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Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2022-061, 59 Pages, 2023/02
JAEA-Review-2022-061.pdf:2.38MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2021, this report summarizes the research results of the "Research on radioactive aerosol control and decontamination at Fukushima Daiichi Nuclear Power Station decommissioning" conducted in FY2021. The present study aims to develop a safe laser decontamination system that simultaneously incorporates an advanced particle detection and characterization system together with aerosol dispersion control in collaboration with the UK researchers. By using the UK partner's fundamental studies related to aerosol and water interface interactions, various methods such as electro-chemical processing of water-mist particles and spray droplets will be applied for effective control of ultra-fine aerosol particle dispersions in a large containment volume.
Uesawa, Shinichiro; Yoshida, Hiroyuki
Mechanical Engineering Journal (Internet), 7(3), p.19-00539_1 - 19-00539_9, 2020/06
Uesawa, Shinichiro; Miyahara, Naoya; Horiguchi, Naoki; Yoshida, Hiroyuki; Osaka, Masahiko
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 5 Pages, 2019/05
Sugimoto, Taro*; Saito, Shimpei*; Kaneko, Akiko*; Abe, Yutaka*; Uchibori, Akihiro; Ohshima, Hiroyuki
Proceedings of 26th International Conference on Nuclear Engineering (ICONE-26) (Internet), 7 Pages, 2018/07
A computational fluid dynamics code for a sodium-water reaction phenomenon in a steam generator of sodium-cooled fast reactors has been developed. In order to provide the data for validation of this code, the visualization experiment on liquid droplet entrainment in the high-pressure air jet submerged in the water pool was carried out. The experiment successfully elucidated the behavior, such as atomization of the relatively large diameter liquid droplet generated from the gas-liquid interface.
Uchibori, Akihiro; Ohshima, Hiroyuki
Proceedings of 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) (USB Flash Drive), p.533 - 544, 2015/08
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 including the numerical model for liquid droplet entrainment and transport was investigated through the analysis of the basic experiment and the experiment under actual condition of the steam generator. In the analysis of the basic experiment, the calculated pressure variation during liquid droplet entrainment was consistent with the experimental result. In the analysis of the actual condition, the calculated temperature distribution agreed with the measurement result well. 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 wastage environment under the actual condition.
Shibamoto, Yasuteru; Sun, Haomin; Yonomoto, Taisuke
Proceedings of 10th International Topical Meeting on Nuclear Thermal Hydraulics, Operation and Safety (NUTHOS-10) (USB Flash Drive), 10 Pages, 2014/12
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Taguchi, Mitsumasa; Sakai, Takuro; Ohara, Yoshihiro
JAEA-Review 2005-001, TIARA Annual Report 2004, p.293 - 295, 2006/01
Artificial cloud generation experiment was performed using a huge vertical pit located in Kamaishi iron-copper mine to investigate the characteristics of cloud. The physical and chemical properties of individual cloud droplets were examined by microscopic analysis at Kyoto university and micro-PIXE analysis at TIARA. The process of growth of cloud was clarified based on the result on droplet size, its distribution, droplet number concentration, and the change in distribution of chlorine in droplet as the function of size.
Naoe, Takashi; Futakawa, Masatoshi; Oi, Toshiyuki; Ishikura, Shuichi*; Ikeda, Yujiro
Zairyo, 54(11), p.1184 - 1190, 2005/11
High power spallation targets for neutron sources are being developed in the world. Mercury target will be installed at the material science and life facility in J-PARC, which will promote innovative science. The mercury target is subject to the pressure wave caused by the proton bombarding in the mercury. The pressure wave propagation induces the cavitation in mercury that imposes localized impact damage on the target vessel. The impact erosion is a critical issue to decide the lifetime of the target. The electro Magnetic IMpact Testing Machine, MIMTM, was developed to reproduce the localized impact erosion damage and evaluate the damage formation. Additionally, droplet impact analysis was carried out to investigate the correlation between isolate pit profile and micro-jet velocity. We confirmed that value of depth/radius was able to estimate micro jet-velocity. And the velocity at 560W in MIMTM was estimated to be 225
325 m/s. Furthermore, surface-hardening treatments were inhibited pit formation in plastic deformation.
Watanabe, Tadashi
Proceedings of 11th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-11) (CD-ROM), 8 Pages, 2005/10
no abstracts in English
Ebihara, Kenichi
JAERI-Research 2005-004, 121 Pages, 2005/03
JAERI-Research-2005-004.pdf:19.79MB
This report is the JAERI's report version of the doctor thesis by the author. In this report, first, the validity and usefulness of the application of the two-phase fluid model of the lattice-gas method and the lattice Boltzmann method(LBM) are examined. On the basis of the examination, next, the horizontal stratified two-phase flow that is the fundamental and important flow is simulated by the HCZ model which is one of the two-phase fluid model of the LBM. It is seen that the interfacial growth of the HCZ model satisfies the Kelvin-Helmholtz instability theory and reproduces the theoretical two-phase flow regime map of Taitel and Dukler(T-D map). It is found that more superficial flow velocity of the rare phase is necessary in the channel with the narrow width. The HCZ model can also simulate the droplet generation accompanying more complex interfacial phenomena and reproduce the experimental correlation of Ishii and Grolmes in the range of the distribution of the experimental data.
