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Matsumoto, Toshinori; Hibiki, Takashi*; Maruyama, Yu
International Journal of Energy Research, 2024(1), p.9748588_1 - 9748588_18, 2024/08
Times Cited Count：1 Percentile：27.40(Energy & Fuels)To evaluate the effectiveness of the wet cavity strategy, the authors developed a stochastic evaluation method that considers the uncertainties of the molten material conditions ejected from reactor pressure vessels. The first step was uncertainty analysis using the MELCOR code to obtain the melt condition. Five uncertain parameters related to the core degradation process were chosen. The input parameter sets were generated using Latin hypercube sampling. The second step was analyzing of the melt-behavior using the JASMINE code. The probabilistic distribution of parameters for the JASMINE analyses was determined from the MELCOR analysis results. The initial water depth was set to 0.5, 1.0, and 2.0 m. The debris height was compared with the criterion to judge its coolability. Consequently, the success probability of debris cooling was obtained through a sequence of calculations. The feasibility and technical difficulties in the MELCOR-JASMINE combined analysis were also discussed.
Matsumoto, Toshinori; Kawabe, Ryuhei*; Iwasawa, Yuzuru; Sugiyama, Tomoyuki; Maruyama, Yu
Annals of Nuclear Energy, 178, p.109348_1 - 109348_13, 2022/12
Times Cited Count：3 Percentile：33.51(Nuclear Science & Technology)The Japan Atomic Energy Agency extended the applicability of their fuel-coolant interaction analysis code JASMINE to simulate the relevant phenomena of molten core in a severe accident. In order to evaluate the total coolability, it is necessary to know the mass fraction of particle, agglomerated and cake debris and the final geometry at the cavity bottom. An agglomeration model that considers the fusion of hot particles on the cavity floor was implemented in the JASMINE code. Another improvement is introduction of the melt spreading model based on the shallow water equation with consideration of crust formation at the melt surface. For optimization of adjusting parameters, we referred data from the agglomeration experiment DEFOR-A and the under-water spreading experiment PULiMS conducted by KTH in Sweden. The JASMINE analyses reproduced the most of the experimental results well with the common parameter set, suggesting that the primary phenomena are appropriately modelled.
Sahboun, N. F.; Matsumoto, Toshinori; Iwasawa, Yuzuru; Sugiyama, Tomoyuki
Proceedings of Asian Symposium on Risk Assessment and Management 2021 (ASRAM 2021) (Internet), 15 Pages, 2021/10
Li, C.-Y.; Uchibori, Akihiro; Takata, Takashi; Pellegrini, M.*; Erkan, N.*; Okamoto, Koji*
Dai-25-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 4 Pages, 2021/07
The capability of stable cooling and avoiding re-criticality on the debris bed are the main issues for achieving IVR (In-Vessel Retention). In the actual situation, the debris bed is composed of mixed-density debris particles. Hence, when these mixed-density debris particles were launched to re-distribute, the debris bed would possibly form a density-stratified distribution. For the proper evaluation of this scenario, the multi-physics model of CFD-DEM-Monte-Carlo based neutronics is established to investigate the coolability and re-criticality on the heterogeneous density-stratified debris bed with considering the particle relocation. The CFD-DEM model has been verified by utilizing water injection experiments on the mixed-density particle bed in the first portion of this research. In the second portion, the coupled system of the CFD-DEM-Monte-Carlo based neutronics model is applied to reactor cases. Afterward, the debris particles' movement, debris particles' and coolant's temperature, and the k-eff eigenvalue are successfully tracked. Ultimately, the relocation and stratification effects on debris bed's coolability and re-criticality had been quantitatively confirmed.
