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funabiki, Yuta*; Iyota, Muneyoshi*; Shobu, Takahisa; Matsuda, Tomoki*; Hayashi, Yujiro*; Sano, Tomokazu*; 8 of others*
Journal of Manufacturing Processes, 115, p.40 - 55, 2024/04
Times Cited Count：4 Percentile：74.69(Engineering, Manufacturing)Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*
JAEA-Review 2022-068, 90 Pages, 2023/05
JAEA-Review-2022-068.pdf:3.55MB
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 FY2018, this report summarizes the research results of the "Development of thin SiC neutron detector with high radiation resistance" conducted from FY2018 to FY2021 (this contract was extended to FY2021). Since the final year of this proposal was FY2021, the results for four fiscal years were summarized. In the works for debris retrieval, it is required to install subcritical surveillance radiation monitors that can surely work for long time under extremely high gamma-ray radiation environment. However, there have been problems such as remote control of conventional neutron detectors is difficult because heavy radiation shields are needed.
Iyota, Muneyoshi*; Matsuda, Tomoki*; Sano, Tomokazu*; Shigeta, Masaya*; Shobu, Takahisa; Yumoto, Hirokatsu*; Koyama, Takahisa*; Yamazaki, Hiroshi*; Semba, Yasunori*; Ohashi, Haruhiko*; et al.
Journal of Manufacturing Processes, 94, p.424 - 434, 2023/05
Times Cited Count：8 Percentile：66.71(Engineering, Manufacturing)Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Technology, Kisarazu College*
JAEA-Review 2021-043, 135 Pages, 2022/01
JAEA-Review-2021-043.pdf:5.39MB
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 FY2018, this report summarizes the research results of the "Development of dosimetry device in reactor cores under severe radiation environment" conducted from FY2018 to FY2020. Since the final year of this proposal was FY2020, the results for three fiscal years were summarized. Since the radiation level in the reactors and buildings of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (1F) is extremely high due to the accident, it is required to develop radiation measurement technology based on the needs at the 1F working site. In this study, we will develop technologies towards practical application of revolutionary radiation measurement system based on the dose measurement technology utilizing solar cell devices.
Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Technology, Kisarazu College*
JAEA-Review 2020-051, 97 Pages, 2021/02
JAEA-Review-2020-051.pdf:5.02MB
JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Dosimeter for Severe Radiation Environment near Reactor Pressure Vessel" conducted in FY2019.
Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*
JAEA-Review 2020-057, 50 Pages, 2021/01
JAEA-Review-2020-057.pdf:2.82MB
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 FY2018, this report summarizes the research results of the "Development of Thin SiC Neutron Detector with High Radiation Resistance" conducted in FY2019. In the works for debris retrieval, it is required to install subcritical surveillance radiation monitors that can surely work for long time under extremely high gamma-ray radiation environment. However, there have been problems such as remote control of conventional radiation monitors is difficult because heavy radiation shields are needed. In the present study, we will develop a neutron detector using thin, light-weight and radiation-resistive silicon carbide (SiC) that has low sensitivity to gamma-rays as well as the data collection system in collaboration with the U.K.
Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*
JAEA-Review 2020-030, 55 Pages, 2020/12
JAEA-Review-2020-030.pdf:2.76MB
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 FY2018, this report summarizes the research results of the "Development of hydrogels for prevention of radioactive dust dispersion during fuel debris retrieval" conducted in FY2019. In this study, we propose coating fuel debris with thixotropic gel materials to suppress dust dispersion during debris retrieval. Hectorite clay mineral - borax composite gel was selected based on the viscosity, the transparency and the radiation resistance. Simulated cutting tests confirm that the gel coating effectively suppress the dust dispersion.
Narukawa, Takafumi; Amaya, Masaki
Journal of Nuclear Science and Technology, 57(7), p.782 - 791, 2020/07
Times Cited Count：7 Percentile：55.56(Nuclear Science & Technology)Aoki, Takeshi; Chirayath, S. S.*; Sagara, Hiroshi*
Annals of Nuclear Energy, 141, p.107325_1 - 107325_7, 2020/06
Times Cited Count：2 Percentile：17.88(Nuclear Science & Technology)The proliferation resistance (PR) of an inert matrix fuel (IMF) in the transuranic nuclear fuel cycle (NFC) of a high temperature gas cooled reactor is evaluated relative to the uranium and plutonium mixed-oxide (MOX) NFC of a light water reactor using PRAETOR code and sixty-eight input attributes. The objective is to determine the impacts of chemical stability of IMF and fuel irradiation on the PR. Specific material properties of the IMF, such as lower plutonium content, carbide ceramics coating, and absence of 
U, contribute to enhance its relative PR compared to MOX fuel. The overall PR value of the fresh IMF (an unirradiated direct use material with a one-month diversion detection timeliness goal) is nearly equal to that of the spent MOX fuel (an irradiated direct use nuclear material with a three-month diversion detection timeliness goal). Final results suggest a reduced safeguards inspection frequency to manage the IMF.
Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*
JAEA-Review 2019-042, 43 Pages, 2020/03
JAEA-Review-2019-042.pdf:25.64MB
JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. 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. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Thin SiC Neutron Detector with High Radiation Resistance". In the works for debris retrieval, it is required to install subcritical surveillance radiation monitors that can surely work for long time under extremely high gamma-ray radiation environment. However, there have been problems such as remote control of conventional radiation monitors is difficult because heavy radiation shields are needed. In the present study, we will develop a neutron detector using thin, light-weight and radiation-resistive silicon carbide (SiC) that has low sensitivity to gamma-rays as well as the data collection system in collaboration with the U.K. Using this system, the performance tests will be conducted supposing the real debris retrieval including the irradiation tests. Based on the results, we will conduct research and development aiming to make the system ready for use in real decommissioning works.
Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Technology, Kisarazu College*
JAEA-Review 2019-033, 57 Pages, 2020/03
JAEA-Review-2019-033.pdf:3.17MB
JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. 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. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Dosimeter for Severe Radiation Environment near Reactor Pressure Vessel". Since the radiation level in the reactors and buildings of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (1F) is extremely high due to the accident, it is required to develop radiation measurement technology based on the needs at the 1F working site. In the previous studies, it has been verified that dosimeters using solar cell devices can be used for dose evaluation under high dose rate near the reactor pressure vessel because they have advantages such as unnecessity of a high-voltage source, ultra-compactness, lightweight, and high radiation resistance. Through this study, we will develop technologies towards practical application of revolutionary radiation measurement system based on the dose measurement technology utilizing solar cell devices.
Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*
JAEA-Review 2019-029, 36 Pages, 2020/02
JAEA-Review-2019-029.pdf:2.33MB
JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. 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 FY2018, this report summarizes the research results of the "Development of Gel Filler that Facilitates Fuel Debris Retrieval". When gel materials such as polymer, silicate and clay minerals with adjusted viscosity are used in the process of debris retrieval, the gel would not leak down from the damaged parts, resulting in the reduction of surrounding air dose rate. In addition, gel materials can reduce the diffusion and scattering of dust that is produced by cutting. For these reasons, we propose a method where inside of a containment vessel is filled by gel materials in order to simplify the debris retrieval.
Ito, Chikara; Naito, Hiroyuki; Ishikawa, Takashi; Ito, Keisuke; Wakaida, Ikuo
JPS Conference Proceedings (Internet), 24, p.011038_1 - 011038_6, 2019/01
A high-radiation resistant optical fiber has been developed in order to investigate the interiors of the reactor pressure vessels and the primary containment vessels at the Fukushima Daiichi Nuclear Power Station. The tentative dose rate in the reactor pressure vessels is assumed to be up to 1 kGy/h. We developed a radiation resistant optical fiber consisting of a 1000 ppm hydroxyl doped pure silica core and 4 % fluorine doped pure silica cladding. We attempted to apply the optical fiber to remote imaging technique by means of fiberscope. The number of core image fibers was increased from 2000 to 22000 for practical use. The transmissive rate of infrared images was not affected after irradiation of 1 MGy. No change in the spatial resolution of the view scope by means of image fiber was noted between pre- and post-irradiation. We confirmed the applicability of the probing system, which consists of a view scope using radiation-resistant optical fibers.
Wakaida, Ikuo; Oba, Hironori; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tamura, Koji; Saeki, Morihisa
Kogaku, 48(1), p.13 - 20, 2019/01
By Laser Induced Breakdown Spectroscopy and by related resonance spectroscopy, elemental and isotope analysis of Uranium and Plutonium for nuclear fuel materials and in-situ remote analysis under strong radiation condition for melt downed nuclear fuel debris at damaged core in "Fukushima Daiichi Nuclear Power Station", are introduced and performed as one of the application in atomic energy research field.
