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Yoshida, Hiroshi*; Aoki, Takayuki*; Utsumi, Takayuki*
Denshi Joho Tsushin Gakkai Rombunshi, A, 86(3), p.223 - 231, 2003/03
no abstracts in English
Sakurai, Kiyoshi; Ueki, Kotaro*
Nihon Genshiryoku Gakkai-Shi, 43(4), p.351 - 352, 2001/04
no abstracts in English
Ando, Masaki; Iijima, Susumu; Okajima, Shigeaki; Sakurai, Takeshi; Oigawa, Hiroyuki
JAERI-Research 2000-017, p.36 - 0, 2000/03
no abstracts in English
; Kitada, Takanori*; Tagawa, Akihiro; ; Takeda, Toshikazu*
JNC TJ9400 2000-006, 272 Pages, 2000/02
Investigation was made on the follwing three themes as a part of the improvement of reactor physics analysis method for FBR with various core concept. Part 1: Investigation of Error Estimation of Neutron Spectra in FBR and Suggestions to Improve the Accuracy. In order to improve the spectrum unfolding method used in fast experimental reactor JOYO, a trial was made to evaluate the error in the estimated neutron spectrum, cause by cause. And the evaluated errors were summed up to obtain the most probable and reasonable error as possible. The summed up error was found relatively small compared to the error caused by the uncertainty of cross section data: most of the error in the spectrum unfolding method can be attributed to the error in cross sections. It was also found that the error due to the fission spectrum causes a considerable error in the high energy neutron spectrum which is over several MeV. Part 2: Study on Reactor Physics Analysis Method for Gas-Cooled FBR. In gas-cooled FBR, the portion of coolant channels in core volume is larger than sodium-cooled FBR. This leads to strong neutron streaming effects. For sodium-cooled FBR, several methods were proposed to evaluate the neutron streaming effect, however, these methods can not be used directly to gas-cooled reactor because the direction dependent diffusion coefficient becomes infinitive along the direction pararel to the coolant chammel. In this study, a new method is proposed to evaluate the neutron streaming effect, based on the method taking the axial buckling into consideration, which method was originally proposed by Khler. Part 3: Study on Reactor Physics Analysis Method for Water-Cooled FBR An investigation was made on low-moderated water-cooled FBR, on the point that the ordinary used analysis method for FBR may give considerable difference in results in such core. In light water reactors, it is well known that the space dependence of self-shielding effect of heavy nuclides are considerably ...
JNC TJ8400 2000-017, 74 Pages, 2000/02
The report concerns the improvement of the method measuring thermal conductivity of buffer materials using a thermistor probe and the measurement of thermal conductivity of compacted bentonites and mixtures of bentonite and silica sand using the proposed method measuring thermophysical properties. The method measuring thermal conductivity is improved in accuracy and the apparatus is improved so as to measure easily with more short time. The calculated values of the conventional correlations predicting thermal conductivity of bentonite and mixture were compared with the exising and present data of thermal conductivity of bentonites and mixtures. The correlation proposed by Sakashita and Kumada can predict the best fitted values with the data of the bentonites and Fricke and Bruggeman correlations are fitted with the data for the mixtures with practical accuracy.
Oigawa, Hiroyuki; Iijima, Susumu;
Journal of Nuclear Science and Technology, 36(10), p.902 - 913, 1999/10
Times Cited Count:2 Percentile:21.18(Nuclear Science & Technology)no abstracts in English
Oigawa, Hiroyuki; Iijima, Susumu; Ando, Masaki
Journal of Nuclear Science and Technology, 35(4), p.264 - 277, 1998/04
Times Cited Count:8 Percentile:56.62(Nuclear Science & Technology)no abstracts in English
JAERI-M 6677, 97 Pages, 1976/08
no abstracts in English
Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio
no journal, ,
Quality Assurance is an issue for computational science and engineering. It is well discussed in verification and validation for Simulation. In finite element analysis, it is a problem whether the finite element discretization is appropriate or not. Also, algorithmic choice prepared variously by the recent R&D discipline that become the problem which one to take. An experiment was performed for the static analysis and natural frequency analysis to confirm how uncertainty is revealed. As a result, by means to compare accuracy of the calculation precision that utilized a parallel environment, the numerical experiment reconfirmed that the estimate of the calculation solution was possible.