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Lam, T.-N.*; Chin, H.-H.*; Zhang, X.*; Feng, R.*; Wang, H.*; Chiang, C.-Y.*; Lee, S. Y.*; Kawasaki, Takuro; Harjo, S.; Liaw, P. K.*; et al.
Acta Materialia, 245, p.118585_1 - 118585_9, 2023/02
Times Cited Count：8 Percentile：80.32(Materials Science, Multidisciplinary)Uchibori, Akihiro; Yanagisawa, Hideki*; Takata, Takashi; Li, J.*; Jang, S.*
Mechanical Engineering Journal (Internet), 7(3), p.19-00548_1 - 19-00548_11, 2020/06
Evaluation of occurrence possibility of tube failure propagation under sodium-water reaction accident is an important issue. In this study, a numerical analysis method to predict occurrence of failure propagation by overheating rupture was constructed to expand application range of an existing computer code. Applicability of the method was constructed through the numerical analysis of the experiment on water vapor discharging in liquid sodium. To improve the evaluation accuracy for the temperature distribution, a Lagrangian particle model for simulating reacting jet was also developed as an alternative method and its basic function was confirmed.
Uchibori, Akihiro; Yanagisawa, Hideki*; Takata, Takashi; Ohshima, Hiroyuki
Proceedings of 11th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-11) (Internet), 6 Pages, 2018/11
Evaluation of occurrence possibility of tube failure propagation under sodium-water reaction accident is an important issue. In this study, a numerical analysis method to predict occurrence of failure propagation by overheating rupture was constructed to expand application range of an existing computer code. Applicability of the method was constructed through the numerical analysis of the experiment on water vapor discharging in liquid sodium.
Uchibori, Akihiro; Takata, Takashi; Yanagisawa, Hideki*; Li, J.*; Jang, S.*
Proceedings of 2018 ANS Winter Meeting and Nuclear Technology Expo; Embedded Topical International Topical Meeting on Advances in Thermal Hydraulics (ATH 2018) (USB Flash Drive), p.1289 - 1294, 2018/11
Evaluation of occurrence possibility of tube failure propagation under sodium-water reaction accident is an important issue. In this study, a numerical analysis method to predict occurrence of failure propagation by overheating rupture was constructed to expand application range of an existing computer code. Applicability of the method was constructed through the numerical analysis of the experiment on water vapor discharging in liquid sodium. To improve the evaluation accuracy for the temperature distribution, a Lagrangian particle model for simulating reacting jet was also developed as an alternative method and its basic function was confirmed.
Matsumoto, Toshinori; Sato, Masatoshi; Sugiyama, Tomoyuki; Maruyama, Yu
Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 6 Pages, 2017/07
Uchibori, Akihiro; Ohshima, Hiroyuki
Mechanical Engineering Journal (Internet), 3(3), p.15-00620_1 - 15-00620_9, 2016/06
For assessment of the wastage environment under tube failure accident, a mechanistic computer code called SERAPHIM calculating compressible multicomponent multiphase flow with sodium-water chemical reaction has been developed. In this study, applicability of the SERAPHIM code was investigated through the analysis of the experiment on water vapor discharging in liquid sodium under actual condition of the steam generator. The numerical result showed that the underexpanded jet appeared and impinged on the target tube located above the discharging tube. The calculated temperature distribution agreed with the measurement result well. The liquid droplet entrainment and its transport were considered in this analysis. The region with higher impingement velocity of the liquid droplet was close to the wastage region confirmed in the experiment. It was demonstrated that the SERAPHIM code could predict the temperature distribution and the environment of LDIE under the actual condition.
Uchibori, Akihiro; Ohshima, Hiroyuki
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 7 Pages, 2015/05
For assessment of the wastage environment under tube failure accident, a mechanistic computer code called SERAPHIM calculating compressible multicomponent multiphase flow with sodium-water chemical reaction has been developed. In this study, applicability of the SERAPHIM code was investigated through the analysis of the experiment on water vapor discharging in liquid sodium under actual condition of the steam generator. The numerical result showed that the underexpanded jet appeared and impinged on the target tube located above the discharging tube. The calculated temperature distribution agreed with the measurement result well. The liquid droplet entrainment and its transport were considered in this analysis. The region with higher impingement velocity of the liquid droplet was close to the wastage region confirmed in the experiment. It was demonstrated that the SERAPHIM code could predict the temperature distribution and the environment of LDIE under the actual condition.
Miyazaki, Akemi
Kozo Kogaku Rombunshu, B, 52B, p.119 - 124, 2006/03
Since it is generally difficult to predict the occurrence of natural disasters such as earthquakes, a performance management system that always maintains the safety and functionalities of structures is required, especially for critical ones like nuclear power plants. In order to realize such a system, it is becoming important to carry out modeling procedures and analyses in detail to better understand the real phenomena. Such details are important in understanding the phenomena occurring in frame structures such as piping systems which are considered to be one of the vulnerable parts in nuclear power plants. The aim of our research is to solve the dynamic behavior of piping systems in nuclear power plants which are complicated assemblages of parts. The spectral element method is adopted in this work and the formulation considering a shear deformation of a frame element is described. The Timoshenko beam theory is introduced for the purpose of this formulation. The validity of the presented element will be shown through comparisons made with the conventional beam.
