Nakamura, Shota*; Hyodo, Kazushi*; Matsumoto, Yuji*; Haga, Yoshinori; Sato, Hitoshi*; Ueda, Shigenori*; Mimura, Kojiro*; Saiki, Katsuyoshi*; Iso, Kosei*; Yamashita, Minoru*; et al.
Journal of the Physical Society of Japan, 89(2), p.024705_1 - 024705_5, 2020/02
Sato, Shigeo*; Kuroda, Asumi*; Sato, Kozue*; Kumagai, Masayoshi*; Harjo, S.; Tomota, Yo*; Saito, Yoichi*; Todoroki, Hidekazu*; Onuki, Yusuke*; Suzuki, Shigeru*
Tetsu To Hagane, 104(4), p.201 - 207, 2018/00
Tomota, Yo*; Sato, Shigeo*; Uchida, M.*; Xu, P. G.; Harjo, S.; Gong, W.; Kawasaki, Takuro
Materials Science Forum, 905, p.25 - 30, 2017/08
Tomota, Yo*; Sato, Shigeo*; Harjo, S.
Tetsu To Hagane, 103(2), p.73 - 85, 2017/01
Onuki, Yusuke*; Hoshikawa, Akinori*; Sato, Shigeo*; Xu, P. G.; Ishigaki, Toru*; Saito, Yoichi*; Todoroki, Hidekazu*; Hayashi, Makoto*
Journal of Applied Crystallography, 49(5), p.1579 - 1584, 2016/10
Sato, Shigeo*; Onuki, Yusuke*; Shobu, Takahisa; Shiro, Ayumi*; Tashiro, Hitoshi*; Todoroki, Hidekazu*; Suzuki, Shigeru*
Kinzoku, 86(8), p.654 - 660, 2016/08
no abstracts in English
Suzuki, Hiroshi; Yamada, Rui*; Tsubaki, Shinki*; Imafuku, Muneyuki*; Sato, Shigeo*; Watanuki, Tetsu; Machida, Akihiko; Saida, Junji*
Metals, 6(1), p.12_1 - 12_11, 2016/01
Elastic deformation behaviors of as-cast and annealed eutectic and hypoeutectic Zr-Cu-Al bulk metallic glasses (BMGs) were investigated on a basis of different strain-scales determined by X-ray scattering and the strain gauge. The microscopic strains determined by Direct-space method (DSM) and Q-space method (QSM) were compared with the macroscopic strain measured by the strain gauge, and the difference in the deformation mechanism between eutectic and hypoeutectic Zr-Cu-Al BMGs was investigated by their correlation. The eutectic ZrCuAl BMG obtains more homogeneous microstructure by free-volume annihilation after annealing, improving a resistance to deformation but degrading ductility because of a decrease in the volume fraction of WBRs (Weakly-Bonded Regions) with relatively high mobility. On the other hand, the as-cast hypoeutectic ZrCuAl BMG originally has homogeneous microstructure, but loses its structural and elastic homogeneities because of nanocluster formation after annealing. Such structural changes after annealing might develop unique mechanical properties showing no degradations of ductility and toughness for the structural-relaxed hypoeutectic BMGs.
Kinuhata, Hiroshi*; Yamamoto, Masahiko; Taguchi, Shigeo; Surugaya, Naoki; Sato, Soichi; Kodama, Takashi*; Tamauchi, Yoshikazu*; Shibata, Yuki*; Anzai, Kiyoshi*; Matsuoka, Shingo*
Nuclear Technology, 192(2), p.155 - 159, 2015/11
Experiments using a small-scale apparatus with 30 ml actual high-level liquid waste from the Tokai Reprocessing Plant were carried out to show that the hydrogen concentration in the gas phase reaches a steady-state value of much less than 4% (lower explosive limit) in the absence of sweeping-air. The H concentration reached a steady-state value as was expected and it was compared with a value predicted from an equation with parameters which had been obtained using the simulated solution. Satisfactory agreement showed that the Pd-ion catalytic H consumption reaction previously found in the simulated solution proceeded equally well in the actual solution.
