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Sueoka, Shigeru; Kawakami, Tetsuo*; Suzuki, Kota*; Kagami, Saya; Yokoyama, Tatsunori; Shibazaki, Bunichiro*; Nagata, Mitsuhiro; Yamazaki, Ayu*; Higashino, Fumiko*; King, G. E.*; et al.
Fisshion, Torakku Nyusureta, (36), p.1 - 3, 2023/12
no abstracts in English
Hayakawa, Sho*; Yamamoto, Yojiro*; Okita, Taira*; Itakura, Mitsuhiro; Suzuki, Katsuyuki*
Computational Materials Science, 218, p.111987_1 - 111987_10, 2023/02
Times Cited Count:1 Percentile:14.66(Materials Science, Multidisciplinary)Tsugawa, Kiyoto*; Hayakawa, Sho*; Okita, Taira*; Aichi, Masaatsu*; Itakura, Mitsuhiro; Suzuki, Katsuyuki*
Computational Materials Science, 215, p.111806_1 - 111806_8, 2022/12
Times Cited Count:2 Percentile:29.01(Materials Science, Multidisciplinary)Tsugawa, Kiyoto*; Hayakawa, Sho*; Iwase, Yuki*; Okita, Taira*; Suzuki, Katsuyuki*; Itakura, Mitsuhiro; Aichi, Masaatsu*
Computational Materials Science, 210, p.111450_1 - 111450_9, 2022/07
Times Cited Count:8 Percentile:75.5(Materials Science, Multidisciplinary)Mori, Sho*; Matsuda, Nayuta*; Okita, Taira*; Aichi, Masaatsu*; Itakura, Mitsuhiro; Suzuki, Katsuyuki*
Materialia, 21, p.101371_1 - 101371_6, 2022/03
Okita, Taira*; Terayama, Satoshi*; Tsugawa, Kiyoto*; Kobayashi, Keita; Okumura, Masahiko; Itakura, Mitsuhiro; Suzuki, Katsuyuki*
Computational Materials Science, 202, p.110865_1 - 110865_9, 2022/02
Times Cited Count:7 Percentile:48.44(Materials Science, Multidisciplinary)Terayama, Satoshi*; Iwase, Yuki*; Hayakawa, Sho*; Okita, Taira*; Itakura, Mitsuhiro; Suzuki, Katsuyuki*
Computational Materials Science, 195, p.110479_1 - 110479_12, 2021/07
Times Cited Count:9 Percentile:57.69(Materials Science, Multidisciplinary)Kuroda, Kenta*; Arai, Yosuke*; Rezaei, N.*; Kunisada, So*; Sakuragi, Shunsuke*; Alaei, M.*; Kinoshita, Yuto*; Bareille, C.*; Noguchi, Ryo*; Nakayama, Mitsuhiro*; et al.
Nature Communications (Internet), 11, p.2888_1 - 2888_9, 2020/06
Times Cited Count:20 Percentile:75.49(Multidisciplinary Sciences)Hayakawa, Sho*; Doihara, Kohei*; Okita, Taira*; Itakura, Mitsuhiro; Aichi, Masaatsu*; Suzuki, Katsuyuki*
Journal of Materials Science, 54(17), p.11509 - 11525, 2019/09
Times Cited Count:15 Percentile:56.33(Materials Science, Multidisciplinary)Hayakawa, Sho*; Okita, Taira*; Itakura, Mitsuhiro; Kawabata, Tomoya*; Suzuki, Katsuyuki*
Journal of Materials Science, 54(16), p.11096 - 11110, 2019/08
Times Cited Count:11 Percentile:42.21(Materials Science, Multidisciplinary)Nakanishi, Daiki*; Kawabata, Tomoya*; Doihara, Kohei*; Okita, Taira*; Itakura, Mitsuhiro; Suzuki, Katsuyuki*
Philosophical Magazine, 98(33), p.3034 - 3047, 2018/09
Times Cited Count:10 Percentile:47.84(Materials Science, Multidisciplinary)By using the six sets of interatomic potentials for face-centredcubic metals that differ in the stacking fault energy (SFE) while most of the other material parameters are kept almost identical, we conducted molecular dynamics simulations to evaluate the effects of SFE on the defect formation process through collision cascades. The ratio of glissile SIA clusters tends to decrease with increasing SFE. This is because perfect loops, the edges of which split into two partial dislocations with stacking fault structures between them in most cases, prefer to form at lower SFEs. The enhanced formation of glissile SIA clusters at lower SFEs can also be observed even at increased temperature.
Hayakawa, Sho*; Okita, Taira*; Itakura, Mitsuhiro; Aichi, Masaatsu*; Suzuki, Katsuyuki*
Philosophical Magazine, 98(25), p.2311 - 2325, 2018/06
Times Cited Count:8 Percentile:40.77(Materials Science, Multidisciplinary)We conduct kinetic Monte Carlo simulations for the conservative climb motion of a cluster of self-interstitial atoms towards another SIA cluster in BCC Fe; the conservative climb velocity is inversely proportional to the fourth power of the distance between them, as per the prediction based on Einstein's equation. The size of the climbing cluster significantly affects its conservative climb velocity, while the size of the cluster that originates the stress field does not. The activation energy for the conservative climb is considerably greater than that derived in previous studies and strongly dependent on the climbing cluster size.
