Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 1256

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Application of energy-resolving neutron imaging to major-component analyses of materials using four-channel superconducting detector

Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Soyama, Kazuhiko; Koyama, Tomio*; et al.

IEEJ Transactions on Electrical and Electronic Engineering, 19(11), p.1888 - 1894, 2024/11

 Times Cited Count:0 Percentile:0.00(Engineering, Electrical & Electronic)

JAEA Reports

SIMMER-III and SIMMER-IV; Computer codes for LMFR core disruptive accident analysis

Kondo, Satoru; Tobita, Yoshiharu*; Morita, Koji*; Kamiyama, Kenji; Yamano, Hidemasa; Suzuki, Toru*; Tagami, Hirotaka; Sogabe, Joji; Ishida, Shinya

JAEA-Research 2024-008, 235 Pages, 2024/10

JAEA-Research-2024-008.pdf:4.77MB

The SIMMER-III and SIMMER-IV computer codes, developed at the Japan Atomic Energy Agency are the codes with two- and three-dimensional, multi-field, multi-component fluid-dynamics models, coupled with a space- and time-dependent neutron kinetics model. The codes have been used widely for simulating complex phenomena during core-disruptive accidents in liquid-metal fast reactors. Advanced features of the codes in comparison with the former codes include: stable and robust fluid-dynamics algorithm with up to 8 velocity fields, improved representation of structures and multi-phase flow topology, comprehensive treatment of complex heat and mass transfer processes, accurate analytic equations of state, a stable and efficient neutron flux shape solution method and decay heat model. This report describes the models and methods of SIMMER-III and SIMMER-IV. For those individual models, the details of which have been reported elsewhere, only the outlines of the models are presented. The reports of code verification and validation have been already published.

Journal Articles

X-ray magnetic circular dichroism study of ferromagnetic 5$$d$$ $$j_{eff}=3/2$$ insulator Sr$$_3$$OsO$$_6$$

Wakabayashi, Yuki*; Krockenberger, Y.*; Yamagami, Kohei*; Wadachi, Hiroki*; Shibata, Goro; Fujimori, Atsushi*; Kawamura, Naomi*; Suzuki, Motohiro*; Taniyasu, Yoshitaka*; Yamamoto, Hideki*

SPring-8/SACLA Riyo Kenkyu Seikashu (Internet), 12(5), p.291 - 293, 2024/10

no abstracts in English

Journal Articles

Continuous structural phase transition and antiferromagnetic order in ilmenite-type NiVO$$_{3}$$

Yamamoto, Hajime*; Ikeda, Osamu*; Honda, Takashi*; Kimura, Kenta*; Aoyama, Takuya*; Ogushi, Kenya*; Suzuki, Akio*; Ishii, Kenji*; Matsumura, Daiju; Tsuji, Takuya; et al.

Physical Review Materials (Internet), 8(9), p.094402_1 - 094402_6, 2024/09

 Times Cited Count:2 Percentile:77.00(Materials Science, Multidisciplinary)

Journal Articles

R&D status of digital technology on inverse estimation of radioactive source distributions and related source countermeasures; Fast Digital Twin Tech. in Decommissioning Field: 3D-ADRES-Indoor FrontEnd

Machida, Masahiko; Yamada, Susumu; Kim, M.; Tanaka, Satoshi*; Tobita, Yasuhiro*; Iwata, Ayako*; Aoki, Yuto; Aoki, Kazuhisa; Yanagisawa, Kenichi*; Yamaguchi, Takashi; et al.

RIST News, (70), p.3 - 22, 2024/09

Inside the Fukushima Daiichi Nuclear Power Plant (1F), there are many locations with high radiation levels due to contamination by radioactive materials that leaked from the reactor. These pose a significant obstacle to the smooth progress of decommissioning work. To help solve this issue, the Japan Atomic Energy Agency (JAEA), under a subsidy from the Ministry of Economy, Trade, and Industry's decommissioning and contaminated water management project, is conducting research and development on digital technologies to improve the radiation environment inside the decommissioning site. This project, titled "Development of Technology to Improve the Environment Inside Reactor Buildings (Enhancing Digital Technology for Environment and Source Distribution to Reduce Radiation Exposure)," began in April of FY 2023. In this project, the aim is to develop three interconnected systems: FrontEnd, Pro, and BackEnd. The FrontEnd system, based on the previously developed 3D-ADRES-Indoor (prototype) from FY 2021-2022, will be upgraded to a high-speed digital twin technology usable on-site. The Pro system will carry out detailed analysis in rooms such as the new office building at 1F, while the BackEnd system will serve as a database to centrally manage the collected and analyzed data. This report focuses on the FrontEnd system, which will be used on-site. After point cloud measurement, the system will quickly create a 3D mesh model, estimate the radiation source from dose rate measurements, and refine the position and intensity of the estimated source using recalculation techniques (re-observation instructions and re-estimation). The results of verification tests conducted on Unit 5 are also presented. Furthermore, the report briefly discusses the future research and development plans for this project.

