface are calculated upon analyzing the radial distribution of the fluid temperature.
It is shown that the Nusselt numbers are affected by the ratios of the radii as well as of the wall heat fluxes, and also by the internal heat generation. As a special case, the analytical results of heat transfer in the absence of internal heat generation are compared with Dwyer's and Lundberg, et al.'s theories.View full abstractDownload PDF (327K) -
Hideaki NISHIHARA1966 Volume 3 Issue 11 Pages 486-490
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSThis and the companion paper(1) deal with space-dependent boiling water reactor kinetics by the method of adiabatic approximation. In this paper, equations are derived for axially space-dependent BWR feedback kinetics. These equations are coupled to the neutron equations through adiabatic approximation.
The reactor is divided into a number of axial regions. Assuming a trapezoidal distribution of the void and the water velocity distributions along the axis, balance equations for energy and mass are integrated to yield the region-exit quantities. With other pertinent equations, a computer code is written.
Some numerical results for a sample BWR are presented in the companion paper.View full abstractDownload PDF (357K) -
Hidehiko MITSUI1966 Volume 3 Issue 11 Pages 491-495
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSDownload PDF (309K) -
1966 Volume 3 Issue 11 Pages 495
Published: 1966
Released on J-STAGE: April 21, 2008
JOURNAL FREE ACCESSDownload PDF (48K) -
Hikaru ITOH, Yumi AKIMOTO, Bumpei ISHII1966 Volume 3 Issue 11 Pages 497-498
Published: November 25, 1966
Released on J-STAGE: February 28, 2008
JOURNAL FREE ACCESSDownload PDF (293K)
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