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Okumura, Keisuke
Nihon Genshiryoku Gakkai Dai-36-Kai Robutsuri Kaki Semina Tekisuto, p.81 - 102, 2004/08
The modern node method which uses a discontinuous factor has come to be widely used recently in the reactor core analyses of commercial light water reactors. The basic theory, numerical computation technique and examples of calculation results are explained for biginners of the modern nodal method.
Takamatsu, Kuniyoshi; Shimakawa, Satoshi; Nojiri, Naoki; Fujimoto, Nozomu
JAERI-Tech 2003-081, 49 Pages, 2003/10
In the case of evaluations for the highest temperature of the fuels in the HTTR, it is very important to expect the power density distributions accurately; therefore, it is necessary to improve the analytical model with the neutron diffusion and the burn-up theory. The power density distributions are analyzed in terms of two models, the one mixing the fuels and the burnable poisons homogeneously and the other modeling them heterogeneously. Moreover these analytical power density distributions are compared wtih the ones derived from the gross -ray measurements and the Monte Carlo calculational code with continuous energy. As a result the homogeneous mixed model isn't enough to expect the power density distributions of the core in the axial direction; on the other hand, the heterogeneous model improves the accuracy.
Fujimura, Toichiro*; Okumura, Keisuke
JAERI-Research 2002-024, 27 Pages, 2002/11
A prototype version of a diffusion code has been developed to analyze the hexagonal core as reduced moderation reactor and the applicability of some acceleration methods have been investigated to accelerate the convergence of the iterative solution method. The hexagonal core is divided into regular triangular prisms in the three-dimensional code MOSRA-Prism and a polynomial expansion nodal method is applied to approximate the neutron flux distribution by a cubic polynomial. The multi-group diffusion equation is solved iteratively with ordinal inner and outer iterations and the effectiveness of acceleration methods is ascertained by applying an adaptive acceleration method and a neutron source extrapolation method, respectively. The formulation of the polynomial expansion nodal method is outlined in the report and the local and global effectiveness of the acceleration methods is discussed with various sample calculations. A new general expression of vacuum boundary condition, derived in the formulation is also described.
Okumura, Keisuke
JAERI-Data/Code 98-025, 243 Pages, 1998/10
no abstracts in English
JAERI-M 85-059, 69 Pages, 1985/05
no abstracts in English
Journal of Nuclear Science and Technology, 22(7), p.565 - 583, 1985/00
Times Cited Count:37 Percentile:95.21(Nuclear Science & Technology)no abstracts in English
Harada, Hiro;
Nihon Genshiryoku Gakkai-Shi, 27(11), p.1047 - 1055, 1985/00
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)no abstracts in English
;
Journal of Nuclear Science and Technology, 20(11), p.951 - 960, 1983/00
Times Cited Count:2 Percentile:34.94(Nuclear Science & Technology)no abstracts in English
;
Nuclear Science and Engineering, 77, p.360 - 367, 1981/00
Times Cited Count:2 Percentile:44.84(Nuclear Science & Technology)no abstracts in English
JAERI-M 8238, 29 Pages, 1979/05
no abstracts in English
Journal of Nuclear Science and Technology, 10(10), p.619 - 625, 1973/10
no abstracts in English
Mizoo, Nobutatsu*
Journal of Nuclear Science and Technology, 5(1), p.36 - 36, 1968/00
Times Cited Count:0no abstracts in English