Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nakamura, Satoshi; Ishii, Sho*; Kato, Hitoshi*; Ban, Yasutoshi; Hiruta, Kenta; Yoshida, Takuya; Uehara, Hiroyuki; Obata, Hiroki; Kimura, Yasuhiko; Takano, Masahide
Journal of Nuclear Science and Technology, 62(1), p.56 - 64, 2025/01
Times Cited Count：1 Percentile：0.00(Nuclear Science & Technology)A dissolution method for analyzing the elemental composition of fuel debris using the sodium peroxide (Na
O) fusion technique has been developed. Herein, two different types of simulated debris materials (such as solid solution of (Zr,RE)O and molten core-concrete interaction products (MCCI)) were taken. At various temperatures, these debris materials were subsequently fused with NaO in crucibles, which are made of different materials, such as Ni, AlO
, Fe, and Zr. Then, the fused samples are dissolved in nitric acid. Furthermore, the effects of the experimental conditions on the elemental composition analysis were evaluated using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), which suggested the use of a Ni crucible at 923 K as an optimum testing condition. The optimum testing condition was then applied to the demonstration tests with Three Mile Island unit-2 (TMI-2) debris in a shielded concrete cell, thereby achieving complete dissolution of the debris. The elemental composition of TMI-2 debris revealed by the proposed dissolution method has good reproducibility and has an insignificant contradiction in the mass balance of the sample. Therefore, this newly developed reproducible dissolution method can be effectively utilized in practical applications by dissolving fuel debris and estimating its elemental composition.
Sai, Kazunori*; Suzuki, Yoshio; Araki, Fumiaki*; Uehara, Hitoshi*; Haginoya, Hirofumi*
Keisan Kogaku Koenkai Rombunshu, 8(2), p.761 - 764, 2003/05
no abstracts in English
Uehara, Hitoshi; Tamura, Masanori; Yokokawa, Mitsuo
Hai Pafomansu Komputingu To Keisan Kagaku Shimpojium (HPCS2002) Rombunshu, p.73 - 80, 2002/01
The Earth Simulator is an ultra high-speed supercomputer which is developed now for global environment change simulations. For achieving high performance computing on large scale distributed memory parallel computer such as the Earth Simulator, an optimization of communication processings in user applications is required, and the optimization needs an evaluation for performances of communication methods. In the Earth Simulator, Message Passing Interface (MPI) is supported as the communication method. We evaluated performances of the MPI-1/MPI-2 functions on the Earth Simulator in detail using MBL which we developed.
Uehara, Hitoshi; Tsuda, Yoshinori*; Yokokawa, Mitsuo
Joho Shori Gakkai Kenkyu Hokoku 2001-HPC-87, 2001(77), p.67 - 72, 2001/07
MPI is one of major message communication interfaces for application programs. The MPI consists of an MPI-1 as a basic specification, and an MPI-2 as extensions.Some benchmark program for MPI-1 had been proposed already. However benchmark programs for MPI-2 are a little and their measurements are limited. We have developed an MPI benchmark program library for MPI-2 (MBL2) which measures the detail performance of MPI-I/O and RMA functions of MPI-2. In this report, we describe the MBL2 and performance data of MPI-2 on VPP5000, which we measured using MBL2.
Uehara, Hitoshi; Tsuda, Yoshinori*; Yokokawa, Mitsuo
Heiretsu Shori Shimpojiumu (JSPP2001) Rombunshu, 2001(6), p.91 - 92, 2001/06
MPI in one of major message communication interfaces for application programs. The MPI consists of an MPI-1 as a basic specification, and an MPI-2 as extensions. Some benchmark programs for MPI-1 capabilities are proposed. However benchmark programs for MPI-2 are a little and their measurements are limited. We have developed an MPI benchmark program library for MPI-2 (MBL2) which measures the performance of MPI-I/O and RMA.
Uehara, Hitoshi
JAERI-Data/Code 2001-010, 41 Pages, 2001/03
JAERI-Data-Code-2001-010.pdf:2.67MB
Distributed parallel simulation software with message passing interfaces has been developed to realize large-scale and high performance numerical simulations. The most popular API for message communication is an MPI. The MPI will be provided on the Earth Simulator. It is known that performance of message communication by using the MPI libraries gives a significant influence to a whole performance of simulation programs. We developed an MPI benchmark program library named MBL in order to measure the performance of message communication precisely. The MBL measures the performance of major MPI functions such as point-to-point communications and collective communications and the performance of major communication patterns which are often found out in conventional applications. In this report, the description of the MBL and the performance analysis of the MPI/SX measured on the SX-4 are presented.
; ; ; ; ; ; ; Oikawa, Toshihiro; ; ; et al.
Fusion Energy 1996, p.885 - 890, 1997/05
no abstracts in English
Miura, Yukitoshi; ; ; Hoshino, Katsumichi; ; ; Kasai, Satoshi; Kawakami, Tomohide; Kawashima, Hisato; Maeda, M.*; et al.
Fusion Energy 1996, p.167 - 175, 1997/05
no abstracts in English
