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Onuki, Yoshichika*; Kaneko, Yoshio*; Aoki, Dai*; Nakamura, Ai*; Matsuda, Tatsuma*; Nakashima, Miho*; Haga, Yoshinori; Takeuchi, Tetsuya*
Journal of the Physical Society of Japan, 91(6), p.065002_1 - 065002_2, 2022/06
Times Cited Count:0 Percentile:0.01(Physics, Multidisciplinary)Onuki, Yoshichika*; Nakamura, Ai*; Aoki, Dai*; Matsuda, Tatsuma*; Haga, Yoshinori; Harima, Hisatomo*; Takeuchi, Tetsuya*; Kaneko, Yoshio*
Journal of the Physical Society of Japan, 91(6), p.064712_1 - 064712_10, 2022/06
Times Cited Count:0 Percentile:0.01(Physics, Multidisciplinary)Matsuda, Shohei; Yokoyama, Keiichi; Yaita, Tsuyoshi; Kobayashi, Toru; Kaneta, Yui; Simonnet, M.; Sekiguchi, Tetsuhiro; Honda, Mitsunori; Shimojo, Kojiro; Doi, Reisuke; et al.
Science Advances (Internet), 8(20), p.eabn1991_1 - eabn1991_11, 2022/05
Times Cited Count:0 Percentile:0(Multidisciplinary Sciences)no abstracts in English
Koizumi, Takatsugu*; Honda, Fuminori*; Sato, Yoshiki*; Li, D.*; Aoki, Dai*; Haga, Yoshinori; Gochi, Jun*; Nagasaki, Shoko*; Uwatoko, Yoshiya*; Kaneko, Yoshio*; et al.
Journal of the Physical Society of Japan, 91(4), p.043704_1 - 043704_5, 2022/04
Times Cited Count:0 Percentile:0.01(Physics, Multidisciplinary)Abe, Satoshi; Hamdani, A.; Ishigaki, Masahiro*; Shibamoto, Yasuteru
Annals of Nuclear Energy, 166, p.108791_1 - 108791_18, 2022/02
Times Cited Count:1 Percentile:48.83(Nuclear Science & Technology)Sasagawa, Tsuyoshi; Mukai, Masayuki; Sawaguchi, Takuma
JAEA-Data/Code 2021-012, 122 Pages, 2022/01
Reducing public dose is required when radioactive wastes such as high-level and from reactor core internals etc. are disposed of by means of multi barrier system consist of engineered and natural barriers. In these barriers, engineered barrier is expected to bring out confinement function of waste's radionuclides in the barrier. Materials used as the engineered barriers are altered and performances of the barrier materials are degraded in course of time. To estimate properly the degraded performances, analytical evaluation of long-term change of the engineered barrier state is important. Change state of the engineered barrier is given by mass-transport and geochemical-reaction inside the barrier materials and these phenomena are interrelated, it is necessary to calculate the state by means of coupled analysis procedure. We have developed a coupled mass-transport and geochemical-reaction calculation code (MC- BUFFER) to evaluate alteration of engineered barrier specially targeted for water permeability of bentonite buffer material as one of most important performances to engineered barrier. This report describes functions expected for the engineered barrier, influence parameters for the functions, implementation models in MC-BUFFER, structure and functions of MC-BUFFER, input file format and output examples, execution method of MC-BUFFER, and sample run with MC-BUFFER.
Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Advanced Industrial Science and Technology*
JAEA-Review 2021-026, 47 Pages, 2021/11
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of radiation hardened diamond image sensing devices" conducted in FY2020. The research objective of this project is to develop image sensing devices which work under the high radiation condition. The devices will be realized using radiation hardened diamond semiconductor devices as charge transfer devices and photodetectors. The research project has mainly two targets such as to confirm charge coupled devices operation on diamond unipolar devices and to characterize photo conductivity of diamond detectors.