Journal Articles

Earthquake resistance by improvement construction for ground around High Active liquid Waste facility in Tokai Reprocessing Plant

Yokochi, Masaru; Sasaki, Shunichi; Yanagibashi, Futoshi; Asada, Naoki; Komori, Tsuyoshi; Fujieda, Sadao; Suzuki, Hisanori; Takeuchi, Kenji; Uchida, Naoki

Nihon Hozen Gakkai Dai-20-Kai Gakujutsu Koenkai Yoshishu, p.1 - 4, 2024/08

Tokai Reprocessing Plant, which is shifted to decommissioning stage, stores large amount of high-level radioactive liquid waste (HLLW) generated by reprocessing of spent nuclear fuels in High-level Active Waste facility (HAW). Radioactive risk related to HLLW has been concentrated in HAW until the completion of vitrification. Natural disasters such as earthquake may damage cooling function of HAW. Therefore, HAW must improve earthquake resistance, as exchanging the ground around HAW facility and pipe trench by concrete. This earthquake resistance construction starts from July of 2020 and completed in March 2024. This report summarizes the construction work and describes the inspection results after the construction.

Journal Articles

Ground improvement work for deployment place of accident response equipment at Tokai Reprocessing Plant

Asada, Naoki; Sasaki, Shunichi; Rachi, Reona; Komori, Tsuyoshi; Suzuki, Hisanori; Takeuchi, Kenji; Uchida, Naoki

Nihon Hozen Gakkai Dai-20-Kai Gakujutsu Koenkai Yoshishu, p.5 - 8, 2024/08

no abstracts in English

Journal Articles

Neutron transmission imaging system with a superconducting kinetic inductance detector

Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Soyama, Kazuhiko; Koyama, Tomio*; et al.

Journal of Physics; Conference Series, 2776, p.012009_1 - 012009_9, 2024/06

Journal Articles

Interaction of solute manganese and nickel atoms with dislocation loops in iron-based alloys irradiated with 2.8 MeV Fe ions at 400 $$^{circ}$$C

Nguyen, B. V. C.*; Murakami, Kenta*; Chena, L.*; Phongsakorn, P. T.*; Chen, X.*; Hashimoto, Takashi; Hwang, T.*; Furusawa, Akinori; Suzuki, Tatsuya*

Nuclear Materials and Energy (Internet), 39, p.101639_1 - 101639_9, 2024/06

 Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)

Journal Articles

Sensitive $$^{236}$$U/$$^{238}$$U isotopic analysis of trace uranium in safeguards environmental samples using multicollector inductively coupled plasma mass spectrometry

Tomita, Jumpei; Tomita, Ryohei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka

Journal of the American Society for Mass Spectrometry, 35(6), p.1178 - 1183, 2024/05

 Times Cited Count:0 Percentile:0.00(Biochemical Research Methods)

A sensitive analytical technique was investigated in order to determine 10$$^{-7}$$ order of $$^{236}$$U/$$^{238}$$U ratio in the sub-ng of uranium using a multi-collector ICP-MS. First, the solution volume was concentrated to one tenth to obtain higher intensities. Next, data acquisition was started from the beginning of the solution uptake and continued until all solution was exhausted. Taking advantage of multi-collector measurement, all data were used with excepting the portion affected by air mixing at the beginning and end of sample introduction. The isotope ratios were calculated from the total counts of each isotope. This technique was applied to U isotope standard (IRMM-184) to measure the 10$$^{-7}$$ order of $$^{236}$$U/$$^{238}$$U ratio in the sub-ng of uranium. Measured values were in good agreement with the certified value within the uncertainity ($$k$$=2). The uncertainties obtained with this new technique (32% on average) were revised to be 10 times smaller than those obtained with the conventionalmethod.