Yamamoto, Masahiko; Surugaya, Naoki; Mori, Eito; Taguchi, Shigeo; Sato, Soichi
JAEA-Research 2015-013, 27 Pages, 2015/10
The H concentration generating from Highly Active Liquid Waste (HALW) of Tokai Reprocessing Plant is measured in a closed experimental system. The experimental results show that H concentration gradually increases at first and then approaches a steady-state due to the H consumption reaction by Pd ions. The highest H concentration is 1200 ppm (0.1%) when the solution temperature is at 23C. It is found that H generating from HALW is equilibrated one order of magnitude lower than the H combustion lower limit. Moreover, a model based on H generation from HALW by the radiolysis and H consumption reaction by Pd ions is proposed and applied to evaluate H concentration behavior in the gas phase. The calculated H concentrations from proposed model agreed well with the experimental values. It is demonstrated that the behavior of H generating from HALW can be evaluated quantitatively by applying the proposed model in this study.
Sato, Shigeo*; Shobu, Takahisa; Sato, Kozue*; Ogawa, Hiromi*; Wagatsuma, Kazuaki*; Kumagai, Masayoshi*; Imafuku, Muneyuki*; Tashiro, Hitoshi*; Suzuki, Shigeru*
ISIJ International, 55(7), p.1432 - 1438, 2015/07
To characterize the distribution and anisotropy of dislocations in cold-drawn pearlitic steel wires, X-ray diffraction line-profile analysis was performed using synchrotron radiation micro-beams. The plastic shear strain was generally more severe near the surface than the center of the wire, whereas the dislocation density distribution was almost constant from the center to the surface. On the other hand, the dislocation rearrangement, which evolves the dislocation cell structure, progressed closer to the surface. It was also revealed that a difference between the hardness in axial and transverse wire directions could be explained by anisotropic dislocation density. Line-profile analysis based on diffraction data at elevated temperatures was performed. Whereas the cementite recovery progressed at a constant rate, the ferrite phase recovery rate was temperature-dependent, suggesting that the ferrite phase recovery was less related to that of the cementite phase.
Yamamoto, Masahiko; Taguchi, Shigeo; Sato, Soichi; Surugaya, Naoki
Journal of Separation Science, 38(10), p.1807 - 1812, 2015/05
The extraction of Pu with tri--butyl phosphate (TBP) is performed using a glass microchip to evaluate the extraction rate. The parallel two-phase laminar flow is constructed in a microchannel by introducing plutonium nitrate solution and TBP diluted with -dodecane as aqueous and organic phase, respectively. It was found that extraction ratio of Pu increases with increasing the contact time of two phases. A numerical model based on the diffusion in the microchannel and the reaction at the interface was incorporated to evaluate the extraction rate. The experimental data points were subjected to least-squares fitting and the forward extraction rate of Pu(IV) was determined.
Sato, Takeshi; Muto, Shigeo; Akiyama, Kiyomitsu; Aoki, Kazufumi; Okamoto, Akiko; Kawakami, Takeshi; Kume, Nobuhide; Nakanishi, Chika; Koie, Masahiro; Kawamata, Hiroyuki; et al.
