Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*
JAEA-Review 2022-068, 90 Pages, 2023/05
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:3 Percentile:57.26(Engineering, Manufacturing)Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Technology, Kisarazu College*
JAEA-Review 2021-043, 135 Pages, 2022/01
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 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/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
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
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.
Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*
JAEA-Review 2019-042, 43 Pages, 2020/03
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/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/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.
Hayashi, Hirotaka*; Wada, Seiichi; Funayama, Tomoo; Narumi, Issei; Kobayashi, Yasuhiko; Watanabe, Hiroshi*; Furuta, Masakazu*; Uehara, Kaku*
Journal of Eukaryotic Microbiology, 51(3), p.321 - 324, 2004/06
Times Cited Count:5 Percentile:6.62(Microbiology)no abstracts in English
Baba, Shinichi; Ishihara, Masahiro; Sozawa, Shizuo; Sekino, Hajime
JAERI-Data/Code 2003-003, 394 Pages, 2003/03
The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and -ray spectrum are reported.
Nagai, Haruyasu
Journal of Applied Meteorology, 42(3), p.434 - 451, 2003/03
This paper describes the improvement of an atmosphere-soil-vegetation model and the validation of the new model by observation. In the previous performance test using measured data, some limitations were revealed in the schemes for the canopy radiation transmission and the stomatal resistance calculation, and are improved in this study. By these improvements, the observed albedo and latent heat flux are simulated more properly than before. Results of comparisons between calculations and observations for a winter wheat field and a grassland indicate that the predictability and applicability are improved by the introduction of the new schemes.
Oka, Kiyoshi; Shibanuma, Kiyoshi
Advanced Robotics, 16(6), p.493 - 496, 2002/12
Times Cited Count:8 Percentile:39.11(Robotics)no abstracts in English
Kiuchi, Kiyoshi; Ioka, Ikuo; Tachibana, Katsumi; Suzuki, Tomio; Fukaya, Kiyoshi*; Inohara, Yasuto*; Kambara, Shozo; Kuroda, Yuji*; Miyamoto, Satoshi*; Ogura, Kazutomo*
JAERI-Research 2002-008, 63 Pages, 2002/03
no abstracts in English
Nagai, Haruyasu
Journal of Applied Meteorology, 41(2), p.160 - 176, 2002/02
no abstracts in English
Sato, Katsuya; Narumi, Issei; Kikuchi, Masahiro; Kitayama, Shigeru; Yanagisawa, Tadashi*; Yamamoto, Kazuo; Watanabe, Hiroshi
Journal of Biochemistry, 131(1), p.121 - 129, 2002/01
Times Cited Count:25 Percentile:38.61(Biochemistry & Molecular Biology)RecA protein is considered to be the most important participant in the radiation resistance of . We identified a new mutation () in the DNA-repair deficient mutant strain KI696, the phenotype of which is remarkably different from mutant strain rec30 carrying . In vitro, neither RecA424 nor RecA670 could promote DNA strand exchange, indicating that both RecA424 and Rec670 are defective in recombination activity. RecA424 promoted the autocleavage reaction of LexA in vitro, whereas RecA670 did not. The LexA level in KI696 was decreased following -irradiation. However, the LexA level in strain rec30 was constant irrespective of irradiation. These results indicate that RecA424 retains co-protease activity, whereas RecA670 does not. While strain rec30 is extremely radiation sensitive, strain KI696 is only slightly sensitive. Together, these observations suggest that the co-protease activity rather than the recombination activity of RecA contributes to the radiation resistance in .
Seguchi, Tadao; Kudo, Hisaaki; Sugimoto, Masaki; *
Nuclear Instruments and Methods in Physics Research B, 151(1-4), p.154 - 160, 1999/00
Times Cited Count:25 Percentile:84.89(Instruments & Instrumentation)no abstracts in English
Oshima, Akihiro; Ikeda, Shigetoshi*; Seguchi, Tadao; Tabata, Yoneho*
Preprints of 6th SPSJ International Polymer Conference, P. 237, 1997/00
no abstracts in English