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Oba, Yojiro; Ito, Daisuke*; Saito, Yasushi*; Onodera, Yohei*; Parker, J. D.*; Shinohara, Takenao; Oikawa, Kenichi
Materials Research Proceedings, Vol.15, p.160 - 164, 2020/02
Lead Bismuth eutectic (LBE) is a promising candidate of the coolant for accelerator driven system (ADS) and fast breeder reactor. Neutron transmission imaging is a powerful technique to investigate the LBE in flow channel. However, previous studies have focused on the analysis of the neutron transmission spectra due to Bragg diffraction (Bragg edge transmission) from the solid phase of the LBE. If the neutron transmission spectra due to the diffraction from a liquid phase can be observed, it is useful to study the behavior of the molten LBE in the flow channel. Therefore, the energy-resolved neutron transmission imaging measurements of the molten LBE was carried out. The observed neutron transmission spectra can be explained by those calculated from the scattering profiles of the molten LBE. This indicates that the structure of the molten LBE can be characterized and mapped using the neutron transmission imaging.
Phan, L. H. S.*; Ohara, Yohei*; Kawata, Ryo*; Liu, X.*; Liu, W.*; Morita, Koji*; Guo, L.*; Kamiyama, Kenji; Tagami, Hirotaka
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 12 Pages, 2018/10
Self-leveling behavior of core fuel debris beds is one of the key phenomena for the safety assessment of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The SIMMER code has been developed for CDA analysis of SFRs, and the code has been successfully applied to numerical simulations for key thermal-hydraulic phenomena involved in CDAs as well as reactor safety assessment. However, in SIMMER's fluid-dynamics model, it is always difficult to represent the strong interactions between solid particles as well as the discrete particle characteristics. To solve this problem, a new method has been developed by combining the multi-fluid model of the SIMMER code with the discrete element method (DEM) for the solid phase to reasonably simulate the particle behaviors as well as the fluid-particle interactions in multi-phase flows. In this study, in order to validate the multi-fluid model of the SIMMER code coupled with DEM, numerical simulations were performed on a series of self-leveling experiments using a gas injection method in cylindrical particle beds. The effects of friction coefficient on the simulation results were investigated by sensitivity analysis. Though more extensive validations are needed, the reasonable agreement between simulation results and corresponding experimental data preliminarily demonstrates the potential ability of the present method in simulating the self-leveling behaviors of debris bed. It is expected that the SIMMER code coupled with DEM is a prospective computational tool for analysis of safety issues related to solid particle debris bed in SFRs.
Oba, Yojiro; Shinohara, Takenao; Sato, Hirotaka*; Onodera, Yohei*; Hiroi, Kosuke; Su, Y. H.; Sugiyama, Masaaki*
Journal of the Physical Society of Japan, 87(9), p.094004_1 - 094004_5, 2018/09
Times Cited Count：1 Percentile：11.06(Physics, Multidisciplinary)no abstracts in English
Kawata, Ryo*; Ohara, Yohei*; Sheikh, Md. A. R.*; Liu, X.*; Matsumoto, Tatsuya*; Morita, Koji*; Guo, L.*; Kamiyama, Kenji; Suzuki, Toru
Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 14 Pages, 2017/09
He neutron spin filters on the small-angle neutron scattering spectrometer SANS-J-IISakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Aizawa, Kazuya; Arai, Masatoshi; Noda, Yohei; et al.
Journal of Physics; Conference Series, 294(1), p.012017_1 - 012017_7, 2011/06
Times Cited Count：2 Percentile：64.62(Physics, Applied)Yanagie, Hironobu*; Kumada, Hiroaki*; Nakamura, Takemi; Higashi, Shushi*; Ikushima, Ichiro*; Morishita, Yasuyuki*; Shinohara, Atsuko*; Fujiwara, Mitsuteru*; Suzuki, Minoru*; Sakurai, Yoshinori*; et al.
Proceedings of 14th International Congress on Neutron Capture Therapy (ICNCT-14) (CD-ROM), p.157 - 160, 2010/10
Chikazawa, Yoshitaka; Kisohara, Naoyuki; Hishida, Masahiko; Fujii, Tadashi; Konomura, Mamoru; Ara, Kuniaki; Hori, Toru*; Uchida, Akihito*; Nishiguchi, Yohei*; Nibe, Nobuaki*
JAEA-Research 2006-049, 75 Pages, 2006/07
JAEA-Research-2006-049.pdf:4.55MB
In the feasibility study on commercialized fast breeder cycle system, a medium scale sodium cooled reactor with 750MW electricity has been designed. In this study, EMPs are applied to the secondary sodium main pump. The EMPs type is selected to be an annular linear induction pump (ALIP) type with double stators which is used in the 160m
/min EMP demonstration test. The inner structure and electromagnetic features are decided reviewing the 160m/min EMP. Two dimensional electromagnetic fluid analyses by EAGLE code show that Rms (magnetic Reynolds number times slip) is evaluated to be 1.08 which is less than the stability limit 1.4 confirmed by the 160m/min EMP test, and the instability of the pump head is evaluated to be 3% of the normal operating pump head. Since the EMP stators are cooled by contacting coolant sodium duct, reliability of the inner structures are confirmed by temperature distribution and stator-duct contact pressure analyses. Besides, a power supply system, maintenance and repair feature and R&D plan of EMP are reported.