JAEA-Review 2014-048, 69 Pages, 2015/02
JAEA was assigned as a designated public institution under the Disaster Countermeasures Basic Act and under the Armed Attack Situations Response Act. Based on these Acts, the JAEA has the responsibility of providing technical support to the national government and/or local governments in case of disaster responses or response in the event of a military attack, etc. In order to fulfill the tasks, the JAEA has established the Emergency Action Plan and the Civil Protection Action Plan. In case of a nuclear emergency, NEAT dispatches specialists of JAEA, supplies the national government and local governments with emergency equipment and materials, and gives technical advice and information. In normal time, NEAT provides various exercises and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response institutions of the national and local governments, police, fire fighters, self-defense forces, etc. in addition to the JAEA itself. The NEAT also researches nuclear disaster preparedness and response, and cooperates with international organizations. In the FY2013, the NEAT accomplished the following tasks: (1) Technical support activities as a designated public institution in cooperation with the national and local governments, etc. (2) Human resource development, exercise and training of nuclear emergency response personnel for the national and local governments, etc. (3) Researches on nuclear disaster preparedness and response, and sending useful information (4) International contributions to Asian countries on nuclear disaster preparedness and response in collaboration with the international organizations
Mori, Eito; Yamamoto, Masahiko; Taguchi, Shigeo; Sato, Soichi; Kitao, Takahiko; Surugaya, Naoki
Nippon Hozen Gakkai Dai-11-Kai Gakujutsu Koenkai Yoshishu, p.132 - 138, 2014/07
The contamination of the radioactive material was observed on the filter casing surface of the glove box installed at the analytical laboratory in Tokai Reprocessing Plant. The cause of the contamination was investigated with visual inspection, penetrant testing and ultrasonic thickness measurement. It was found that a micro through-hole due to the corrosion of stainless-steel was generated in the glove box filter casing. The repair work of the filter casing was performed keeping the glove box negative pressure. The corrosion part of filter casing was replaced and newly fabricated casing was connected to the glove box with Tungsten Inert Gas welding method.
Sato, Takeshi; Muto, Shigeo; Okuno, Hiroshi; Katagiri, Hiromi; Akiyama, Kiyomitsu; Okamoto, Akiko; Koie, Masahiro; Ikeda, Takeshi; Nemotochi, Toshimasa; Saito, Toru; et al.
JAEA-Review 2013-046, 65 Pages, 2014/02
When a nuclear emergency occurs in Japan, the Japan Atomic Energy Agency (JAEA) has the responsibility of providing technical support to the National government, local governments, police, fire stations and nuclear operators etc., because the JAEA has been designated as the Designated Public Institution under the Basic Act on Disaster Control Measures and the Act on Response to Armed Attack Situations, etc.. The Nuclear Emergency Assistance and Training Center (NEAT) of JAEA provides a comprehensive range of technical support activities to an Off-Site Center in case of a nuclear emergency. Specifically, NEAT gives technical advice and information, dispatches specialists as required, and supplies the National Government and local governments with emergency equipments and materials. NEAT provides various exercise and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response organizations at normal times. The tasks of NEAT, with its past experiences as a designated public institution including the responses to TEPCO's Fukushima Accident, have been shifted to technical supports to the national government for strengthening its abilities to emergency responses; the NEAT therefore focused on maintenance and operation of its functions, and strengthening its response abilities in cooperation with the national government. This annual report summarized these activities of JAEA/NEAT in the fiscal year 2012.
Yashiro, Shigeo; Aoki, Kazuhisa; Sato, Tomohiko; Tanji, Kazuhiro
JAEA-Review 2013-038, 123 Pages, 2014/01
With the rapid progress of the utilization of Information Technology (IT), IT infrastructure (network environment and information system) became crucial as a lifeline for promoting business. At the same time, changes in the circumstances surrounding the IT infrastructure globalize the threat of cyber attacks and increase the risk of the information security such as unlawful access to an information system, viral infection, an alteration of a website, disclosure of subtlety information, destruction of an information system and so on. Information security measure is an important issue in Japan Atomic Energy Agency (JAEA). In order to protect the information property of JAEA from the threat, Center for Computational Science & e-Systems (CCSE) has been taking triadic measures for information security: (1) to lay down a set of information security rules, (2) to introduce security equipments to backbone network and (3) to provide information security education. This report is a summary of the contents of the information security education by e-learning.
Nakanishi, Chika; Sato, Takeshi; Sato, Sohei; Nagai, Haruyasu; Kakefuda, Toyokazu; Katata, Genki; Tsuzuki, Katsunori; Ikeda, Takeshi; Okuno, Hiroshi; Yamamoto, Kazuya; et al.
