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Toguri, Satohito*; Okihara, Mitsunobu*; Tsuji, Masakuni*; Nakashima, Hitoshi*; Sugiyama, Hirokazu*; Saito, Akira*; Sato, Toshinori; Aoyagi, Kazuhei; Masunaga, Kosuke
JAEA-Research 2017-013, 131 Pages, 2018/02
JAEA-Research-2017-013.pdf:8.49MB
The discussions on scientifically promising site for the geological disposal has been made at the council of studying group on techniques for geological disposal of radioactive wastes, which is held by Resources and Energy Agency. From the aspect of ensuring safety during the transportation of disposal waste, the coastal area is discussed to be a more suitable area. This report shows the result of the first year of this project as following items; Study on the state-of-art technology and remain tasks; laboratory tests on characterization of colloidal silica grout under sea water; Study on the development of grouting technology (design and the evaluation method of influence on the rock mass).
Terada, Atsuhiko; Matsumoto, Masaaki*; Sugiyama, Hitoshi*; Kamiji, Yu; Hino, Ryutaro
Proceedings of 6th International Conference on Hydrogen Safety (ICHS 2015) (CD-ROM), 11 Pages, 2015/10
To improve the safety performance of the Nuclear Power Station, especially on the hydrogen safety under severe accident conditions, a simulation code system has been developed to analyze hydrogen behavior including diffusion, combustion, explosion and structural integrity evaluation. This developing system consists of CFD and FEM tools in order to support various hydrogen user groups consisting of students, researchers and engineers. Preliminary analytical results obtained with above mentioned tools, especially with open source codes including buoyancy turbulent model and condensation model, agreed well with the existing test data.
Terada, Atsuhiko; Matsumoto, Masaaki*; Sugiyama, Hitoshi*; Kamiji, Yu; Kadowaki, Satoshi*; Hino, Ryutaro
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05
In the Fukushima Daiichi Nuclear Power Station (NPS) accident, hydrogen was generated by oxidation reaction of the cladding and water etc, then leaked into the NPS building, and finally led to occurrence of hydrogen explosion in the building. This resulted in serious damage to the environment. To improve the safety performance of the NPS, especially on the hydrogen safety under severe accident conditions, a simulation code system has been developed to analyze hydrogen behaviors including diffusion, combustion, explosion and structural integrity evaluation. This developing system consists of CFD and FEM tools in order to support various hydrogen user groups of students, researchers and engineers. Preliminary calculated results obtained with above mentioned tools, damage of piping induced by hydrogen combustion, agreed well with existing test data.
Sugiyama, Hitoshi*; Takahashi, Keita*; Kato, Naoto*; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro
Jidosha Gijutsukai Gakujutsu Koenkai Zensatsushu, (109-14), p.5 - 10, 2014/10
Numerical analysis has been performed for vertical buoyant flow of air-hydrogen mixture in rectangular indoor space with ventilators. The unsteady and laminar flow has been calculated by using the coupled conservation equations of hydrogen and momentum. Calculated results are compared with the experiment data of hydrogen concentration and velocity profile in order to confirm the validity of the presented numerical method and clarify the mechanism of hydrogen dispersion. Although agreement is certainly not perfect in all detail, the main features are reasonably reproduced. Adding to this, calculated results suggest that hydrogen concentration depends on Froude number.
Sugiyama, Hitoshi*; Otemori, Toshiki*; Kato, Naoto*; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro
Jidosha Gijutsukai Gakujutsu Koenkai Zensatsushu, (147-14), p.25 - 30, 2014/10
Numerical analysis has been performed for three-dimensional developing turbulent flow in a rectangular duct containing straight cylinder placed near a bottom wall. In this kind of turbulent flow, it has been pointed out as a characteristic features that anisotropic turbulence generates the secondary flow of the second kind and pulsation flow is measured in narrow gap region located between cylinder and bottom wall. Comparisons with the experimental results suggest that the present method is able to predict velocity profiles correctly and reproduce both the secondary flow of the second kind and the generation of pulsation flow near the narrow region between cylinder and bottom wall.
