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Asahi, Yuichi*; Latu, G.*; Bigot, J.*; Maeyama, Shinya*; Grandgirard, V.*; Idomura, Yasuhiro
Concurrency and Computation; Practice and Experience, 32(5), p.e5551_1 - e5551_21, 2020/03
Times Cited Count：1 Percentile：13.83(Computer Science, Software Engineering)Two five-dimensional gyrokinetic codes GYSELA and GKV were ported to the modern accelerators, Xeon Phi KNL and Tesla P100 GPU. Serial computing kernels of GYSELA on KNL and GKV on P100 GPU were respectively 1.3x and 7.4x faster than those on a single Skylake processor. Scaling tests of GYSELA and GKV were respectively performed from 16 to 512 KNLs and from 32 to 256 P100 GPUs, and data transpose communications in semi-Lagrangian kernels in GYSELA and in convolution kernels in GKV were found to be main bottlenecks, respectively. In order to mitigate the communication costs, pipeline-based and task-based communication overlapping were implemented in these codes.
Yamamoto, Masahiro; Irisawa, Eriko; Igarashi, Takahiro; Komatsu, Atsushi; Kato, Chiaki; Ueno, Fumiyoshi
Proceedings of Annual Congress of the European Federation of Corrosion (EUROCORR 2019) (Internet), 5 Pages, 2019/09
Intergranular corrosion phenomena were analysed using modified reprocessing solution. The data indicated that corrosion rates increased with time at the initial stage, and these stayed at constant value. Intergranular corrosion propagated at grain boundary in the initial stage and then attacked whole grain boundary causing drop out of grains. Corrosion rates of steady state were sum of intergranular corrosion amounts and weight losses of dropped grains. Surface appearances and cross sections of corroded samples were analyzed. The results indicated that the initial stage of intergranular corrosion was characterized by the ratio of corrosion rates between grain boundary and matrix. These ratios differed from individual grain boundaries. Total corrosion rates were affected by the distribution of these ratios. These data were based on the numerical modelling of intergranular corrosion using cellular automata. And also, calculated results were compared with these analytical data.
Muramatsu, Toshiharu
Dai-89-Kai Reza Kako Gakkai Koen Rombunshu, p.115 - 119, 2018/05
no abstracts in English
Asakura, Toshihide; Hotoku, Shinobu; Ban, Yasutoshi; Matsumura, Masakazu; Morita, Yasuji
Journal of Nuclear and Radiochemical Sciences, 6(3), p.271 - 274, 2005/12
Tc extraction and separation experiments were performed basing on PUREX technique with using spent UO
fuel with burn-up of 44 GWd/t. The experimental results were examined with performing calculations by a simulation code ESSCAR (Extraction System Simulation Code for Advanced Reprocessing). It was demonstrated that Tc can be almost quantitatively extracted from a dissolver solution and that Tc can also be almost quantitatively recovered by scrubbing. Further, it was clearly presented from the calculation results of ESSCAR that the extraction mechanism of Tc is dominated by the synergistic effect of Zr and U.
Research Group for Actinides Science
JAERI-Conf 2005-008, 216 Pages, 2005/09
JAERI-Conf-2005-008.pdf:35.12MB
This report is the Proceedings of the 4th Workshop on Molten Salts Technology and Computer Simulation, which was held on December 20, 2004, at Tokai Research Establishment of Japan Atomic Energy Research Institute (JAERI). The purpose of this workshop is to exchange information and views on molten salts technology and computer simulation among the specialists from domestic organizations, and to discuss the recent and future research status for this research field. The intensive discussion was made among approximately 55 participants. The presentations were 14 papers including one keynote lecture.
Asakura, Toshihide; Sato, Makoto; Matsumura, Masakazu; Morita, Yasuji
JAERI-Conf 2005-007, p.345 - 347, 2005/08
This paper reviews the succeeding development and utilization of Extraction System Simulation Code for Advanced Reprocessing (ESSCAR). From the viewpoint of development, more tests with spent fuel and calculations should be performed with better understanding of the physico-chemical phenomena in a separation process. From the viewpoint of process safety research on fuel cycle facilities, it is important to know the process behavior of a key substance; being highly reactive but existing only trace amount.