Murakami, Tsutomu; Hishida, Masahiko; Kisohara, Naoyuki; Hayafune, Hiroki; Hori, Toru; Fujii, Tadashi; Uchita, Masato; Chikazawa, Yoshitaka; Uno, Osamu; Saigusa, Toshiie; et al.
JNC TY9400 2004-014, 78 Pages, 2004/07
JNC-TY9400-2004-014.pdf:7.97MB
This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2003, which is the third year of Phase 2. In the JFY2003 design study, critical subjects related to safety, structural integrity and thermal hydraulics which found in the last fiscal year has been examined and the plant concept has been modified. Furthermore, fundamental specifications of main systems and components have been set and economy has been evaluated. In addition, as the interim evaluation of the candidate concept of the FBR fuel cycle is to be conducted, cost effectiveness and achievability for the development goal were evaluated and the data of the three large-scale reactor candidate concepts were prepared.
Hishida, Masahiko; Murakami, Tsutomu; Kisohara, Naoyuki; Fujii, Tadashi; Uchita, Masato; Hayafune, Hiroki; Chikazawa, Yoshitaka; Hori, Toru; Saigusa, Toshiie; Uno, Osamu; et al.
JNC TY9400 2004-012, 97 Pages, 2004/07
JNC-TY9400-2004-012.pdf:12.55MB
Based on the concept of a plant consisting of four modules with a capacity of 750 MWe each, which has been established by the end of FY2002, a concept of the entire plant was proposed, reflecting the modifications related to the high internal conversion type core, the double-wall straight tube steam generator (SG), and the fuel storage system. Concept studies were also performed to overcome the drawbacks of the sodium and to achieve in-service inspection and repair as easily as in light water reactor. Furthermore, feasibility studies were carried out to confirm the design, which included safety, thermal-hydraulics and the structures of the primary reactor auxiliary cooling system and the double-wall straight tube SG. A prospect for realization of this plant concept has been obtained through the evaluation results. In addition, as the interim evaluation of the candidate concepts of the FBR fuel cycle is to be conducted, cost effectiveness and achievability for the development goal were evaluated and the data of the three medium-scale reactor candidate concepts were prepared.
Kisohara, Naoyuki; Soman, Yoshindo; Nishiguchi, Yohei; Konomura, Mamoru
JNC TN9400 2003-090, 76 Pages, 2003/10
The conceptual design study of sodium-cooled FBRs is in progress in the "Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)". In this plant system design, a primary sodium pump are placed into an intermediate heat exchanger (IHX) and these two components are installed in one vessel to reduce plant construction cost. The primary sodium pump is located in the center of IHX tube bundle and this pump-IHX component includes primary/secondary sodium flow shrouds, pump-IHX boundary shroud and bellows. Although the pump and IHX are installed in the same vessel, these two components are structurally separated, because they are connected through a bellows and their weights are supported by different floors. However, the vibration caused by pump rotation has possibility to induce the vibration of heat transfer tubes via sodium and it leads the tubes to fretting wear against their support plates. Therefore, the tube fretting wear has been evaluated by both a simple beam vibration analysis model and a detailed shell vibration analysis model. Since the pump-IHX component consists of many different parts such as shrouds and tube bundle, analysis tools cannot reveal the vibration phenomena precisely. Then the analysis model requires to be validated by vibration tests. A 1/4-scale vibration test equipment of the whole pump-IHX component has been planned to confirm the occurrence and transmission of vibration. This test equipment is precisely minimized based on the actual pump-IHX component structure except the tube bundle. Acceleration sensors are installed on the shrouds to measure beam and shell vibration phenomena, and the signal will be used to reveal vibration modes and pump response properties. The fabrication of the test equipment was completed in FY2002 except the pump. In FY2003 the vibration tests are being executed by using electromagnetic vibrator instead of the pump. In FY2005, the pump will be settled into the test equipment, and the vibration tes
Kisohara, Naoyuki; Hishida, Masahiko; Nibe, Nobuaki; Hori, Toru; Fujii, Tadashi; Uchita, Masato; Chikazawa, Yoshitaka; Saigusa, Toshiie; Uno, Osamu; Soman, Yoshindo; et al.
JNC TY9400 2003-015, 103 Pages, 2003/09
JNC-TY9400-2003-015.pdf:6.39MB
In Phase I of the "Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)", an advanced loop type reactor has been selected as a promising concept of sodium-cooled middle-scale modular reactor, which has a possibility to fulfill the design requirements of the F/S. This report summarizes the results of the design study on the sodium-cooled middle-scale modular reactor performed in JFY2002, which is the second year of Phase 2. The construction cost of the sodium-cooled middle-scale modular reactor, which has been constructed in JFY2002, was almost achieved the economical goal. But its achievability was not sufficient to accept the concept. In order to reduce the construction cost, the plant concept has been re-constructed based on the 50 MWe plant studied in JFY2002. After that, fundamental specifications of main systems and components for the new concept have been set, and critical subjects have been examined and evaluated. In addition, in order to achieve the further cost reduction, the plant with simplified secondary system, the plant with electric magnetic pump in secondary system, and the fuel handling system are examined and evaluated. As a result of this study, the plant concept of the sodium-cooled middle-scale modular reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000 yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowingdown candidate concepts at the end of Phase 2.
