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Takai, Toshihide; Furukawa, Tomohiro; Yamano, Hidemasa
Nuclear Technology, 205(9), p.1164 - 1174, 2019/09
Times Cited Count:7 Percentile:61.18(Nuclear Science & Technology)Suzuki, Kiichi; Kato, Masato; Sunaoshi, Takeo*; Uno, Hiroki*; Carvajal-Nunez, U.*; Nelson, A. T.*; McClellan, K. J.*
Journal of the American Ceramic Society, 102(4), p.1994 - 2008, 2019/04
Times Cited Count:36 Percentile:90.55(Materials Science, Ceramics)The fundamental properties of CeO were assessed using a range of experimental techniques. The oxygen potential of CeO was measured by the thermogravimetric technique, and a numerical fit for the oxygen potential of CeO is derived based on defect chemistry. Mechanical properties of CeO were obtained using sound velocity measurement, resonant ultrasound spectroscopy and nanoindentation. The obtained mechanical properties of CeO are then used to evaluate the Debye temperature and Gruneisen constant. The heat capacity and thermal conductivity of CeO were also calculated using the Debye temperature and the Gruneisen constant. Finally, the thermal conductivity was calculated based upon laser flash analysis measurements. This result demonstrates that the thermal conductivity has strong dependence upon material purity.
Kawaguchi, Munemichi; Miyahara, Shinya; Uno, Masayoshi*
Netsu Sokutei, 45(1), p.2 - 8, 2018/01
Liquid sodium (Na) has been used as the coolant of fast reactors for the various merits, such as the high thermal conductivity. On the other hand, it is postulated that a steel liner may fail and lead to a sodium-concrete reaction (SCR) during the Na-leak accident. Because of concrete ablation and release of hydrogen gas due to the chemical reactions between Na and concrete components, the SCR is one of the important phenomena in the Na-leak accident. In the study, fundamental experiments related to the SCR were performed using Na and concrete powder. Here, the used concrete powder is milled siliceous concrete which is usually used as the structural concrete in Japanese nuclear power plants. The obvious temperature changes at 3 temperature regions were observed for the reaction process such as Na-melt, NaOH-SiO and Na-HO-SiO reaction, which occurred around 100, 300 and 500C, respectively. Especially, the violent reaction around 500C caused the temperature peak to C, and the reaction heat of kW/g was estimated under the Na-concrete mixing ratio such as . The main components of the reaction products was identified as NaSiO with X-ray diffraction technique. Moreover, the measured thermophysical properties such as melting point, density, specific heat, thermal conductivity and viscosity were similar to those of NaO-SiO ().
Eguchi, Yuta; Sugawara, Takanori; Nishihara, Kenji; Tazawa, Yujiro; Inoue, Akira; Tsujimoto, Kazufumi
JAEA-Technology 2015-052, 34 Pages, 2016/03
Transmutation Physics Experimental Facility (TEF-P) planned in the J-PARC project uses minor actinide (MA) fuel which has large decay heat. So it is necessary to consider the increase of the core temperature when the core cooling system is stopped. This change of the core temperature was evaluated by thermal conduction analysis. It was found that the impact of thermal insulation in the empty rectangular lattice matrix area was large. So it is necessary to verify reliability and accuracy of heat transfer effect used in this area. Testing equipment was fabricated to verify the accuracy of calculation model for the empty lattice matrix which was the free convection model of sealed fluid. By using this equipment, thermal distribution and one dimensional heat flow through the lattice were measured. It was observed that the actual equivalent thermal conductivity in the lattice was larger than the free convection model. It was also confirmed that the insertion of the aluminum block into the empty lattice could achieve the higher equivalent thermal conductivity. These results could be the useful data for the thermal conduction analysis.
Suzuki, Satoshi; Enoeda, Mikio; Hatano, Toshihisa; Hirose, Takanori; Hayashi, Kimio; Tanigawa, Hisashi; Ochiai, Kentaro; Nishitani, Takeo; Tobita, Kenji; Akiba, Masato
Nuclear Fusion, 46(2), p.285 - 290, 2006/02
Times Cited Count:2 Percentile:7.04(Physics, Fluids & Plasmas)This paper presents significant progress in R&D of key technologies on the water-cooled solid breeder blanket for the ITER-TBM in JAERI. By the improvement of heat treatment process for blanket module fabrication, a fine-grained microstructure of F82H, can be obtained by homogenizing it at 1150 C followed by normalizing at 930 C after the HIP process. Moreover, a promising bonding process for a tungsten armor and an F82H structural material was developed by using a uniaxial hot compression without any artificial compliant layer. Also, it has been confirmed that a fatigue lifetime correlation, which was developed for ITER divertor, can be applicable for F82H first wall mock-up. As for R&D on a breeder material, LiTiO, the effect of compression loads on thermal conductivity of pebble beds has been clarified. JAERI have extensively developed key technologies for ITER-TBM, and now steps up into an engineering R&D stage, where integrated performance of TBM structures will be demonstrated by scalable mock-ups.