Azumi, Masafumi
Purazuma, Kaku Yugo Gakkai-Shi, 80(5), p.378 - 381, 2004/05
Progress of large scale scientific simulation environment in JAERI is briefly described. The expansion of fusion simulation science have been played a key role in the increasing performances of super computers and computer network system in JAERI. Both scalar parallel and vector parallel computer systems are now working in Naka and Tokai sites respectively and, particle and fluid simulation codes developed under the fusion simulation project, NEXT, are running on each system. The storage grid system has been also successfully developed for the effective visualization analysis by remote users. Fusion research is going to enter the new phase of ITER, and the need for the super computer system with higher performance are increasing more than as ever along with the development of reliable simulation models.
Minato, Kazuo; Hayashi, Hirokazu; Mizuguchi, Koji*; Sato, Takeyuki*; Amano, Osamu*; Miyamoto, Satoshi*
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.778 - 781, 2003/11
The simulation technology for the pyrochemical reprocessing of oxide fuels was developed to analyze experimental data, to predict experimental results, and to propose adequate conditions and processes. The simulation method was based on calculations of chemical equilibrium and electrochemical reactions. Some model calculations to simulate the experimental results were made on the process of electro-codeposition of UO and PuO. Although it was difficult to trace the experiments and compare the calculated results with the experimental results quantitatively due to the limitation of available data on the experimental conditions, the calculated results were consistent with the experimental results. The phenomena of the repeated oxidation-reduction reactions between Pu
and Pu
ions and those between Fe and Fe
ions were theoretically analyzed,which caused the low current efficiency in the electro-codeposition process.
Hotoku, Shinobu; Asakura, Toshihide; Mineo, Hideaki; Uchiyama, Gunzo
Journal of Nuclear Science and Technology, 39(Suppl.3), p.313 - 316, 2002/11
no abstracts in English
Hayashi, Hirokazu; Minato, Kazuo
JAERI-Conf 2001-016, 181 Pages, 2001/12
JAERI-Conf-2001-016.pdf:11.72MB
Applications of molten salts technology to separations and syntheses of materials have been studied eagerly, which would develop new fields of materials science. Research Group for Actinides Science, Department of Materials Science, Japan Atomic Energy Research Institute (JAERI), together with Reprocessing and Recycle Technology Division, Atomic Energy Society of Japan, organized the Workshop on Molten Salts Technology and Computer Simulation at Tokai Research Establishment, JAERI on September 18, 2001. In the workshop eleven lectures were made and lively discussions were there on the bases and applications of the molten salts technology that covered the structure and basic properties of molten salts, the pyrochemical reprocessing technology and the relevant computer simulation.
Higuchi, Kenji; Hasegawa, Yukihiro*; Hirayama, Toshio
JAERI-Review 2000-019, 70 Pages, 2000/12
JAERI-Review-2000-019.pdf:1.89MB
no abstracts in English
*; *;
JAERI-Data/Code 96-031, 53 Pages, 1996/11
JAERI-Data-Code-96-031.pdf:1.82MB
no abstracts in English
10, 1995, JAERI, Tokai, Japan; Research Committee on Reactor Physics
JAERI-Conf 96-002, 160 Pages, 1996/02
no abstracts in English
; Higuchi, Kenji; ; Harada, Hiro; ; *; *
High Performance computing 1995; Grand Challenges in Computer Simulation, 0, p.9 - 15, 1995/00
no abstracts in English
; Higuchi, Kenji; ; Kume, Etsuo; ; Ebihara, Kenichi; Otani, Takayuki
JAERI-M 94-051, 109 Pages, 1994/03
no abstracts in English
Fujine, Sachio; Tachimori, Shoichi; ; Suzuki, Shinichi; Maeda, Mitsuru; *; *
Proceedings of 4th International Conference on Nuclear Fuel Reprocessing and Waste Management; RECOD '94, Vol.1, 0, 14 Pages, 1994/00
no abstracts in English
; Higuchi, Kenji; ; Kume, Etsuo; ; Ebihara, Kenichi
JAERI-M 92-198, 129 Pages, 1993/01
no abstracts in English
7, 1992 Mito Plaza Hotel, Mito, Ibaraki, Japan: JAERI-CONF 1JAERI-M 92-207, 645 Pages, 1992/12
no abstracts in English
; ; Higuchi, Kenji; Kume, Etsuo; Otani, Takayuki; B.H.Fair*; ;
JAERI-M 91-101, 176 Pages, 1991/06
no abstracts in English