Journal Articles

Degradation of a lithium cobalt oxide cathode under high voltage operation at an interface with an oxide solid electrolyte

Ito, Kotaro*; Tamura, Kazuhisa; Shimizu, Keisuke*; Yamada, Norifumi*; Watanabe, Kenta*; Suzuki, Kota*; Kanno, Ryoji*; Hirayama, Masaaki*

RSC Applied Interfaces (Internet), 1(4), p.790 - 799, 2024/04

LiCoO$$_{2}$$ is widely used as a cathode material in lithium-ion batteries. However, the reversible capacity of LiCoO$$_{2}$$ at high voltage is not well known because of the oxidative degradation of the electrolyte. In this study, a thin-film all-solid-state battery was fabricated with epitaxially grown LiCoO$$_{2}$$ cathode and Li$$_{3}$$PO$$_{4}$$ solid electrolyte as a model battery that operates stably at high voltages, ranging up to 4.6 V, without drastic degradation. However, the charge-discharge capacities of the battery decreased with cycling at 4.7 V. ${it In situ}$ synchrotron X-ray diffraction studies revealed that LiCoO$$_{2}$$ was deactivated via a change in its crystal structure to O1 type, with narrow interlayer distances, at 4.7 V. The reduced distance between the interlayers in the O1 structure possibly prevents the re-intercalation of Li ions, leading to irreversibility.

Journal Articles

Stress measurement of stainless steel piping welds by complementary use of high-energy synchrotron X-rays and neutrons

Miura, Yasufumi*; Suzuki, Kenji*; Morooka, Satoshi; Shobu, Takahisa

Quantum Beam Science (Internet), 8(1), p.1_1 - 1_14, 2024/03

Journal Articles

Intercalative and non-intercalative photo-recharge using all-solid-state cells for solar energy conversion and storage

Yoshimoto, Masataka*; Tamura, Kazuhisa; Watanabe, Kenta*; Shimizu, Keisuke*; Horisawa, Yuhei*; Kobayashi, Takeshi*; Tsurita, Hanae*; Suzuki, Kota*; Kanno, Ryoji*; Hirayama, Masaaki*

Sustainable Energy & Fuels (Internet), 8(6), p.1236 - 1244, 2024/03

 Times Cited Count:0 Percentile:0.00(Chemistry, Physical)

Photo-rechargeable systems, which can efficiently convert and store solar energy into chemical energy within single devices, are essential to harness sunlight effectively. Photo-(de)intercalation plays a pivotal role in the functionality of photorechargeable systems. Nevertheless, the photo-(de)intercalation process has not been conclusively confirmed owing to potential interference from side reactions, such as the decomposition of liquid electrolytes and the elution of electrode materials. In this study, we successfully demonstrated photo-responsive Li$$^{+}$$-deintercalation using an all-solid-state thin-film battery comprised of epitaxially-grown anatase TiO$$_{2}$$ doped with Nb (a-TiO$$_{2}$$:Nb) as the cathode. Under light irradiation, Li$$^{+}$$-deintercalation occurred and was subsequently reversibly intercalated into a-TiO$$_{2}$$:Nb during discharge.

Journal Articles

Experimental visualization of water/ice phase distribution at cold start for practical-sized polymer electrolyte fuel cells

Higuchi, Yuki*; Yoshimune, Wataru*; Kato, Satoru*; Hibi, Shogo*; Setoyama, Daigo*; Isegawa, Kazuhisa*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Harada, Masashi*; et al.

Communications Engineering (Internet), 3, p.33_1 - 33_7, 2024/02

Journal Articles

Neutron transmission CB-KID imager using samples placed at room temperature

Ishida, Takekazu*; Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Koyama, Tomio*; et al.

Journal of Low Temperature Physics, 214(3-4), p.152 - 157, 2024/02

 Times Cited Count:0 Percentile:0.00(Physics, Applied)

Journal Articles

Stable photoelectrochemical reactions at solid/solid interfaces toward solar energy conversion and storage

Watanabe, Kenta*; Horisawa, Yuhei*; Yoshimoto, Masataka*; Tamura, Kazuhisa; Suzuki, Kota*; Kanno, Ryoji*; Hirayama, Masaaki*

Nano Letters, 24(6), p.1916 - 1922, 2024/02

 Times Cited Count:3 Percentile:80.53(Chemistry, Multidisciplinary)

