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Li, L.*; Miyamoto, Goro*; Zhang, Y.*; Li, M.*; Morooka, Satoshi; Oikawa, Katsunari*; Tomota, Yo*; Furuhara, Tadashi*
Journal of Materials Science & Technology, 184, p.221 - 234, 2024/06
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Kang, Z.; Okuda, Yukihiko; Nishida, Akemi; Tsubota, Haruji; Li, Y.
Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03
Most studies conducted till now on local damage of reinforced concrete (RC) slab structures subjected to projectile impact are about normal impact, while few research related to oblique impact can be found. The objective of this study is to carry out impact tests under different impact conditions including oblique impacts, to confirm the different impact behaviors of the RC slab structure, to develop an analysis method by investigating the test results and analytical conditions, and to validate the analysis method through comparison with the test results. This study focuses on the scabbing damage which is one of the local damage modes of RC slab. Based on oblique impact test results due to soft projectile with hemispherical nose shape, we investigate the relationship between the criterion related to the concrete fracture and the occurrence of scabbing damage.
Okuda, Yukihiko; Kang, Z.; Nishida, Akemi; Tsubota, Haruji; Li, Y.
Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03
The outer walls of nuclear facility buildings consist of reinforced concrete (RC) panels. When a projectile collides with a nuclear facility building, local damages such as penetration, scabbing, and perforation can occur in the RC panels. Numerical simulation using finite element analysis (FEA) is generally employed to assess these damage conditions. However, the impact analysis by FEA modelled with continuum elements is difficult to address phenomena such as scattering fragments of concrete because the elements deletion method for large deformation is used to prevent interruption of numerical calculations. Recently, a numerical method known as Smooth Particles Hydrodynamics (SPH), one of the particle methods, has been employed to address discontinuous phenomena. In this paper, we focus on the scabbing damages to RC panels and report on the findings obtained through the validation of the numerical analysis using the SPH method.
Yamaguchi, Yoshihito; Mano, Akihiro; Li, Y.
Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03
The steam generator (SG) is an important component of a pressurized water reactor. In addition, local wall-thinning has been reported in SG tubes. The burst differential pressure, considering both the internal and external pressures from the primary and secondary coolant systems, should be predicted for the failure probability evaluation or structural integrity assessment of SG tubes. In this study, based on the results of burst tests performed in Japan and the United States, we improved the existing burst pressure estimation method for SG tubes with wall-thinning. In addition, as an example of the utilization of the improved burst pressure estimation method, the conditional failure probabilities for SG tubes with local wall-thinning, which is necessary for probabilistic risk assessment and risk-informed decision making, are calculated considering the dimensions of the wall-thinning.
Huang, Z.*; Wang, W.*; Ye, H.*; Bao, S.*; Shangguan, Y.*; Liao, J.*; Cao, S.*; Kajimoto, Ryoichi; Ikeuchi, Kazuhiko*; Deng, G.*; et al.
Physical Review B, 109(1), p.014434_1 - 014434_9, 2024/01
Times Cited Count:0Rhm, W.*; Ban, Nobuhiko*; Chen, J.*; Li, C.*; Dobynde, M.*; Durante, M.*; El-Jaby, S.*; Komiyama, Tatsuto*; Ozasa, Kotaro*; Sato, Tatsuhiko; et al.
Journal of Medical Physics - Zeitschrift fr medizinische Physik -, 10 Pages, 2024/00
The International Commission on Radiological Protection (ICRP) provides independent recommendations on radiological protection for the public benefit. For more than 90 years, the ICRP System of Radiological Protection has been guiding the development and implementation of national and international standards and regulations on radiological protection. In 2019, ICRP established Task Group (TG) 115 to address a broader range of topics related to dose and risk assessment for radiological protection of astronauts. This paper gives an overview of the System of Radiological Protection and a brief summary of ICRP's work on radiological protection of astronauts.
Li, F.; Mihara, Takeshi; Udagawa, Yutaka
Journal of Nuclear Science and Technology, 11 Pages, 2024/00
Times Cited Count:0Zhou, L.*; Zhang, H.*; Qin, T. Y.*; Hu, F. F.*; Xu, P. G.; Ao, N.*; Su, Y. H.; He, L. H.*; Li, X. H.*; Zhang, J. R.*; et al.
Metallurgical and Materials Transactions A, 11 Pages, 2024/00
Times Cited Count:0Zhang, A.*; Deng, K.*; Sheng, J.*; Liu, P.*; Kumar, S.*; Shimada, Kenya*; Jiang, Z.*; Liu, Z.*; Shen, D.*; Li, J.*; et al.
Chinese Physics Letters, 40(12), p.126101_1 - 126101_8, 2023/12
Times Cited Count:1 Percentile:0(Physics, Multidisciplinary)Fujimori, Shinichi; Kawasaki, Ikuto; Takeda, Yukiharu; Yamagami, Hiroshi; Sasabe, Norimasa*; Sato, Yoshiki*; Shimizu, Yusei*; Nakamura, Ai*; Maruya, A.*; Homma, Yoshiya*; et al.
Electronic Structure (Internet), 5(4), p.045009_1 - 045009_7, 2023/11
Tamii, Atsushi*; Pellegri, L.*; Sderstrm, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.