Doihara, Kohei*; Okita, Taira*; Itakura, Mitsuhiro; Aichi, Masaatsu*; Suzuki, Katsuyuki*
Philosophical Magazine, 98(22), p.2061 - 2076, 2018/05
Times Cited Count:20 Percentile:71.42(Materials Science, Multidisciplinary)In this study, molecular dynamics simulations were performed to elucidate the effects of stacking fault energy (SFE) on the physical interactions between an edge dislocation and a spherical void in the crystal structure of face-centred cubic metals at various temperatures and for different void sizes. Four different types of interaction morphologies were observed, in which (1) two partial dislocations detached from the void separately, and the maximum stress corresponded to the detachment of the trailing partial; (2) two partial dislocations detached from the void separately, and the maximum stress corresponded to the detachment of the leading partial; (3) the partial dislocations detached from the void almost simultaneously without jog formation; and (4) the partial dislocations detached from the void almost simultaneously with jog formation. With an increase in void size or SFE, the interaction morphology changed in the above-mentioned order. It was observed that the magnitude of the critical resolved shear stress (CRSS) and its dependence on the SFE were determined by these interaction morphologies. The value of the CRSS in the case of interaction morphology (1) is almost equal to an analytical one based on the linear elasticity by employing the Burgers vector of a single partial dislocation. The maximum value of the CRSS is also obtained by the analytical model with the Burgers vector of the two partial dislocations.
Kuroda, Kenta*; Ochi, Masayuki*; Suzuki, Hiroyuki*; Hirayama, Motoaki*; Nakayama, Mitsuhiro*; Noguchi, Ryo*; Bareille, C.*; Akebi, Shuntaro*; Kunisada, So*; Muro, Takayuki*; et al.
Physical Review Letters, 120(8), p.086402_1 - 086402_6, 2018/02
Times Cited Count:50 Percentile:91.96(Physics, Multidisciplinary)Ito, Daisuke*; Rivera, M. N.*; Saito, Yasushi*; Aoyagi, Mitsuhiro; Kamiyama, Kenji; Suzuki, Toru*
Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 10 Pages, 2017/09
Nava, M.*; Ito, Daisuke*; Saito, Yasushi*; Aoyagi, Mitsuhiro; Kamiyama, Kenji; Suzuki, Toru*
Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 5 Pages, 2017/07
Ito, Daisuke*; Nava, M.*; Saito, Yasushi*; Aoyagi, Mitsuhiro; Kamiyama, Kenji; Suzuki, Toru*
Proceedings of 2017 Japan-US Seminar on Two-Phase Flow Dynamics (JUS 2017), 4 Pages, 2017/06
Aoyagi, Mitsuhiro; Kamiyama, Kenji; Tobita, Yoshiharu; Suzuki, Toru
Proceedings of 10th International Topical Meeting on Nuclear Thermal Hydraulics, Operation and Safety (NUTHOS-10) (USB Flash Drive), 14 Pages, 2014/12
A numerical model for freezing and blockage formation of solid-liquid flow in the SIMMER code was validated in order to improve the accuracy in evaluating fuel discharge behavior in the core disruptive accident of FBR. The THEFIS experiment which investigated fuel discharge behavior was chosen as reference data in this study. The numerical conditions were set according to the experimental system. Although the experimental result was well simulated by using the existing numerical model of SIMMER, the melt flow was suppressed excessively in some cases. Overestimation of flow resistance by the solid particles in the numerical model was discovered though the comparison between the numerical model and the physical phenomenon in the experiment. The numerical model caused the excessive melt flow suppression. Therefore, we improved the numerical model to adapt to the actual phenomenon. Then, it was confirmed the improved numerical model brought more appropriate numerical results.
Suzuki, Mitsuhiro; Nakamura, Hideo
Journal of Nuclear Science and Technology, 47(12), p.1193 - 1205, 2010/12
Times Cited Count:2 Percentile:17.46(Nuclear Science & Technology)Presented in the paper are experimental results on general performance of core exit thermocouple (CET) to detect core overheat for accident management (AM) action. Thirteen tests simulating small break loss-of-coolant accident (SBLOCA) and abnormal transient are studied by using the Large Scale Test Facility (LSTF) which is a full-height, full-pressure and 1/48 volumetric-scaled PWR model. Clarified are as follows, (1) general CET performance with certain delay in time and temperature rise from core overheating in most cases, (2) one common reason of the delay due to cooling effects of metal structures in core and core exit, (3) an indication of superheat instead of its temperature necessary for significantly high or low pressure transients, (4) no CET heat-up in case of large water fall-back from hot legs and in addition, discussion on applicability to PWR is presented.
Suzuki, Mitsuhiro; Takeda, Takeshi; Nakamura, Hideo
JAEA-Research 2009-057, 188 Pages, 2010/02
A series of break size parameter tests (SB-PV-07 and SB-PV-08) were conducted at the Large Scale Test Facility of ROSA-V Program to have an insight into effects of accident management action on core cooling during a simulated vessel top break loss-of-coolant accident with a total failure assumption on the high pressure injection (HPI) system at a pressurized water reactor (PWR). Typical phenomena of vessel top break with break sizes between 1.0 and 0.1% cold leg break equivalent were clarified including upper head water level transients related to steam discharge, coolant mass inventory related to core heat-up, performance of core exit thermocouple (CET)and three-dimensional steam flows in core and core exit. Both operator actions of HPI recovery in the 1.0% top break and steam generator depressurization in the 0.1% top break resulted in immediate recovery of core cooling when these were initiated by CET heat-up at 623 K.