Electrochemistry has extended from reactions at solid/liquid interfaces to those at solid/solid interfaces. In this study, we achieve the stable photoelectrochemical reaction at the semiconductor-electrode/solid-electrolyte interface in Nb-doped anatase-TiO$$_{2}$$ (a-TiO$$_{2}$$:Nb)/Li$$_{3}$$PO$$_{4}$$ (LPO)/Li all-solid-state cell. The oxidative currents of a-TiO$$_{2}$$:Nb/LPO/Li increase upon light irradiation when a-TiO$$_{2}$$:Nb is located at a potential that is more positive than its flat-band potential. The photoelectrochemical reaction at the semiconductor/solid-electrolyte interface is driven by the same principle as that at semiconductor/liquid-electrolyte interfaces. Thus, we extend photoelectrochemistry to all-solid-state systems composed of solid/solid interfaces.

Journal Articles

Development of a simulator for operator proficiency training for seafloor exploration by remotely operated vehicle

Kamewari, Ryusei*; Fujishima, Yusuke*; Kawabata, Kuniaki; Suzuki, Kenta; Sakagami, Norimitsu*; Takemura, Fumiaki*; Takahashi, Satoru*

Proceedings of the IUTAM Symposium on Optimal Guidance and Control for Autonomous Systems 2023 (IUTAM Bookseries No.40), p.85 - 101, 2024/01

JAEA Reports

Annual report for FY2021 on the activities of Naraha Center for Remote Control Technology Development (April 1, 2021 - March 31, 2022)

Akiyama, Yoichi; Shibanuma, So; Yanagisawa, Kenichi*; Yamada, Taichi; Suzuki, Kenta; Yoshida, Moeka; Ono, Takahiro; Kawabata, Kuniaki; Watanabe, Kaho; Morimoto, Kyoichi; et al.

JAEA-Review 2023-015, 60 Pages, 2023/09

JAEA-Review-2023-015.pdf:4.78MB

Naraha Center for Remote Control Technology Development (NARREC) was established in Japan Atomic Energy Agency to promote a decommissioning work of Fukushima Daiichi Nuclear Power Station (Fukushima Daiichi NPS). NARREC consists of a Full-scale Mock-up Test Building and Research Management Building. Various test facilities are installed in these buildings for the decommissioning work of Fukushima Daiichi NPS. These test facilities are intended to be used for various users, such as companies engaged in the decommissioning work, research and development institutions, educational institutions and so on. The number of NARREC facility uses was 84 in FY2021. We participated booth exhibitions and presentations on the decommissioning related events. Moreover, we also contributed to the development of human resources by supporting the 6th Creative Robot Contest for Decommissioning. As a new project, "Narahakko Children's Classroom" was implemented for elementary school students in Naraha Town. This report summarizes the activities of NARREC in FY2021, such as the utilization of facilities and equipment of NARREC, the development of remote-control technologies for supporting the decommissioning work, arrangement of the remote-control machines for emergency response, and training for operators by using the machines.

Journal Articles

Development of analytical techniques for isotopic composition determination of uranium particles in environmental sample for safeguards with Secondary Ion Mass Spectrometry

Tomita, Ryohei; Tomita, Jumpei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka

Hosha Kagaku, (48), p.1 - 15, 2023/09

Secondary Ion Mass Spectrometry (SIMS) is the method to detect secondary ions produced by the sputtering of primary ions. SIMS is one of effective method to measure isotopic composition of particles containing nuclear material in environmental sample for safeguards. We are a group member of the International Atomic Energy Agency (IAEA)'s network of analytical laboratories and have developed analytical techniques using SIMS and other mass spectrometers for nuclear safeguards. We will introduce the principle of SIMS and analytical techniques developed by our group to measure isotopic composition of uranium particles which having a particle diameter of micron order in environmental sample for safeguards.

Journal Articles

Estimation of external dose for wild Japanese macaques captured in Fukushima prefecture; Decomposition of electron spin resonance spectrum

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.

Radiation Protection Dosimetry, 199(14), p.1620 - 1625, 2023/09

 Times Cited Count:1 Percentile:34.39(Environmental Sciences)

We have been conducting dose assessments for Japanese macaques captured in Fukushima to reveal radiobiological effects on the low-dose expose animals. To accurately determine the external exposure dose, it is desirable to examine the analysis of the CO$$_{2}^{-}$$ radical intensity. We examined ESR spectra of teeth of 10 macaques captured in Fukushima by two spectrum-decomposition algorithms.

1256 (Records 1-20 displayed on this page)