Vu, TheDang; Shishido, Hiroaki*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; Miyajima, Shigeyuki*; et al.
Nuclear Instruments and Methods in Physics Research A, 1006, p.165411_1 - 165411_8, 2021/08
Sakakibara, Hiroshi; Aoki, Nobuhiro; Muto, Masahiro; Otabe, Jun; Takahashi, Kenji*; Fujita, Naoyuki*; Hiyama, Kazuhiko*; Suzuki, Hirokazu*; Kamogawa, Toshiyuki*; Yokosuka, Toru*; et al.
JAEA-Technology 2020-020, 73 Pages, 2021/03
The decommissioning is currently in progress at the prototype fast breeder reactor Monju. Fuel assemblies will be taken out of its core for the first step of the great task. Fuel assemblies stand on their own spike plugged into a socket on the core support plate and support with adjacent assemblies through their housing pads each other, resulting in steady core structure. For this reason, some substitutive assemblies are necessary for the purpose of discharging the fuel assemblies of the core. Monju side commissioned, therefore, Plutonium Fuel Development Center to manufacture the substitutive assemblies and the Center accepted it. This report gives descriptions of design, manufacture, and shipment in regard to the substitutive assemblies.
Vu, TheDang; Shishido, Hiroaki*; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Miyajima, Shigeyuki*; Oku, Takayuki; Soyama, Kazuhiko; Aizawa, Kazuya; et al.
Superconductor Science and Technology, 34(1), p.015010_1 - 015010_10, 2021/01
Sheikh, M. A. R.*; Liu, X.*; Matsumoto, Tatsuya*; Morita, Koji*; Guo, L.*; Suzuki, Toru*; Kamiyama, Kenji
Energies (Internet), 13(19), p.5018_1 - 5018_15, 2020/10
Okudaira, Takuya; Oku, Takayuki; Ino, Takashi*; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Takahashi, Shingo*; Aizawa, Kazuya; Endo, Hitoshi*; et al.
Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10
Suzuki, Kenji*; Shiro, Ayumi*; Toyokawa, Hidenori*; Saji, Choji*; Shobu, Takahisa
Quantum Beam Science (Internet), 4(3), p.25_1 - 25_14, 2020/09
It is difficult to evaluate stress by the strain scanning method using a conventional diffractometer and a point detector since the two-dimensional diffraction pattern of a material composed of coarse grains does not have a ring but a spotty. To solve this problem, we proposed a double exposure method using a two-dimensional detector and monochromatized X-rays. In this study, we have developed a technique to apply that technique to white X-rays. The diffraction obtained by irradiating white X-rays for a material with of coarse grains becomes a Laue spot. Therefore, we have carried out developing a CdTe pixel two-dimensional detector that can limit the energy to be detected, and we evaluated the stress using that detector. As a result, we succeeded to measure the strain distribution of a bending specimen made to austenitic stainless steel. In the future, we would like to improve this technology and apply it to actual machine materials.
Tsutsui, Nao; Ban, Yasutoshi; Suzuki, Hideya*; Nakase, Masahiko*; Ito, Sayumi*; Inaba, Yusuke*; Matsumura, Tatsuro; Takeshita, Kenji*
Analytical Sciences, 36(2), p.241 - 246, 2020/02
To investigate the effective separation of actinides (Ans) from lanthanides (Lns), single-stage batch extraction experiments were performed with a novel extractant, tetradodecyl-1,10-phenanthroline-2,9-diamide (TDdPTDA) with various diluents such as 3-nitrobenzotrifluoride (F-3), nitrobenzene, and -dodecane for Am, Cm, and Lns. The extraction kinetics with TDdPTDA was rapid enough to perform the actual extraction flow sheet. The slopes of the distribution ratio versus TDdPTDA concentration and the distribution ratio versus nitric acid concentration were similar for F-3 and nitrobenzene systems but different from -dodecane system. These differences were attributed to the characteristics of the diluents. This study reveals high distribution ratios of Am ( ) and Cm ( ) for TDdPTDA, with the high separation factors (s) of Am from Lns enough for their separation.