JAEA-Technology 2013-030, 105 Pages, 2013/10
North Korea carried out the third nuclear test in February 2013. Due to the request of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Nuclear Emergency Assistance and Training Center (NEAT) and Nuclear Science and Engineering Directorate (NSED) of JAEA predicted the atmospheric dispersion of radionuclide by WSPEEDI-II for the purpose of contributing to the environmental monitoring plan. From February 12 to 22, they provided daily reports on the prediction to the MEXT and the Ministry of Defense. MEXT has published these reports on the website. Since April 2012, NEAT and NSED had prepared to predict by the framework for the prediction around the clock during 10months until February 2013. This report described this experience and pointed issues out on this system.
Suzuki, Hiroshi; Saida, Junji*; Shobu, Takahisa; Katsuyama, Jinya; Kato, Hidemi*; Imafuku, Muneyuki*; Sato, Shigeo*
Scripta Materialia, 66(10), p.801 - 804, 2012/05
Compressive deformation mechanism of a ZrAlNiCu bulk metallic glass containing 10vol.%ZrC (ZrC-BMG) was evaluated by measuring the residual strains in the compressive deformed samples using the synchrotron X-ray diffraction and also evaluating the localized deformation behavior around the ZrC particles by the finite element analysis. Phase stress shared by the metallic glass matrix was increased before macroscopic yielding due to local plastic deformation around the ZrC particles. After macroscopic yielding, the phase stress shared by the ZrC phase was drastically increased, and finally the ZrC-BMG was fractured by breaking the ZrC particles reaching its fracture strength.
Yamamoto, Masahiro; Kato, Chiaki; Sato, Tomonori; Nakano, Junichi; Ugachi, Hirokazu; Tsukada, Takashi; Kaji, Yoshiyuki; Tsujikawa, Shigeo*; Hattori, Shigeo*; Yoshii, Tsuguyasu*; et al.
JAEA-Review 2012-007, 404 Pages, 2012/03
There are many LWRs which have been operated for more than 20 years in Japan and it is expected that technique corresponding to aging plants are necessary established for safety operation in LWRs. A lot of troubles related to SCC are reported and many investigations are concerned with SCC mechanism and technical evaluation. In this paper, those research data were collected as possible widely and reviewed systematically. Current circumstances concerned with SCC in LWRs were reviewed specifically as follows: SCC incidents, SCC evaluation methods for crack initiation and propagation, the investigations concerned with SCC mechanism and monitoring technique for corrosive environment. Influences with reactor types (BWR, PWR), materials (stainless steels, Ni alloys) and SCC evaluating methods (laboratories and actual plants) were summarized as graphs and tables easy to understand in common/difference points concerned with SCC. From these arranged results, future themes were considered and remarked SCC phenomenon was summarized in actual plants. As for SCC evaluations under the accelerate conditions in the laboratory test, it was suggested that a computational prediction and modeling including statistical technique and microscopic analysis in crack initiation were important. Furthermore it was suggested that monitoring techniques predicting SCC initiation and grasping plant circumstance in operation and feasibility in actual plants were important.
Sato, Sohei; Yamamoto, Kazuya; Muto, Shigeo; Fukumoto, Masahiro; Katagiri, Hiromi
JAEA-Review 2011-049, 77 Pages, 2012/01
The Tohoku District-off the Pacific Ocean Earthquake occurred at 14:46 on March 11, 2011. Tsunami caused by the earthquake attacked the Fukushima Dai-ichi and Fukushima Dai-ni Nuclear Power Stations of Tokyo Electric Power Company and nuclear accidents involving release of radioactive material occurred. Since the earthquake, Nuclear Emergency Assistance and Training Center (NEAT) has served as a base of support activities conducted by Japan Atomic Energy Agency (JAEA). After nearly half a year has passed since the occurrence of the accident, we compiled the support activities of NEAT. NEAT's lessons learned and recommendations based on the experiences of support activities to the accident should be very helpful in considering the structure of nuclear emergency preparedness and response. We summarized them in this time. We hope that this report helps further developing nuclear emergency preparedness and response in the future.
Sakurai, Eiko*; Yanai, Kazuhiko*; Ishii, Keizo*; Fujiki, Kota*; Hiraishi, Shingo*; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Okamura, Nobuyuki*; Yokoyama, Akihito; Kada, Wataru; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 84, 2012/01