Zaiton, A.*; Ono, Yutaka
JAEA-Review 2015-037, 120 Pages, 2016/03
JAEA-Review-2015-037.pdf:15.19MB
This report summarizes Bilateral Cooperative Research between Japan Atomic Energy Agency and Malaysian Nuclear Agency (a representative of the Government of Malaysia) implemented from 2002 to 2012 under "THE IMPLEMENTING ARRANGEMENT BETWEEN THE GOVERNMENT OF MALAYSIA AND THE JAPAN ATOMIC ENERGY AGENCY ON THE RESEARCH COOPERATION IN THE FIELD OF RADIATION PROSSING". The research activities in two Cooperative Research Programs, "Mutation Induction of Orchid Plants by Ion Beams" and "Generating New Ornamental Plant Varieties Using Ion Beams" performed 2002-2007 and 2007-2012, respectively, are contained. The lists of steering committee meetings, irradiation experiments, and publications/presentations of each program are also attached in the Appendixes.
Goto, Minoru; Demachi, Kazuyuki*; Ueta, Shohei; Nakano, Masaaki*; Honda, Masaki*; Tachibana, Yukio; Inaba, Yoshitomo; Aihara, Jun; Fukaya, Yuji; Tsuji, Nobumasa*; et al.
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.507 - 513, 2015/09
A concept of a plutonium burner HTGR named as Clean Burn, which has a high nuclear proliferation resistance, had been proposed by Japan Atomic Energy Agency. In addition to the high nuclear proliferation resistance, in order to enhance the safety, we propose to introduce PuO
-YSZ TRISO fuel with ZrC coating to the Clean Burn. In this study, we conduct fabrication tests aiming to establish the basic technologies for fabrication of PuO-YSZ TRISO fuel with ZrC coating. Additionally, we conduct a quantitative evaluation of the security for the safety, a design of the fuel and the reactor core, and a safety evaluation for the Clean Burn to confirm the feasibility. This study is conducted by The University of Tokyo, Japan Atomic Energy Agency, Fuji Electric Co., Ltd., and Nuclear Fuel Industries, Ltd. It was started in FY2014 and will be completed in FY2017, and the first year of the implementation was on schedule.
Chiba, Atsuya; Uno, Sadanori; Okoshi, Kiyonori; Yamada, Keisuke; Saito, Yuichi; Ishii, Yasuyuki; Sakai, Takuro; Sato, Takahiro; Mizuhashi, Kiyoshi
JAEA-Review 2005-001, TIARA Annual Report 2004, p.358 - 360, 2006/01
no abstracts in English
exchange processes into a multilayer atmosphere-soil-vegetation modelNagai, Haruyasu
Journal of Applied Meteorology, 44(10), p.1574 - 1592, 2005/10
This paper describes the incorporation of CO exchange processes into an atmosphere-soil-vegetation model SOLVEG and examination of its sensitivity and impact of its stomatal resistance calculation on the latent heat flux over a winter wheat field. The model framework for the heat and water exchanges between the atmosphere and ground surface was validated in the previous papers (Nagai 2002, 2003). In this study, CO exchange processes are incorporated in the model and the performance is examined. In the test calculation, the model simulated the CO flux at 2 m above the ground well as a whole. A sensitivity test to clarify uncertainties for the model settings and parameters showed that the CO production in the soil is the most important factor for the CO calculation. Also, the impact of the CO processes on the latent heat flux is discussed. The results indicate that the new model is effective and preferable to study surface exchanges of heat and water as well as CO.
Morioka, Atsuhiko; Sakurai, Shinji; Okuno, Koichi*; Tamai, Hiroshi
Purazuma, Kaku Yugo Gakkai-Shi, 81(9), p.645 - 646, 2005/09
A 300 
C heat-resistant neutron shielding material is newly developed, which consists of phenol-based resin with 5 weight-% boron. The neutron shielding performance of the developed resin, examined by the 
Cf neutron source, is almost the same as that of the polyethylene. The resin is applicable to the port section of vacuum vessel of the DD plasma device to suppress the streaming neutrons and to reduce the nuclear heating of the superconducting coils.
hole-assisted electronic processes in the Pr
Sr
MnO
(x=0.0, 0.3) systemIbrahim, K.*; Qian, H. J.*; Wu, X.*; Abbas, M. I.*; Wang, J. O.*; Hong, C. H.*; Su, R.*; Zhong, J.*; Dong, Y. H.*; Wu, Z. Y.*; et al.
Physical Review B, 70(22), p.224433_1 - 224433_9, 2004/12
Times Cited Count：31 Percentile：75.87(Materials Science, Multidisciplinary)no abstracts in English
