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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：0 Percentile：0.00(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.
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：40.84(Nuclear Science & Technology)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：79.15(Nuclear Science & Technology)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
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
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
Sato, Ikken
no journal, ,
It is necessary to maximize the knowledge with: (1) In-depth data analysis of 1F plant data, (2) Well-targeted experiments addressing the BWR-specific uncertainties, and (3) Evaluation of accident progression behavior based on integration of all the available information. In-depth analysis of Unit 2 and Unit 3 plant data was conducted as step (1). This step provided outlines of accident progression behavior in these units. This information is then reflected into SA code analyses. A series of plasma heating experiments using a test section simulating a part of BWR core were conducted to get insights for the above step (2). Core material relocation behavior in the high-temperature range up to ceramic fuel melting was observed in these tests. The above step (3) consisted of an evaluation of core thermal energy for Unit 2 and Unit 3.