European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09
Times Cited Count:1 Percentile:0.02(Physics, Nuclear)no abstracts in English
Bao, S.*; Gu, Z.-L.*; Shangguan, Y.*; Huang, Z.*; Liao, J.*; Zhao, X.*; Zhang, B.*; Dong, Z.-Y.*; Wang, W.*; Kajimoto, Ryoichi; et al.
Nature Communications (Internet), 14, p.6093_1 - 6093_9, 2023/09
Times Cited Count:1 Percentile:61.99(Multidisciplinary Sciences)Hasegawa, Kunio; Li, Y.; Udyawar, A.*; Lacroix, V.*
International Journal of Pressure Vessels and Piping, 204, p.104952_1 - 104952_7, 2023/08
Times Cited Count:0 Percentile:0(Engineering, Multidisciplinary)When axial cracks were detected in pipes, failure stresses for high toughness pipes are estimated using the Limit Load Criteria. The allowable stresses for the cracked pipes are derived from the combination of the failure stresses and safety factors. The allowable sizes of crack depths and lengths are determined from the allowable stresses. From the comparison of the allowable and failure stresses for through-wall cracks, the allowable cracks are not uniform. They can be separated into three different characteristics, i) leak-before-break (LBB) and crack growth stability, ii) non-LBB and crack growth stability and iii) non-LBB and crack growth instability. Inspectors and users should pay special attention to allowable cracks with the third characteristic to prevent unexpected failure, particularly for thin-wall pipes. The allowable crack depths and lengths that require special attention can be expressed by appropriate equations.
Choi, B.; Nishida, Akemi; Shiomi, Tadahiko; Kawata, Manabu; Li, Y.; Ota, Akira*; Sonobe, Hideaki*; Ino, Susumu*; Ugata, Takeshi*
Mechanical Engineering Journal (Internet), 10(4), p.23-00026_1 - 23-00026_11, 2023/08
In the seismic evaluation of nuclear facility buildings, basemat uplift-the phenomenon during which the bottom of the basemat of a building partially rises from the ground owing to overturning moments during earthquakes-is a very important aspect because it affects not only structural strength and integrity, but also the response of equipment installed in the building. However, there are not enough analytical studies on the behavior of buildings with a low ground contact ratio due to basemat uplift during earthquakes. In this study, we conducted a simulation using a three-dimensional finite element model from past experiments on basemat uplift; further, we confirmed the validity of this approach. In order to confirm the difference in the analytical results depending on the analysis code, the simulation was performed under the same analytical conditions using the three analysis codes, which are E-FrontISTR, FINAS/STAR and TDAPIII, and the obtained analysis results were compared. Accordingly, we investigated the influence of the difference in adhesion on the structural response at low ground contact ratio. In addition, we confirmed the effects of significant analysis parameters on the structural response via sensitivity analysis. In this paper, we report the analytical results and insights obtained from these investigations.
Lu, K.; Takamizawa, Hisashi; Li, Y.; Masaki, Koichi*; Takagoshi, Daiki*; Nagai, Masaki*; Nannichi, Takashi*; Murakami, Kenta*; Kanto, Yasuhiro*; Yashirodai, Kenji*; et al.
Mechanical Engineering Journal (Internet), 10(4), p.22-00484_1 - 22-00484_13, 2023/08
Kondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
Times Cited Count:5 Percentile:92.64(Multidisciplinary Sciences)no abstracts in English
Chen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Chazono, Yoshiki*; Hagen, G.*; Holt, J. D.*; et al.
Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08
Times Cited Count:1 Percentile:0.02(Astronomy & Astrophysics)Gamma decays were observed in Ca and Ca following quasi-free one-proton knockout reactions from Sc. For Ca, a ray transition was measured to be 1456(12) keV, while for Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the decays. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the and orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic Ca and potentially drives the dripline of Ca isotopes to Ca or even beyond.
Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
Times Cited Count:2 Percentile:68.16(Astronomy & Astrophysics)Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.
Ariyoshi, Gen; Saruta, Koichi; Kogawa, Hiroyuki; Futakawa, Masatoshi; Maeno, Koki*; Li, Y.*; Tsutsui, Kihei*
Proceedings of 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20) (Internet), p.1407 - 1420, 2023/08
Cavitation damage on a target vessel due to proton beam-induced pressure waves is one of the crucial issues for the pulsed neutron source using a mercury spallation target. As a mitigation technique for the damage, the helium microbubble injection into the mercury has been carried out by using a swirl bubbler in order to utilize compressibility of bubbles. Moreover, double-walled structure, which consists of an outer wall and an inner wall, has been applied as the target head structure. In this study, we aim to develop an abnormality diagnostic technology to detect the inner wall cracking, which is caused by such cavitation damage, from the outside of the target vessel. The mercury flow fields in the case with the cracking are evaluated by computational fluid dynamics analysis based on finite element method. And then, effect of the cracking on the flow field is discussed from the point of view of the flow-induced vibration and the acoustic vibration.
Wang, Y.*; Gong, W.; Kawasaki, Takuro; Harjo, S.; Zhang, K.*; Zhang, Z. D.*; Li, B.*
Applied Physics Letters, 123(1), p.011903_1 - 011903_6, 2023/07
Times Cited Count:1 Percentile:54.89(Physics, Applied)