Okagaki, Yuria*; Sugiyama, Hitoshi*; Kato, Naoto*; Hino, Ryutaro
Jidosha Gijutsukai Rombunshu, 43(4), p.949 - 955, 2012/07
Turbulent heat transfer enhancement using periodically arranged ribs processed on the graphite sleeve of a fuel rod aims to increase heat generation density of the fuel rod, which can potentially improve the economics of a block type high-temperature gas-cooled reactor. Rectangular cross section of rib is selected because of easy processing. Furthermore, it is important to find optimum rib topology such as pitch and height to maximize turbulent heat transfer performance. In order to develop a turbulent model as a design tool for rib-roughened fuel rod, numerical analysis has been conducted to verify applicability of an algebraic Reynolds stress model, which is computationally efficient, to non-isotropic turbulent flow in rib roughened channels. The results of the analysis on a square duct with periodically arranged ribs on the bottom wall are shown to reproduce very well the flow characteristics such as flow separation and reattachment behind the ribs. The model is therefore expected to be applicable to rib-enhanced fuel rod design.
Kamiji, Yu; Terada, Atsuhiko; Sugiyama, Hitoshi*
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 7 Pages, 2011/10
Japan Atomic Energy Agency (JAEA) has been conducting R&D on heat utilizing system of High Temperature Gas-cooled Reactor (HTGR). Toward the lower energy consumption and cost reduction of system, we think it is effective to develop waste heat recovery technology. For hydrogen production by thermochemical iodine sulfur process (IS process) which is considered as one of the heat utilization, temperature control unit is an important factors for stable process system driving. Authors focused gas-mixing temperature control and proceeded to design high performance compact unit for process recuperators. From experimental results, in the case of door opening inclining toward flow, there was quite high turbulent kinetic energy up to 3.0U
because of effects of turbulence from separation at tip of the door. Additionally in that door opening, heated flow partially goes to door, so that mixture starts in upstream of mixing region and temperature diffusion gets quite active.
Okagaki, Yuria*; Sugiyama, Hitoshi*; Kato, Naoto*; Terada, Atsuhiko; Hino, Ryutaro
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 8 Pages, 2011/10
Turbulent flow and heat transfer characteristics in a square duct of 100 mm height with 45 degree square ribs of 10 mm height was analyzed numerically by using algebraic Reynolds stress model including the fixed turbulent Prandtl number and algebraic turbulent heat flux models. In this research, analytical results were compared with the experimental and predicted data reported by Bonhoff et al, which were measured and analyzed turbulent flow fields at Reynolds number 50000 based on bulk velocity and duct height by means of a PIV system and a Reynolds stress model. As a result of this study, it was verified that the presented method was able to predict turbulent flow in duct with ribs through the comparison of calculated results with the experimental data.
Okagaki, Yuria*; Sugiyama, Hitoshi*; Hino, Ryutaro; Kato, Naoto*; Terada, Atsuhiko
Nihon Kikai Gakkai Kanto Shibu Burokku Godo Koenkai Koen Rombunshu, p.35 - 36, 2011/09
Turbulent flow and heat transfer characteristics in a square duct of square ribs was analyzed numerically by using algebraic Reynolds stress model. In this research, as the first step of design code development for HTGR heat exchanger equipment, analytical results were compared with the experimental and predicted data reported by Casarsa et al., which were measured by means of a PIV system.
Kamiji, Yu; Terada, Atsuhiko; Sugiyama, Hitoshi*
Nihon Kikai Gakkai Kanto Shibu Yamanashi Koenkai (2010) Koen Rombunshu, p.98 - 99, 2010/10
The Japan Atomic Energy Agency (JAEA) has been conducting simulation design study on process gas reactor for one of the heat utilization system components development of HTGR (High Temperature Gas-cooled Reactor). But, numerical analysis of gas-mixing turbulent flow in reactor is difficult. Also, it is lack of experimental results for verification of the numerical analysis model featured this flow field. Therefore, in order to obtain the experimental data to verify this analysis model, it was carried out that an experimental study in bent rectangular duct with flow control door by using PIV (Particle Image Velocimetry). As a result of this study, it was obtained representative velocity distribution data at the vertical cross section of the duct.