Shiina, Yasuaki; Inagaki, Terumi*
International Journal of Heat and Mass Transfer, 48(2), p.373 - 383, 2005/01
Times Cited Count:37 Percentile:75.29(Thermodynamics)Improvement of thermal conductivity of phase change medium would be one of the effective techniques to reduce phase change time in latent heat storage technology. Thermal conductivity would be improved by saturating phase change materials (PCM) in porous metals. Efficiency of effective thermal conductivity on melting time is studied by analyzing melting characteristics of a heat storage circular capsule where porous metal saturated by PCM is inserted. Results show that considerable reduction in melting time was obtained, especially for low conductivity PCMs and for high heat transfer coefficient. Trial estimation of optimum porosity was presented under the conditions of keeping high latent heat capacity and high reduction rate of melting time. Optimum porosity decreases with increase in heat transfer coefficient.
Kurihara, Ryoichi
Fusion Engineering and Design, 61-62, p.209 - 216, 2002/11
Times Cited Count:4 Percentile:29.2(Nuclear Science & Technology)To attain high fusion power density, the divertor must suffer high heat flux from the fusion plasma. It is very difficult to remove a high heat flux more than 20 MW/m using the only solid divertor plate from the viewpoint of severe mechanical state such as thermal stress and crack growth. Therefore, a concept of liquid divertor is proposed to remove high heat flux by liquid films flowing on a solid wall. This paper mainly descries a preliminary thermofluid analysis of the free surface liquid flow, made of the FliBe molten salt, using the finite element analysis code ADINA-F. The heat flux of 25100 MW/m was given on the free surface liquid of the flow. I explored a possibility of applying the secondary flow to enhance the heat transfer of the liquid flow suffering high heat flux. This analysis shows that the heat flux of 100 MW/m can be removed by inducing the secondary flow in the free surface liquid FLiBe. And this paper shows that the liquid divertor using solid-liquid multi-phase flow makes possible large heat removal by utilizing the latent heat of fusion of solid phase.
Wan, C.*; Motohashi, Yoshinobu*; Shibata, Taiju; Baba, Shinichi; Ishihara, Masahiro; Hoshiya, Taiji
Materials Transactions, 43(10), p.2473 - 2479, 2002/10
Times Cited Count:14 Percentile:62.96(Materials Science, Multidisciplinary)no abstracts in English
Shirasu, Yoshiro; Minato, Kazuo
Proc. of the Int. Conf. on Future Nuclear Systems (GLOBAL'99)(CD-ROM), 7 Pages, 1999/00
no abstracts in English
Minato, Kazuo; Shirasu, Yoshiro
Proceedings of 2nd Japanese-Russian Seminar on Technetium, p.77 - 78, 1999/00
no abstracts in English
Minato, Kazuo; Serizawa, Hiroyuki; Fukuda, Kosaku
Journal of Alloys and Compounds, 267, p.274 - 278, 1998/00
Times Cited Count:7 Percentile:49.87(Chemistry, Physical)no abstracts in English
Minato, Kazuo; Shirasu, Yoshiro
Proc. of 5th Int. Information Exchange Meeting on Actinide and Fission Product Partitioning, p.223 - 230, 1998/00
no abstracts in English
Hada, Kazuhiko
JAERI-M 93-029, 99 Pages, 1993/03
no abstracts in English
White, J.*; Hirooka, Shun; Murakami, Tatsutoshi; Nelson, A.*; McClellan, K.*; Kato, Masato
no journal, ,
Use of CeO as a surrogate to better understand the behavior of MOX fuels requires a fundamental investigation of the thermophysical properties to assess the appropriate use. The challenge in performing thermophysical property measurements on oxygen non-toichiometric MOX is in handling the kinetics at elevated temperatures and also in determining a reference state from which to measure the oxygen:metal ratio (O:M). This study integrated the use of identical gas handling systems installed on a thermogravimetric analyzer and the property measurement system (differential scanning calorimeter and laser flash analyzer) to control the partial pressure of oxygen, PO, between the system and maintain stoichiometry from ambient temperature to 1200C.
Eguchi, Yuta; Sugawara, Takanori; Nishihara, Kenji; Tazawa, Yujiro; Tsujimoto, Kazufumi
no journal, ,
Transmutation Physics Experimental Facility (TEF-P) planned in the J-PARC project uses minor actinide (MA) fuel which has large decay heat. So it is necessary to consider the increase of the core temperature when the core cooling system is stopped. This change of the core temperature was evaluated by thermal conduction analysis. It was found that the impact of thermal insulation in the empty rectangular lattice matrix area was large. Testing equipment was fabricated to verify the accuracy of calculation model for the empty lattice matrix which was the free convection model of sealed fluid. By using this equipment, thermal distribution and one dimensional heat flow through the lattice were measured. It was observed that the actual equivalent thermal conductivity in the lattice was larger than the free convection model. It was also confirmed that the insertion of the aluminum block into the empty lattice could achieve the higher equivalent thermal conductivity. These results could be the useful data for the thermal conduction analysis.
Hirooka, Shun; Matsumoto, Taku; Morimoto, Kyoichi; Ogasawara, Masahiro*; Murakami, Tatsutoshi; Kato, Masato
no journal, ,
no abstracts in English