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Shimizu, Takeshi*; Wang, H.*; Matsumura, Daiju; Mitsuhara, Kei*; Ota, Toshiaki*; Yoshikawa, Hirofumi*
ChemSusChem, 13(9), p.2256 - 2263, 2020/05
Times Cited Count：24 Percentile：77.17(Chemistry, Multidisciplinary)Shimizu, Takeshi*; Wang, H.*; Tanifuji, Naoki*; Matsumura, Daiju; Yoshimura, Masashi*; Nakanishi, Koji*; Ota, Toshiaki*; Yoshikawa, Hirofumi*
Chemistry Letters, 47(5), p.678 - 681, 2018/05
Times Cited Count：9 Percentile：33.87(Chemistry, Multidisciplinary)
N(n,
)
N reaction as a -ray intensity standard up to 11 MeVMiyazaki, Itaru*; Sakane, Hitoshi*; Takayama, Hirokazu*; Kasaishi, Masafumi*; Tojo, Akinori*; Furuta, Masataka*; Hayashi, Hiroaki*; Suematsu, Osamu*; Narasaki, Hiromichi*; Shimizu, Toshiaki*; et al.
Journal of Nuclear Science and Technology, 45(6), p.481 - 486, 2008/06
Times Cited Count：5 Percentile：35.07(Nuclear Science & Technology)The intensities of the prompt rays from the N(n,)N reaction have been precisely measured. As the samples, a liquid nitrogen target and a deuterated melamine (C
D
N) were used. The previous values widely used as intensity standards agreed with those obtained in this study within 4-5% in the 2-11 MeV region, however, showed a monotonous decrease with the increase of -ray energy.
Miyazaki, Itaru*; Shimizu, Toshiaki*; Shibata, Michihiro*; Kawade, Kiyoshi*; Furutaka, Kazuyoshi; Nakamura, Shoji; Sakane, Hitoshi
JNC TY8400 2005-002, 40 Pages, 2005/06
JNC-TY8400-2005-002.pdf:2.69MB
Accurate cross section data for the neutron capture of long-lived fission products (LLFP) are needed for developing a nuclear transmutation technology which reduces radioactive wastes by transmuting nuclides that have half-lives of as long as a few million years to other nuclides that have much shorter half-lives. There are some nuclides, whose cross sections cannot be measured in activation method. Utilization of prompt gamma-rays is expected to solve this problem. The aim of present study was twofold: (i) to measure emission probabilities of the high energy gamma-ray, up to 10MeV, emitted fromN(n, gamma)N reaction, which are usually used as standards, in order to improve their accuracies and (ii) to develop a measurement method for neutron capture cross sections by using prompt gamma-rays. Emission probabilities of principal prompt gamma-rays fromN(n, gamma)N reaction were determined with 0.2-0.9% errors. For ten nuclides,
Na,
Al,
55 Mn,
Ni,
Cu,
Pr,
W, and
capture cross sections were measured by using prompt gamma-rays and gamma-rays following b-decay. By comparing both cross section values, it was found that emission probabilities of prompt gamma-rays reported in the literatures were systematically larger than those inferred from the cross sections that were determined in activation methods. The cross section of a
Pd (n, gamma)
Pd reaction at thermal energy was measured. Considering transmutation of the nuclide, the cross section ofPd(n, gamma), which is an isotope of palladium, is also necessary. A lower limit of the cross section was determined with 6% accuracy. Additionally, a method of estimating an upper limit was examined by noting similarity of nuclear structures to the neighboring nuclides. It was estimated that the observed lower limit of emission probabilities correspond to 79% of the cross section.
Maekawa, Kazuhiko*; Yoshimura, Tadahiro*; Kikuchi, Toshiaki*; Hoshino, Yasushi*; Munekata, Hideki*; Shimizu, Makoto*
JNC TJ9420 2005-004, 284 Pages, 2005/02
JNC-TJ9420-2005-004.pdf:11.56MB
In feasibility studies on commercialized FBR cycle system, comprehensive system investigation and properties evaluation for candidate FBR cycle systems have been implemented through view point of safety, economics, environmental burden reduction, non-proliferation resistivity, etc. As part of these studies, an investigation of small scale sphere-pac fuel fabrication plant with external gelation process was conducted. Until last fiscal year, equipment layout in cells and overall layout design of the 200t-HM/y scale fuel fabrication plant were conducted as well as schematical design studies on main equipments in gelation and reagent recovery processes of the plant. System property data concerning economics and environmental burden reduction of fuel fabrication plant was also acquired. In this fiscal year, the processes from vibropacking to fuel assemblies storage were added to the investigation range, and a conceptual design of whole fuel fabrication plant was studied as well as deepening the design study on main equipments. The conceptual design study was mainly conducted for small 50t-HM/y scale plant and a revising investigation was done for 200t-HM/y scale Plant. Taking the planed comparative evaluation with pellet fuel fabrication system into account, design of equipments which should be equivalent with pellet system, especially in post-vibropacking processes, were standardized in each system. Based on these design studies, system properties data concerning economics and environmental burden reduction of the plant was also acquired. In comparison with existing design, the cell height was lowered on condition that plug type pneumatic system was adopted and fuel fabrication building was downsized by applying rationalized layout design of pellet system to post-vibropacking processes. Reduction of reagent usage at gelation process and rationalization of sintering and O/M controlling processes etc., are foremost tasks.
Nakamura, Hiroo; Riccardi, B.*; Loginov, N.*; Ara, Kuniaki*; Burgazzi, L.*; Cevolani, S.*; Dell'Ocro, G.*; Fazio, C.*; Giusti, D.*; Horiike, Hiroshi*; et al.
Journal of Nuclear Materials, 329-333(1), p.202 - 207, 2004/08
Times Cited Count：14 Percentile：66.09(Materials Science, Multidisciplinary)International Fusion Materials Irradiation Facility (IFMIF), being developed by EU, JA, RF and US, is a deuteron-lithium (Li) reaction neutron source for fusion materials testing. In the end of 2002, 3 year Key Element technology Phase (KEP) to reduce the key technology risk factors has been completed. This paper describes these KEP tasks results. To evaluate Li flow characteristics, a water and Li flow experiments have been done. To develop Li purification system, evaluation of nitrogen and tritium gettering materials have been done. Conceptual design of remote handling and basic experiment have been donde. In addition, safety analysis and diganostics design have been done. In the presentation, the latest design and future prospects will be also summarized.
