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random mediaAraki, Shohei; Yamane, Yuichi; Ueki, Taro; Tonoike, Kotaro
Nuclear Science and Engineering, 195(10), p.1107 - 1117, 2021/10
Times Cited Count：2 Percentile：22.61(Nuclear Science & Technology)Criticality control of random media such as fuel debris is one of the most important safety issues in post-accident management. 
spectrum randomizing model is expected to simulate such random media because it is well known that the noise can describe a diverse range of random and disordered natural phenomena. In this paper, we focused on the relationship between the multiplication factor and moderation condition in the random media. A number of random media were realized with the spectrum randomizing model that is based on the Randomized Weierstrass function (RWF). The volume ratio of concrete to fuel was adopted as an index for the moderation condition. The multiplication factors were calculated with a two-energy group Monte Carlo calculation. The calculation results were analyzed by using variance, skewness, and kurtosis. Those statistical parameters had an extreme value around the optimum moderation condition. This result suggested that it is possible to predict the rough trend of variation range, distortion, and outlier of multiplication factors in the random media.
on effective multiplication factor in 1/f
spectrum random systemAraki, Shohei; Yamane, Yuichi; Ueki, Taro; Tonoike, Kotaro
Proceedings of International Conference on the Physics of Reactors; Transition To A Scalable Nuclear Future (PHYSOR 2020) (USB Flash Drive), 8 Pages, 2020/03
We investigated the dependence of the effective multiplication factor (k
) in the 1/f noise model. We conducted the two-group Monte Carlo calculations. We found that the standard deviation of the k distribution showed the positive correlation with the value because the spatial distribution of the fuel became less uniform as the value increased.
Nagaya, Yasunobu; Ueki, Taro; Tonoike, Kotaro
Proceedings of 11th International Conference on Nuclear Criticality Safety (ICNC 2019) (Internet), 9 Pages, 2019/09
A new Monte Carlo solver Solomon has been developed for the application to fuel-debris systems. It is designed not only for usual criticality safety analysis but also for criticality calculations of damaged reactor core including fuel debris. This paper describes the current status of Solomon and demonstrates the applications of the randomized Weierstrass function (RWF) model and the RWF model superimposed voxel geometry.
Sakurai, Kiyoshi; Ueki, Kotaro*
Nihon Genshiryoku Gakkai-Shi, 43(4), p.351 - 352, 2001/04
no abstracts in English
Sakurai, Kiyoshi; Ueki, Kotaro*; Naito, Yoshitaka*
Nihon Genshiryoku Gakkai-Shi, 43(3), p.219 - 220, 2001/03
no abstracts in English
Sakurai, Kiyoshi; Kume, Etsuo; Yatabe, Shigeru*; Maekawa, Fujio; Yamamoto, Toshihiro; Nagaya, Yasunobu; Mori, Takamasa; Ueki, Kotaro*; Naito, Yoshitaka*
JAERI-Review 2000-034, 133 Pages, 2001/02
JAERI-Review-2000-034.pdf:7.69MB
no abstracts in English
Sakurai, Kiyoshi; Kume, Etsuo; Yatabe, Shigeru*; Maekawa, Fujio; Yamamoto, Toshihiro; Nagaya, Yasunobu; Mori, Takamasa; Ueki, Kotaro*; Naito, Yoshitaka*
Nihon Genshiryoku Gakkai-Shi, 42(10), p.1062 - 1065, 2000/10
no abstracts in English
Sakurai, Kiyoshi; Ueki, Kotaro*; Naito, Yoshitaka*
Nihon Genshiryoku Gakkai-Shi, 42(10), p.1048 - 1049, 2000/10
no abstracts in English
Sakurai, Kiyoshi; Yamamoto, Toshihiro; Ueki, Kotaro*; Mori, Takamasa; Nomura, Yasushi; Naito, Yoshitaka*
Journal of Nuclear Science and Technology, 37(Suppl.1), p.446 - 448, 2000/03
no abstracts in English
Sakurai, Kiyoshi; Ueki, Kotaro*; Naito, Yoshitaka*
Nihon Genshiryoku Gakkai-Shi, 42(2), p.114 - 115, 2000/02
no abstracts in English
Ueki, Kotaro*; Mori, Takamasa; Sakurai, Kiyoshi; Nakagawa, Masayuki;
Nihon Genshiryoku Gakkai-Shi, 41(6), p.614 - 627, 1999/00
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
Oyama, Yukio; ; Watanabe, Yukinobu*; Kawano, Toshihiko*; Numajiri, M.*; Ueki, Kotaro*; ; Yamano, Naoki*; Kosako, Kazuaki*; ; et al.
JAERI-Review 98-020, 130 Pages, 1998/11
no abstracts in English
Nakane, Yoshihiro; Nakashima, Hiroshi; Nakao, Noriaki*; Ueki, Kotaro*
Proc. of 3rd Workshop on Simulating Accelerator Radiation Environments (SARE3), p.334 - 342, 1997/00
no abstracts in English
frequency spectrumAraki, Shohei; Yamane, Yuichi; Ueki, Taro; Tonoike, Kotaro
no journal, ,
We investigated the effect of the degree of randomness on the distribution of neutron multiplication factors (
) calculated for fuel debris for the purpose of criticality risk assessment. The calculation results with the model randomized with frequency spectrum showed a positive correlation between the exponent and variance of the () distribution.