Al cable-in-conduit conductorKoizumi, Norikiyo; Matsui, Kunihiro; Kume, Etsuo; Okuno, Kiyoshi
IEEE Transactions on Applied Superconductivity, 15(2), p.1363 - 1366, 2005/06
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)The NbAl Insert was developed by JAERI aiming at the demonstration of a NbAl conductor to fusion reactor magnets. A quench test was performed on the NbAl Insert at 13 T with various temperature margins, which are defined as a difference between current sharing temperature and operating temperature. The initial normalcy was initiated by using an inductive heater and a coil current was kept for several seconds. The normal zone propagation velocity was accelerated after 3 s from the onset of heating in case that the temperature margin was set at 0.5 K. A simulation using one-dimensional stability and quench simulation code was performed. The calculation results indicate that such rapid propagation occurred due to a temperature rise beyond a current sharing temperature because of a large pressure increase even at the location where the normal front did not reach yet. This large pressure rise was caused since the coolant was contained in the closed circulation circuit of the cooling system, which is usually applied to a large magnet cooling system.
Homma, Toshimitsu; Tomita, Kenichi*; Hato, Shinji*
Nuclear Engineering and Technology, 37(3), p.245 - 258, 2005/06
This paper addresses two types of uncertainty: stochastic uncertainty and subjective uncertainty in probabilistic accident consequence assessments. The off-site consequence assessment code OSCAAR has been applied to uncertainty and sensitivity analyses on the individual risks of early fatality and latent cancer fatality in the population due to a severe accident. A new stratified meteorological sampling scheme was successfully implemented into the trajectory model for atmospheric dispersion and the statistical variability of the probability distributions of the consequence was examined. A total of 65 uncertain input parameters was considered and 128 runs of OSCAAR were performed in the parameter uncertainty analysis. The study provided the range of uncertainty for the expected values of individual risks of early and latent cancer fatality close to the site. In the sensitivity analyses, the correlation/regression measures were useful for identifying those input parameters whose uncertainty makes an important contribution to the overall uncertainty for the consequence.
Miyazaki, Akemi
Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 6 Pages, 2005/05
Since it is generally difficult to predict the occurrence of the natural disasters such as earthquakes, a performance management system that always maintains the safety of the structures is required, especially for the critical ones like the nuclear power plants. To realize such a system, it is becoming important to carry out modeling procedures and analyses in detail to capture the real phenomena. Such details are important in understanding the phenomena occurring in the frame structures such as piping systems which are considered to be one of the most weakest and vulnerable parts in the nuclear power plants. The aim of our research is to solve the dynamic behavior, especially the wave propagation phenomena for the piping systems in the nuclear power. The spectral element method is adopted in this work and the formulation considering a shear deformation of a frame element is described. Timoshenko beam theory is introduced for the purpose of this formulation. The validity of the presented element will be shown through the comparisons made with the conventional beam element.
Moriyama, Kiyofumi; Nakamura, Hideo; Maruyama, Yu
Proceedings of 6th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operations and Safety (NUTHOS-6) (CD-ROM), 18 Pages, 2004/10
A steam explosion simulation code JASMINE is under development at JAERI for the assessment of steam explosion impacts on the integrity of containment vessel during severe accidents in light water reactors. Selected alumina and corium steam explosion experiments, KROTOS-44, 42, 37 and FARO-L33 were simulated with JASMINE code. The experimentally observed difference of the steam explosion intensity with the two materials, alumina and corium, was reproduced in the simulations without changing the model parameters related to the fine fragmentation process, but based on the difference in the premixing behavior predicted by the simulations. The simulation of corium experiments showed more fraction of the melt droplets frozen during premixing, as well as more void fraction, and those two points were likely to be the primary reasons of weak interactions in corium experiments.
Shibata, Taiju; Ishihara, Masahiro
Proceedings of International Conference on Advanced Technology in Experimental Mechanics 2003 (ATEM '03) (CD-ROM), 5 Pages, 2003/09
no abstracts in English
Shibata, Taiju; Ishihara, Masahiro
Transactions of 17th International Conference on Structural Mechanics in Reactor Technology (SMiRT-17) (CD-ROM), 8 Pages, 2003/08
no abstracts in English
Shibata, Taiju; Ishihara, Masahiro
Transactions of 16th International Conference on Structural Mechanics in Reactor Technology (SMiRT-16) (CD-ROM), 8 Pages, 2001/08
no abstracts in English
Isono, Takaaki; Matsui, Kunihiro; Kato, Takashi; Takahashi, Yoshikazu; CS Model Coil Test Group; Hasegawa, Mitsuru*
Teion Kogaku, 36(6), p.373 - 380, 2001/06
no abstracts in English
Yang, Y.; Nilsuwankosit, S.; Moriyama, Kiyofumi; Maruyama, Yu; Nakamura, Hideo; Hashimoto, Kazuichiro
JAERI-Data/Code 2000-035, 86 Pages, 2000/12
JAERI-Data-Code-2000-035.pdf:4.01MB
no abstracts in English
Yamagishi, Hideshi; Ikeda, Yujiro; Ito, Hiroshi; Kakuta, Tsunemi; Nakakawa, Masayuki; Iwamura, Takamichi; Tabata, Hiroaki*; Urakami, Masao*
JAERI-Tech 2000-037, p.12 - 0, 2000/03
JAERI-Tech-2000-037.pdf:1.12MB
no abstracts in English
Utsumi, Takayuki*; Sasaki, Akira
Dai-14-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu, 4 Pages, 2000/00
no abstracts in English
Ishihara, Masahiro; Shibata, Taiju
Dai-4-Kai Kozobutsu No Anzensei, Shinraisei Ni Kansuru Kokunai Shimpojiumu Koen Rombunshu, p.101 - 108, 2000/00
no abstracts in English