Zhang, T.*; Morita, Koji*; Liu, X.*; Liu, W.*; Kamiyama, Kenji
Extended abstracts of the 2nd Asian Conference on Thermal Sciences (Internet), 2 Pages, 2021/10
For the Japanese sodium cooled fast reactor, a fuel subassembly with an inner duct structure (FAIDUS) was designed to avoid the re-criticality by preventing the large-scale pool formation. In the present study, using the finite volume particle method, the EAGLE ID1 test which was an in-pile test performed to demonstrate the effectiveness of FAIDUS was numerically simulated and the thermal-hydraulic mechanisms underlying the heat transfer process were analyzed.
Yao, Y.*; Cai, R.*; Yang, S.-H.*; Xing, W.*; Ma, Y.*; Mori, Michiyasu; Ji, Y.*; Maekawa, Sadamichi; Xie, X.-C.*; Han, W.*
Physical Review B, 104(10), p.104414_1 - 104414_6, 2021/09
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Proceedings of INMM & ESARDA Joint Virtual Annual Meeting (Internet), 10 Pages, 2021/08
Inoue, Naoko; Noro, Naoko; Kawakubo, Yoko; Sekine, Megumi; Okuda, Masahiro; Hasegawa, Nobuhiko*; Naoi, Yosuke
Proceedings of INMM & ESARDA Joint Virtual Annual Meeting (Internet), 10 Pages, 2021/08
Integrated Support Center for Nuclear Nonproliferation and Nuclear Security (ISCN) of Japan Atomic Energy Agency (JAEA) celebrated its 10th anniversary in December 2020. One of its pillars is capacity building support mainly to Asian countries. 183 trainings were implemented with more than 4,600 participants since its establishment, however, the COVID-19 pandemic impacted in the implementation of the trainings. ISCN/JAEA has started to develop the online trainings since April 2020, and implemented two regional trainings, Physical Protection and State System of Accounting for and Control (SSAC) for IAEA Safeguards in October and November 2020, respectively. The efforts continue in further development of trainings/workshops, including the regional training on Additional Protocol for IAEA Safeguards Agreement Commodity Identification Training, and other two national workshops with foreign instructors. Online training can provide not only training opportunities for those who have difficulty in traveling for security and safety reasons including under the travel restriction by COVID-19 pandemic, but also could serve in making them more effective and efficient, especially by the combination with in-person trainings. The pandemic, as a result, accelerate ISCN/JAEA to develop and implement the online trainings, which key is the international collaboration with the partners including IAEA, DOE/NNSA and Sandia National Laboratories and International Nuclear Nonproliferation and Security Academy (INSA) of the Korea Institute of Nuclear Nonproliferation and Control (KINAC). This paper will provide the efforts of ISCN/JAEA how to address the online training development and implementation, current status, lesson learned, and future plan.
Matsumoto, Yuji*; Haga, Yoshinori; Yamamoto, Etsuji; Takeuchi, Tetsuya*; Miyake, Atsushi*; Tokunaga, Masashi*
Journal of the Physical Society of Japan, 90(7), p.074707_1 - 074707_6, 2021/07
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Noma, Yuichiro*; Kotegawa, Hisashi*; Kubo, Tetsuro*; To, Hideki*; Harima, Hisatomo*; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*; Ito, Kohei*; Nakamura, Ai*; et al.
Journal of the Physical Society of Japan, 90(7), p.073707_1 - 073707_5, 2021/07
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Okudaira, Takuya*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Ninomi, Yudai*; Sakai, Kenji; et al.
Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07
Times Cited Count:1 Percentile:46.35(Physics, Nuclear)Kawamura, Hideyuki; Hirose, Naoki*; Nakayama, Tomoharu*; Ito, Toshimichi
JAEA-Data/Code 2021-004, 34 Pages, 2021/05
The Japan Atomic Energy Agency measured the ocean current across the Tsugaru Strait using an Acoustic Doppler Current Profiler attached on a ferryboat from October 1999 to January 2008. The characteristics of the ocean current in the Tsugaru Strait must be understood for predicting oceanic dispersion of radioactive materials released from nuclear facilities around the strait. Furthermore, it is critical to elucidate the mechanism of the Tsugaru Warm Current from an oceanography viewpoint. The dataset obtained in this investigation consists of daily ocean current data files that record the components of the current speed in the east-west and north-south directions from the surface layer to the bottom layer. The dataset stores 2,211 daily ocean current data files, despite some data periods missing from October 1999 to January 2008. In this study, information on the dataset is described for users to analyze the dataset properly for their purposes. Section 1 provides the background and purpose of the ocean current measurement, Section 2 explains the methodology of measurement using an Acoustic Doppler Current Profiler, and Section 3 explains the record format of the daily ocean current data files and data acquisition rate and presents analysis results. Finally, Section 4 concludes this study.
Koyamada, Koji*; Yu, L.*; Kawamura, Takuma; Konishi, Katsumi*
International Journal of Modeling, Simulation, and Scientific Computing, 12(2), p.2140001_1 - 2140001_19, 2021/04
With the improvement of sensors technologies in various fields such as fluid dynamics, meteorology, and space observation, it is an important issue to derive explanatory models using partial differential equations (PDEs) for the big data obtained from them. In this paper, we propose a technique for estimating linear PDEs with higher-order derivatives for spatiotemporally discrete point cloud data. The technique calculates the time and space derivatives from a neural network (NN) trained on the point cloud data, and estimates the derivative term of the PDE using regression analysis techniques. In the experiment, we computed the error of the estimated PDEs for various meta-parameters for the PDEs with exact solutions. As a result, we found that increasing the hierarchy of NNs to match the order of the derivative terms in the exact solution PDEs and adopting L1 regularization with LASSO as the method of regression analysis increased the accuracy of the model.
Sugiyama, Daisuke*; Nakabayashi, Ryo*; Tanaka, Shingo*; Koma, Yoshikazu; Takahatake, Yoko
Journal of Nuclear Science and Technology, 58(4), p.493 - 506, 2021/04
Times Cited Count:1 Percentile:48.83(Nuclear Science & Technology)Yoshida, Shogo*; Koyama, Takehide*; Yamada, Haruhiko*; Nakai, Yusuke*; Ueda, Koichi*; Mito, Takeshi*; Kitagawa, Kentaro*; Haga, Yoshinori
Physical Review B, 103(15), p.155153_1 - 155153_5, 2021/04
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Miyajima, Yusuke*; Saito, Ayaka*; Kagi, Hiroyuki*; Yokoyama, Tatsunori; Takahashi, Yoshio*; Hirata, Takafumi*
Geostandards and Geoanalytical Research, 45(1), p.189 - 205, 2021/03
Times Cited Count:2 Percentile:28.61(Geochemistry & Geophysics)Uncertainty for elemental and isotopic analyses of calcite by LA-ICP-MS is largely controlled by the homogeneity of the reference materials (RMs) used for normalization and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb, and rare earth elements into calcite through heat- and pressure-induced crystallization from amorphous calcium carbonate that was precipitated from element-doped reagent solution. X-ray absorption spectra showed that U was present as U(VI) in the synthesized calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison to synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The Pb/
Pb ratio in the calcite showed
1% variations, while the
U/
Pb ratio showed 3-24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC-1, with analytical uncertainty as low as
3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions, and is a promising alternative to natural calcite RMs for U-Pb geochronology.
Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Advanced Industrial Science and Technology*
JAEA-Review 2020-027, 27 Pages, 2021/01
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2019. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of radiation hard diamond image sensing devices". The research objective of this project is to develop image sensing devices which work under the high radiation condition. The devices will be realized using radiation hard diamond semiconductor devices as charge transfer devices and photodetectors. The research project has mainly two targets such as to confirm charge coupled devices operation on diamond unipolar devices and to characterize photo conductivity of diamond detectors.