Suzuki, Kenji*; Shobu, Takahisa; Shiro, Ayumi*
Zairyo, 68(4), p.312 - 317, 2019/04
Materials after thermal processing such as welding often have coarse grains. To understand the residual stress after processing is very important from the viewpoint of the soundness of the structure. In this study, we proposed a double exposure method that combines a two-dimensional detector and high-energy synchrotron radiation as an X-ray stress measurement method for materials with coarse grains, and confirmed its practicality. As a result of measuring the residual stress of the plastic bending specimen and the indentation specimen of the aluminum alloy (A5052), the effectiveness of this measurement method was clarified because the residual stress distribution was in good agreement with the finite element analysis.
Suzuki, Kenji*; Shobu, Takahisa
E-Journal of Advanced Maintenance (Internet), 10(4), p.9 - 17, 2019/02
In materials with an elastic anisotropy, a stress difference is generated between crystals when plastic deformation occurs, and it is known that this is deeply involved in material fracture. In this study, the residual stress for load direction in the plastically deformed material was investigated for each crystal orientation using the high-energy synchrotron radiation diffraction method. As a result, it was found that the residual stress is a tensile residual stress at an index with a high X-ray elastic constant (Young's modulus obtained for each diffraction surface) and a compressive residual stress at an index with a low X-ray elastic constant. We believe that this result will be useful for the technique of controlling the crystal orientation like the texture as improving the material strength.
Ekawa, Hiroyuki; Ashikaga, Sakiko; Hasegawa, Shoichi; Hashimoto, Tadashi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji*; Nanamura, Takuya; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.021D02_1 - 021D02_11, 2019/02
Ikeuchi, Kazuhiko*; Nakajima, Kenji; Kawamura, Seiko; Kajimoto, Ryoichi; Wakimoto, Shuichi; Suzuki, Kensuke*; Fujita, Masaki*
AIP Advances (Internet), 8(10), p.101318_1 - 101318_5, 2018/10
By means of inelastic neutron scattering, we measured magnetic excitations in a sizable single crystal of LaSrCuAlO, which is an Al-substituted system of the heavily hole-doped cuprate system LaSrCuO with an effective concentration of holes of = 0.25.
Nakayoshi, Akira; Suzuki, Seiya; Okamura, Nobuo; Watanabe, Masayuki; Koizumi, Kenji
Journal of Nuclear Science and Technology, 55(10), p.1119 - 1129, 2018/10
Asano, Shun*; Ishii, Kenji*; Matsumura, Daiju; Tsuji, Takuya; Ina, Toshiaki*; Suzuki, Kensuke*; Fujita, Masaki*
Journal of the Physical Society of Japan, 87(9), p.094710_1 - 094710_5, 2018/09
Sheikh, Md. A. R.*; Son, E.*; Kamiyama, Motoki*; Morioka, Toru*; Matsumoto, Tatsuya*; Morita, Koji*; Matsuba, Kenichi; Kamiyama, Kenji; Suzuki, Toru*
Journal of Nuclear Science and Technology, 55(6), p.623 - 633, 2018/06
During core-disruptive accidents in sodium-cooled fast reactors, the sedimentation behavior of fragmented debris is crucial for in-vessel retention. The height of the beds formed may influence both the cooling of the bed and the neutronic characteristics. To develop an experimental database of bed formation behavior, a series of experiments using simulant materials, namely, AlO, ZrO, and stainless steel, were performed under gravity-driven discharge of solid particles from a nozzle into a quiescent cylindrical water pool. The bed height was measured for particles of different size, density, and sphericity, and an injection nozzle with varying diameter, injection velocity, and injection height. From these experiments, an empirical correlation was established to predict the bed height for both homogeneous and mixed particles for the different properties. This correlation reproduces reasonably well the experimental trend in bed height.
