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Maruyama, Shuhei
Proceedings of International Conference on Physics of Reactors 2022 (PHYSOR 2022) (Internet), 10 Pages, 2022/05
This paper proposes a new homogenization method, "Boundary Condition Free Homogenization (BCFH)". The traditional homogenization method separates the core calculation and the cell (assembly) calculation by assuming a specific boundary condition or a peripheral region in the cell calculation. Nevertheless, there are ambiguities and approximation in these assumptions, and they can also cause a decline in accuracy. BCFH aims to avoid these problems and improve the accuracy in the cell calculation such as homogenization. We imposed the conditions that the physical quantities in the cell related to the reaction rate preservation is preserved for any incoming partial current, during the homogenization. That is, the response matrices of cell average (or total) flux and outgoing partial current, to be the same form between heterogeneous and homogeneous system. As a result, homogenized parameters, such as cross-sections, superhomgenization factors, and discontinuity factors, are no longer dependent on a specific boundary condition. The new homogenized parameters obtained in this way are extended from the conventional vector form to the matrix form in BCFH. To investigate the performance of BCFH, numerical tests are done for the simplified models which originates in 750MW-class sodium-cooled fast reactor with MOX fuel core in Japan. It is found that BCFH is particularly effective in evaluating control rod reactivity worth and reaction rate distribution, compared to the traditional method. We conclude that the BCFH can be a promising homogenization concept for core neutronic analysis.
Utsumi, Takayuki*; Yabe, Takashi*; Koga, J. K.; Aoki, Takayuki*; Sekine, Masatoshi*
Computer Physics Communications, 157(2), p.121 - 138, 2004/02
Times Cited Count:13 Percentile:51.42(Computer Science, Interdisciplinary Applications)no abstracts in English
Kuroishi, Takeshi; Nomura, Yasushi
Journal of Nuclear Science and Technology, 40(6), p.433 - 440, 2003/06
Times Cited Count:2 Percentile:18.89(Nuclear Science & Technology)Effective source acceleration method is studied in criticality safety analysis for realistic spent fuel transport cask. Various axial burnup profiles based on in-core flux measurements are proposed in the OECD/NEA/BUC benchmark Phase II-C. In some cases, calculations by ordinary Monte Carlo method show very slow convergence of fission source distribution, and unacceptably large skipped cycles are needed. The matrix eigenvector calculation that has been developed and incorporated in the ordinary Monte Carlo calculation to improve the slow convergence is applied to the benchmark. The efficiency of this method depends on the precision of matrix elements. In a certain stage of insufficient convergence of fission source distribution, especially for this benchmark of very slow convergence, more acceleration procedure causes anomalous results because of large statistical fluctuations of matrix elements corresponding to low source levels. Therefore, we propose effective source acceleration method with less calculation time than increasing histories for the estimation of matrix elements.
C.Degueldre*; Takano, Masahide; Omichi, Toshihiko; Fukuda, Kosaku; P.Heimgartner*; T.Graber*
JAERI-Research 97-087, 19 Pages, 1997/11
no abstracts in English
Journal of Nuclear Science and Technology, 23(4), P. 378, 1986/00
Times Cited Count:1 Percentile:55.96(Nuclear Science & Technology)no abstracts in English
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Progress of Theoretical Physics, 75(1), p.46 - 58, 1986/00
Times Cited Count:11 Percentile:63.56(Physics, Multidisciplinary)no abstracts in English
Journal of Nuclear Science and Technology, 22(5), p.398 - 405, 1985/00
Times Cited Count:6 Percentile:64.56(Nuclear Science & Technology)no abstracts in English
Journal of Nuclear Science and Technology, 21(4), p.299 - 307, 1984/00
Times Cited Count:5 Percentile:51.22(Nuclear Science & Technology)no abstracts in English
; ; ;
JAERI-M 82-080, 18 Pages, 1982/07
no abstracts in English
; Tsunematsu, Toshihide; ; ; ; Takeda, Tatsuoki
JAERI-M 9899, 56 Pages, 1982/01
no abstracts in English
; ; ;
Nuclear Fusion, 22(8), p.1031 - 1047, 1982/00
Times Cited Count:10 Percentile:41.00(Physics, Fluids & Plasmas)no abstracts in English
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JAERI-M 8253, 133 Pages, 1979/05
no abstracts in English
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JAERI-M 6952, 25 Pages, 1977/02
no abstracts in English
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Journal of Nuclear Science and Technology, 12(11), p.663 - 680, 1975/11
Times Cited Count:17no abstracts in English
; Izui, Kazuhiko
JAERI-M 5441, 66 Pages, 1973/11
no abstracts in English