Terada, Atsuhiko; Hino, Ryutaro; Hirayama, Toshio; Nakajima, Norihiro; Sugiyama, Hitoshi*
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 6 Pages, 2007/04
The Japan Atomic Energy Agency has been conducting study on thermochemical IS process for water splitting hydrogen production. Based on the test results and know-how obtained through the bench-scale test, a pilot test plant, which has a hydrogen production performance of 30 Nm
/h, is being designed conceptually as the next step of the IS process development. In design of the IS pilot plant, it is important to make chemical reactors compact with high performance from the viewpoint of plant cost reduction. A new hydraulic analytical code has been developed for optimizing mixing performance of multi-phase flow involving chemical reactions especially in the Bunsen reactor. Preliminary analytical results obtained with above mentioned code, especially flow patterns induced by swirling flow agreed well with that measured by water experiments, which showed vortex breakdown pattern in a simplified Bunsen reactor.
Terada, Atsuhiko; Hino, Ryutaro; Sugiyama, Hitoshi*
Nihon Kikai Gakkai Kanto Shibu Dai-13-Ki Sokai Koenkai Koen Rombunshu, p.501 - 502, 2007/03
In the Japan Atomic Energy Agency (JAEA), a pilot test program has initiated to produce hydrogen at a rate of up to 30 Nm/hr by using thermo-chemical water splitting method by the iodine and sulfur (IS) process. Chemical reactors of the pilot test plant are necessary to be optimized through analytical design works. JAEA is developing a multi-phase analysis code coupled with chemical reaction to design chemical reactors especially for the Bunsen reaction. The new developing code predicted swirl flow pattern with vortex breakdown shown by flow visualization in a cylindrical vessel with rotating bottom surface.
Kanamori, Masashi; Kawata, Tomio; Hitoshi, Watanabe,; Tobita, Yoshiharu; Sugiyama, Toshihide; Miyabe, Kenjiro; Kobayashi, Hirohide
JNC TN8450 2003-009, 506 Pages, 2004/03
JNC-TN8450-2003-009.pdf:14.21MB
This paper describes all the activities that were executed by JNC related to JCO criticality accident on September 30,1999. During the JCO accident, the activities of radiation monitoring, environmental monitoring, criticality termination operation, computer simulation of criticality accident, whole body exposure measurements by WBC about 24-Na, back up of local government like consultation of residents near by were performed by JNC. After the accident Japanese government and Nuclear Safety Commission establishes the investigation committee of JCO accident. JNC has also back up this activity. For example, investigation of the causes, accident scenario, estimation of the doses of the workers and personnel for deserter, counter measure operation. This paper summarizes all the important activity executed by JNC in the meantime.
Kubo, Shinji; Akino, Norio; Akiyama, Mitsunobu*; *
Netsu Bussei, 11(2), p.39 - 45, 1997/00
no abstracts in English
Kubo, Shinji; Akino, Norio; Akiyama, Mitsunobu*; *
Kashika Joho Gakkai-Shi, 15(SUPPL.1), p.63 - 66, 1995/07
no abstracts in English
Kubo, Shinji; Akino, Norio; Akiyama, Mitsunobu*; *
Dai-31-Kai Nihon Dennetsu Shimpojiumu Koen Rombunshu, 0, p.373 - 375, 1994/05
no abstracts in English
Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Matsumoto, Masaaki*; Sugiyama, Hitoshi*; Kadowaki, Satoshi*
no journal, ,
To further improve the safety performance of the Nuclear Power Station, especially on the hydrogen safety under severe accident conditions, a simulation code system has been developed to analyze hydrogen behaviors including diffusion, combustion, explosion and structural integrity evaluation. Preliminary calculated results obtained with above mentioned tools agreed well with ISP47 TOSQAN test data of OECD/NEA project.
Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Sugiyama, Hitoshi*; Matsumoto, Masaaki*; Kadowaki, Satoshi*
no journal, ,
no abstracts in English
Terada, Atsuhiko; Ezure, Takumi*; Hino, Ryutaro; Sugiyama, Hitoshi*; Takase, Kazuyuki*
no journal, ,
A new type passive autocatalytic recombiner has been developed, as one of hydrogen safety managements for waste storage. In this report, thermal hydraulic analysis show PAR concept proposed is feasible for hydrogen mitigation in small scale test.
Terada, Atsuhiko; Hino, Ryutaro; Sugiyama, Hitoshi*; Kato, Naoto*; Takase, Kazuyuki*
no journal, ,
A new type passive autocatalytic recombiner has been developed, as one of hydrogen safety managements for waste storage. In this report, thermal hydraulic analysis show PAR concept proposed is feasible for hydrogen mitigation in waste container.