Kisohara, Naoyuki; Hishida, Masahiko; Nibe, Nobuaki; Hori, Toru; Fujii, Tadashi; Uchita, Masato; Chikazawa, Yoshitaka; Saigusa, Toshiie; Uno, Osamu; Soman, Yoshindo; et al.
JNC TY9400 2003-014, 52 Pages, 2003/09
JNC-TY9400-2003-014.pdf:3.12MB
In Phase 2 of the F/S, it is planed to precede a preliminary conceptual design of a sodium-cooled large-scale reactor based on the design of the advanced loop type reactor. Through the design study, it is intended to construct such a plant concept that can show its attraction and competitiveness as a commercialized reactor. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2002, which is the second year of Phase 2. In the JFY2002 design study, critical subjects related to safety, structural integrity and thermal hydraulics which found in the last fiscal year has been examined and the plant concept has been modified. Furthermore, fundamental specifications of main systems and components have been set and economy has been evaluated.As a result of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000yens/kWe, etc.) and has a prospect to solve the critical subjects.
Oba, Yojiro; Ito, Daisuke*; Saito, Yasushi*; Onodera, Yohei*; Parker, J. D.*; Shinohara, Takenao; Oikawa, Kenichi
no journal, ,
With the progress of pulsed neutron techniques, neutron transmission spectroscopy became able to provide the structural information in samples via the neutron attenuation by neutron scattering. This technique is known as the Bragg edge transmission analysis for crystalline materials. The Bragg edge transmission analysis is widely applied to neutron imaging experiments. In contrast, little attention has been paid to the neutron diffraction contributions from liquid and amorphous materials in the neutron transmission spectra. In this study, we measured and analyzed the neutron transmission spectra of liquid lead-bismuth eutectic (LBE) to clarify the relation between the neutron transmission spectra and diffraction profiles of liquid and amorphous materials.
Shibahara, Ryuji*; Asai, Shiho; Hagiwara, Kyohei*; Takami, Michiko*; Shiraishi, Kunio*; Umeno, Daisuke*; Shinohara, Nobuo; Sugo, Takanobu*; Saito, Kyoichi*
no journal, ,
no abstracts in English
Udagawa, Yutaka; Yamaguchi, Masatake; Abe, Hiroaki*; Asari, Keisuke*; Shinohara, Yasunari*; Murakami, Kenta*; Nakazono, Yoshihisa*; Mihara, Takeshi*; Sawayama, Yohei*; Sekimura, Naoto*; et al.
no journal, ,
no abstracts in English
Kumada, Takayuki; Noda, Yohei; Hashimoto, Takeji; Koizumi, Satoshi; Ishikawa, Norito; Ohara, Kota
no journal, ,
We tried to determine distribution of radicals produced by radiolysis of polymer materials using techniques of dynamic nuclear polarization and small-angle neutron scattering.
He neutron spin filters on small-angle neutron scattering spectrometer SANS-J-IISakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Arai, Masatoshi; Noda, Yohei; Koizumi, Satoshi; et al.
no journal, ,
no abstracts in English
He spin filters on small-angle neutron scattering spectrometer SANS-J-IISakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Aizawa, Kazuya; Arai, Masatoshi; Noda, Yohei; et al.
no journal, ,
no abstracts in English
Kawasaki, Yohei*; Granata, G.*; Tokoro, Chiharu*; Ohara, Yoshiyuki
no journal, ,
Arsenic in mine wastewater is an important issue in environmental research. In this study, to better understand the phenomena involved in the removal of arsenic from wastewater, the dynamic behavior of arsenic in the Yotsugi Mill Tailings Pond at Ningyo-toge mine was investigated. By utilizing geosphere fluid modeling software (GETFLOWS), we first reproduced the overall area flow through the advection-dispersion of non-reactive silicate ion with assuming the groundwater inlet. Following this, the total concentrations of arsenic and iron were reproduced by including in the previous advection-dispersion model, the first order kinetics for oxidation of As(III) and Fe(II) along with the precipitation equilibrium of Fe(III) as ferrihydrite. Finally, the adsorption of As(V) or As(III) on ferrihydrite was included in the simulation by considering the surface complexation model previously validated in batch adsorption tests. The results highlighted the natural oxidation of Fe(II) to Fe(III) and the subsequent precipitation of Fe(III) as ferrihydrite. Furthermore, the as-precipitated ferrihydride exhibited a strong ability to remove the arsenic by adsorption. The results also emphasized that the oxidation of As(III) to As(V) and the competitive adsorption between arsenic and the natural phosphates in water, play a key role in the natural removal of the arsenic in the pond.
Kawasaki, Yohei*; Granata, G.*; Tokoro, Chiharu*; Ohara, Yoshiyuki
no journal, ,