Araki, Kenji*; Suzuki, Kei*; Gubler, P.; Oka, Makoto
Physics Letters B, 780, p.48 - 53, 2018/05
Charmonium spectral functions in vector and pseudoscalar channels at finite temperature are investigated through the complex Borel sum rules and the maximum entropy method. Our approach enables us to extract the peaks corresponding to the excited charmonia, as well as those of the ground states, which has never been achieved in usual QCD sum rule analyses. We show the spectral functions in vacuum and their thermal modification around the critical temperature, which leads to the almost simultaneous melting (or peak disappearance) of the ground and excited states.
Suzuki, Hiroshi; Kusunoki, Koichi*; Satake, Kosuke*; Kanematsu, Manabu*; Koyama, Taku*; Niwa, Akinobu*; Kabayama, Kenji*; Mukai, Tomohisa*; Kawasaki, Takuro; Harjo, S.
Hihakai Kensa, 67(4), p.180 - 186, 2018/04
The bond behavior between rebar and concrete under bending moment was investigated by measuring the stress distribution in the two-dimensionally distributed rebars embedded in the reinforced concrete (RC) beam using neutron diffraction. The stress distributions in both of the main rebar and the transverse stirrups embedded in concrete were successfully measured at the fixed measurement configuration without any sample rotations, by suggesting a simple measurement technique on the premise that the transverse restriction from the surrounding concrete to the main rebar is negligible. The bending and shear fracture behavior of the RC beam specimen was predicted by comparing changes in the stress distribution in the rebars measured by neutron diffraction with respect to the applied stress, with the macroscopic deformation measured by strain gauges fixed on the concrete surface. In this study, it was found that the neutron diffraction technique can be a useful technique to evaluate not only the anchorage performance but also the bending behavior of the RC beam.
Asano, Shun*; Suzuki, Kensuke*; Matsumura, Daiju; Ishii, Kenji*; Ina, Toshiaki*; Fujita, Masaki*
Journal of Physics; Conference Series, 969, p.012051_1 - 012051_5, 2018/04
Kobata, Masaaki; Okane, Tetsuo; Nakajima, Kunihisa; Suzuki, Eriko; Owada, Kenji; Kobayashi, Keisuke*; Yamagami, Hiroshi; Osaka, Masahiko
Journal of Nuclear Materials, 498, p.387 - 394, 2018/01
In this study, for the understandings of Cesium (Cs) adsorption behavior on structure materials in severe accidents at a light water nuclear reactor, the chemical state of Cs and its distribution on the surface of SUS304 stainless steel (SS) with different Si concentration were investigated by hard X-ray photoelectron spectroscopy (HAXPES) and scanning electron microscope / energy dispersive X-ray spectroscopy (SEM/EDX). As a result, it was found that Cs is selectively adsorbed at the site where Si distributes with high concentration. CsFeSiO is a dominant Cs products in the case of low Si content, mainly formed, while CsSiO and CsSiO are formed in addition to CsFeSiO in the case of high Si content. The chemical forms of the Cs compounds produced in the adsorption process on the SS surface has a close correlation with the concentration and chemical states of Si originally included in SS.
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Hirayama, Hideo*; Kondo, Kenjiro*; Suzuki, Seishiro*; Tanimura, Yoshihiko; Iwanaga, Kohei*; Nagata, Hiroshi*
EPJ Web of Conferences, 153, p.08010_1 - 08010_3, 2017/09
Pulse height distributions were measured using a CdZnTe detector inside a lead collimator to investigate main source producing high dose rates above the shield plugs of Unit 3 at Fukushima Daiichi Nuclear Power Station. It was confirmed that low energy photons are dominant. Concentrations of Cs-137 under 60 cm concrete of the shield plug were estimated to be between 8.110 and 5.710 Bq/cm from the measured peak count rate of 0.662 MeV photons. If Cs-137 was distributed on the surfaces of the gaps of the shied plugs with radius 6 m and with the averaged concentration of 5 points, 2.610 Bq/cm, total amount of Cs-137 is estimated to be 30 PBq.