Uesawa, Shinichiro; Shibata, Mitsuhiko; Yamashita, Susumu; Yoshida, Hiroyuki
Proceedings of 10th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-10) (USB Flash Drive), 7 Pages, 2016/11
Maruyama, Yu*; Moriyama, Kiyofumi; Nakamura, Hideo; Hirano, Masashi; Nakajima, K.*
Journal of Nuclear Science and Technology, 40(1), p.12 - 21, 2003/01
Times Cited Count：6 Percentile：40.54(Nuclear Science & Technology)no abstracts in English
Kunitomi, Kazuhiko; Katanishi, Shoji; Takada, Shoji; Takizuka, Takakazu; Yan, X.; Nakata, Tetsuo; Takei, Masanobu; Kosugiyama, Shinichi; Shiozawa, Shusaku
Nihon Kikai Gakkai Dai-8-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.181 - 184, 2002/00
no abstracts in English
Maruyama, Yu; Moriyama, Kiyofumi; Nakamura, Hideo; Hashimoto, Kazuichiro; Hirano, Masashi; Nakajima, K.*
Proceedings of RASPLAV Seminar 2000 (CD-ROM), 8 Pages, 2000/11
no abstracts in English
Maruyama, Yu; ; Moriyama, Kiyofumi; H.S.Park*; Kudo, Tamotsu; Y.Yang*; Sugimoto, Jun
Nucl. Eng. Des., 187(2), p.241 - 254, 1999/00
Times Cited Count：20 Percentile：78.97(Nuclear Science & Technology)no abstracts in English
; Maruyama, Yu; Kudo, Tamotsu; Moriyama, Kiyofumi; Ito, Hideo; ; ; Sugimoto, Jun
JAERI-Tech 98-019, 105 Pages, 1998/06
no abstracts in English
21, 1997, Tokai-mura, Japan; ; Sugimoto, Jun
JAERI-Conf 97-011, 829 Pages, 1998/01
no abstracts in English
Maruyama, Yu; ; Moriyama, Kiyofumi; H.S.Park*; Kudo, Tamotsu; Y.Yang*; Sugimoto, Jun
JAERI-Conf 98-009, p.100 - 106, 1998/00
no abstracts in English
Kaminaga, Masanori; Yamamoto, Kazuyoshi
JAERI-Tech 97-016, 120 Pages, 1997/03
no abstracts in English
Maruyama, Yu; Yamano, Norihiro; Kudo, Tamotsu; Moriyama, Kiyofumi; Sugimoto, Jun
JAERI-memo 08-127, p.269 - 275, 1996/06
no abstracts in English
Maruyama, Yu; Yamano, N.; Moriyama, Kiyofumi; H.S.Park*; Kudo, Tamotsu; Sugimoto, Jun
NUREG/CP-0157, 2, p.161 - 172, 1996/00
no abstracts in English
Maruyama, Yu; Yamano, N.; Moriyama, Kiyofumi; H.S.Park*; Kudo, Tamotsu; Sugimoto, Jun
Proc. of Int. Topical Meeting on Probabilistic Safety Assessment (PSA96), 3, p.1367 - 1374, 1996/00
no abstracts in English
Maruyama, Yu; Yamano, N.; Kudo, Tamotsu; Hidaka, Akihide; Sugimoto, Jun
NEA/CSNI/R(95)3, 0, p.223 - 240, 1995/07
no abstracts in English
Sugimoto, Jun
Dennetsu Kenkyu, 34(133), p.52 - 59, 1995/04
no abstracts in English
Yamano, Norihiro; Maruyama, Yu; Kudo, Tamotsu; Hidaka, Akihide; Sugimoto, Jun
Nuclear Engineering and Design, 155(1-2), p.369 - 389, 1995/04
Times Cited Count：48 Percentile：96.12(Nuclear Science & Technology)no abstracts in English
Maruyama, Yu; Yamano, N.; Kudo, Tamotsu; Moriyama, Kiyofumi; Sugimoto, Jun
Proc., Seminar on the Vapor Explosions in Nuclear Power Safety,Kanzanji 1995, 0, p.54 - 69, 1995/00
no abstracts in English
