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Subekti, M.*; Kudo, Kazuhiko*; Nabeshima, Kunihiko; Takamatsu, Kuniyoshi
Atom Indonesia, 43(2), p.93 - 102, 2017/08
Reactor kinetics based on point kinetic model have been generally applied as the standard method for neutronics codes. As the central control rod (C-CR) withdrawal test has demonstrated in a prismatic core of HTTR, the transient calculation of kinetic parameter, such as reactivity and neutron fluxes, requires a new method to shorten calculation-process time. Development of neural network method was applied to point kinetic model as the necessity of real-time calculation that could work in parallel with the digital reactivity meter. The combination of TDNN and Jordan RNN, such as TD-Jordan RNN, was the result of the modeling approach. The application of TD-Jordan RNN with adequate learning, tested offline, determined results accurately even when signal inputs were noisy. Furthermore, the preprocessing for neural network input utilized noise reduction as one of the equations to transform two of twelve time-delayed inputs into power corrected inputs.
Yamauchi, Toshihiko
Japanese Journal of Applied Physics, 43(9A), p.6473 - 6474, 2004/09
Times Cited Count:0 Percentile:0(Physics, Applied)The output pattern of He-Ne laser that passes through the optical glass fiber bundle used for free electron laser etc. depends on the weight of load (modulation of transverse mode). The increment of pattern radius exponentially increases with the load. It is considered that the micro bending causes this increment. Next, the estimated delay time also exponentially increases with the weight of load, and the estimated delay time is the extent of pico-second.
Nakajima, Ken; Yanagisawa, Hiroshi; Miyoshi, Yoshinori
JAERI-Tech 2003-028, 31 Pages, 2003/03
We have tried to measure the power profile in the TRACY supercritical experiment with high accuracy by detecting epithermal neutrons. In order to measure the epithermal neutrons, a cadmium covered U fission chamber was used, and polyethylene, a neutron moderator, was set inside the cadmium to enhance the neutron detection efficiency. In addition, a lead shield was used to reduce the noise current due to gamma-rays. The measured results were compared with the ones using a thermal neutron detector, and it was found that the time delay effect in the thermal neutron detection, which was caused by the flight time of neutrons to reach the detector, distorted the power profile and reduced its peak value. The reduction ratio of peak power was about 4% for the relatively slow power change with the inserted reactivity of 1.5$, but it became over than 40% for the rapid power change with the reactivity of about 3$.
Tonoike, Kotaro; Miyoshi, Yoshinori; Kikuchi, Tsukasa*; Yamamoto, Toshihiro
Journal of Nuclear Science and Technology, 39(11), p.1227 - 1236, 2002/11
Times Cited Count:21 Percentile:77.32(Nuclear Science & Technology)Kinetic parameter of low enriched uranyl nitrate solution was measured by the pulsed neutron source method in the STACY. This measurement was repeated systematically over several uranium concentrations from 193.7 gU/ to 432.1 gU/. Used core tanks were two cylindrical tanks whose diameters are 600 mm and 800 mm and one slab tank which has 280 mm thickness and 700 mm width. In this report, experimental data such as solution conditions, critical solution level for each solution condition, subcritical solution levels where measurements were conducted, measured decay time constants of prompt neutron and extrapolated values are described as well as basic principle of the pulsed neutron source method. values were evaluated also by computation with the diffusion code CITATION in SRAC and the nuclear data library JENDL 3.2. Both experimental and computational values show good agreement.
Kanno, Ikuo
Review of Scientific Instruments, 61(1), p.129 - 137, 1990/01
Times Cited Count:11 Percentile:73.79(Instruments & Instrumentation)no abstracts in English
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Journal of Nuclear Science and Technology, 5(7), p.374 - 376, 1968/00
Times Cited Count:0no abstracts in English