Ebihara, Kenichi
Tsukuba Daigaku Daigakuin Shisutemu Joho Kogaku Kenkyuka Hakase Gakui Rombun, 134 Pages, 2004/09
In this thesis, first the liquid-gas models of the lattice method are examined by applying them to two-phase flow simulations. Next the liquid-gas model(the HCZ model) of the lattice Boltzmann method is applied to the three-dimensional simulation of the horizontal stratified two-phase flow. The following results are obtained. (1)The two- and three- dimensional interface simulated by the HCZ model satisfies the Kelvin-Helmholtz instability theory. (2)In the simulation of the interfacial growth in the rectangular channel, it is found that the relation between the interfacial growth and the flow state is in agreement with the flow regime map proposed theoretically by Taitel and Dukler. (3)It is also found that the three dimensionality becomes remarkable and the interfacial growth needs more flow rate of the rare phase than that of the theoretical flow regime map when the channel width is narrower. (4)In the droplet creation simulation, it is found that the relation between the droplet creation and the flow state simulates the experimental correlation proposed by Ishii and Grolmes.
Ebihara, Kenichi; Watanabe, Tadashi
Nagare, 23(4), p.253 - 261, 2004/08
The lattice Boltzmann method for one-component two-phase fluid is applied to the simulation of the droplet creation in the horizontal stratified two-phase flow. It is observed in several flow states that the droplet tears from the interface wave. The dimensionless numbers that characterize the flow state are also measured during the simulations. After checking the influence of the lattice length and width to the simulation result, the relation between the droplet creation and the measured dimensionless numbers is compared with the inception criteria of the droplet creation that was proposed on the basis of experimental data by Ishii and Grolmes. It was found that the simulation results are included in the devitation of experimental data from the correlation of Ishii-Grolmes.
Maruyama, Yu*; Moriyama, Kiyofumi; Nakamura, Hideo
Journal of Nuclear Science and Technology, 39(8), p.854 - 864, 2002/08
Times Cited Count：4 Percentile：29.25(Nuclear Science & Technology)no abstracts in English
Date, Hidefumi*; Futakawa, Masatoshi; Ishikura, Shuichi*
Jikken Rikigaku, 2(2), p.103 - 108, 2002/06
In order to examine the impact behavior of mercury, which is one of important key-issues in a facility for high intensity neutron sources, the falling and colliding profiles of mercury droplets were recorded by high-speed video recorder. The impact force was also measured using the strain gage glued on an elastic bar. The falling mercury droplet oscillated between a prolate spheroid and an oblate one, repeatedly. The regathering and jumping of mercury at the collision point on the impact face of the target were observed after impact because of the strong surface tension of mercury. The impact force of mercury droplet was in proportion to the impact velocities and the square root of the potential energy. Scince the non-dimensional duration time K that obtained experimentally is independent of the impact velocity and the size of the droplet, the mean applied stress due to the mercury droplet against the target is easily predictable by the equatiion using K value and the impact velocity is known.
Kataoka, Isao*; Matsuura, Keizo*; Yoshida, Kenji*
JAERI-Tech 2002-015, 83 Pages, 2002/03
JAERI-Tech-2002-015.pdf:3.62MB
no abstracts in English
A.R.Antariksawan*; Moriyama, Kiyofumi; H.Park*; Maruyama, Yu; Y.Yang*; Sugimoto, Jun
JAERI-Review 98-012, 66 Pages, 1998/09
JAERI-Review-98-012.pdf:3.36MB
no abstracts in English
; Koizumi, Yasuo; Tasaka, Kanji
Nucl.Eng.Des., 102, p.71 - 84, 1987/00
Times Cited Count：18 Percentile：83.5(Nuclear Science & Technology)no abstracts in English
; Koizumi, Yasuo; ; Osakabe, Masahiro; Tasaka, Kanji
Nucl.Eng.Des., 96, p.81 - 94, 1986/00
Times Cited Count：3 Percentile：40.89(Nuclear Science & Technology)no abstracts in English
; Murao, Yoshio
JAERI-M 84-131, 223 Pages, 1984/06
no abstracts in English
Osakabe, Masahiro; ;
JAERI-M 83-022, 26 Pages, 1983/02
no abstracts in English
