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CPham, V. H.; Kurata, Masaki; Nagae, Yuji; Ishibashi, Ryo*; Sasaki, Masana*
Corrosion Science, 255, p.113098_1 - 113098_9, 2025/10
Times Cited Count：0Koizumi, Mitsuo; Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Arikawa, Yasunobu*; Abe, Yuki*; Wei, T.*; Yogo, Akifumi*; et al.
Dai-45-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2024/11
Batsaikhan, M.; Oba, Hironori; Karino, Takahiro; Akaoka, Katsuaki; Wakaida, Ikuo
Optics Express (Internet), 32(24), p.42626 - 42638, 2024/11
Times Cited Count：0 Percentile：0.00(Optics)Iwata, Yoshihiro; Miyabe, Masabumi; Wells, S. R.*; Yamamoto, Yuta*; Hasegawa, Shuichi*
Proceedings of International Topical Workshop on Fukushima Decommissioning Research 2024 (FDR2024) (Internet), 4 Pages, 2024/10
In this study, triple and double resonance ionization schemes of atomic Ca were developed, aiming for the separation of odd isotopes by (i) laser polarization-dependent selection rules, and (ii) large isotope shifts of odd Ca isotopes in the Rydberg levels. Separation of odd isotopes was confirmed under the orthogonal condition. Suppression of non-resonant ionization of 
Ca by the electric field in the ionization region could further improve the optical isotope selectivity of 
Ca.
Yanagisawa, Kayo; Yokota, Hiromi*; Fujimoto, Katsushige*; Takagai, Yoshitaka*
Bunseki Kagaku, 73(9), p.515 - 522, 2024/09
On-line isotope dilution-laser ablation-inductively coupled plasma-mass spectrometry (on-line ID-LA-ICP-MS) is capable of quantification for each point ablated by laser, then the quantitative mapping of elements can be also conducted by reconstruction of the obtained each point data. The volume of data obtained as flow peaks in this system as a flow injection analysis, will be multiplied by each data such as number of m/z, scan time, time resolution and measurement position, and the total amount of data is enormous, resulting in a large human power and time consumption for data processing. In this paper, an original application software using Python to improve the efficiency of data processing in on-line ID-LA-ICP-MS was developed. To discriminate between the time-to-peak intensity and the background noise, an automatic peak detection using penalized asymmetric least squares was developed.
Koizumi, Mitsuo; Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Arikawa, Yasunobu*; Abe, Yuki*; Lan, Z.*; Wei, T.*; et al.
Scientific Reports (Internet), 14, p.21916_1 - 21916_9, 2024/09
Times Cited Count：2 Percentile：64.46(Multidisciplinary Sciences)Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2024-031, 75 Pages, 2024/08
JAEA-Review-2024-031.pdf:3.74MB
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 FY2022. 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 FY2021, this report summarizes the research results of the "Research on radioactive aerosol control and decontamination at Fukushima Daiichi Nuclear Power Station decommissioning" conducted in FY2022. The present study aims to develop a safe laser decontamination system that can control aerosol diffusion during laser decontamination while simultaneously allowing advanced particle measurement and evaluation, in cooperation with a research group in the United Kingdom.
Tamura, Koji; Nakanishi, Ryuzo; Oba, Hironori; Karino, Takahiro; Shibata, Takuya; Taira, Takunori*; Wakaida, Ikuo
Journal of Nuclear Science and Technology, 61(8), p.1109 - 1116, 2024/08
Times Cited Count：1 Percentile：23.64(Nuclear Science & Technology)Lan, Z.*; Arikawa, Yasunobu*; Mirfayzi, S. R.*; Morace, A.*; Hayakawa, Takehito*; Sato, Hirotaka*; Kamiyama, Takashi*; Wei, T.*; Tatsumi, Yuta*; Koizumi, Mitsuo; et al.
Nature Communications (Internet), 15, p.5365_1 - 5365_7, 2024/07
Times Cited Count：5 Percentile：75.95(Multidisciplinary Sciences)Batsaikhan, M.; Akaoka, Katsuaki; Saeki, Morihisa*; Karino, Takahiro; Oba, Hironori; Wakaida, Ikuo
Journal of Nuclear Science and Technology, 61(5), p.658 - 670, 2024/05
Times Cited Count：2 Percentile：43.92(Nuclear Science & Technology)no abstracts in English
Seto, Keita
Optics Express (Internet), 32(10), p.16999 - 17011, 2024/05
Times Cited Count：0 Percentile：0.00(Optics)Sano, Tomokazu*; Matsuda, Tomoki*; Hirose, Akio*; Terai, Tomoyuki*; Kakeshita, Tomoyuki*; Inubushi, Yuichi*; Sato, Takahiro*; Yabashi, Makina*; Shobu, Takahisa; 22 of others*
Scientific Reports (Internet), 13, p.13796_1 - 13796_10, 2023/08
Times Cited Count：4 Percentile：37.63(Multidisciplinary Sciences)Ikeda, Yuji*; Soriano, J. K.*; Oba, Hironori; Wakaida, Ikuo
Scientific Reports (Internet), 13, p.4828_1 - 4828_9, 2023/03
Times Cited Count：13 Percentile：94.85(Multidisciplinary Sciences)Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2022-061, 59 Pages, 2023/02
JAEA-Review-2022-061.pdf:2.38MB
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 FY2021. 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 FY2021, this report summarizes the research results of the "Research on radioactive aerosol control and decontamination at Fukushima Daiichi Nuclear Power Station decommissioning" conducted in FY2021. The present study aims to develop a safe laser decontamination system that simultaneously incorporates an advanced particle detection and characterization system together with aerosol dispersion control in collaboration with the UK researchers. By using the UK partner's fundamental studies related to aerosol and water interface interactions, various methods such as electro-chemical processing of water-mist particles and spray droplets will be applied for effective control of ultra-fine aerosol particle dispersions in a large containment volume.
Collaborative Laboratories for Advanced Decommissioning Science; National Institutes of Natural Sciences*
JAEA-Review 2022-059, 34 Pages, 2023/01
JAEA-Review-2022-059.pdf:1.58MB
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 FY2021. 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 FY2021, this report summarizes the research results of the "Development of the continuous monitoring of tritium water by mid-infrared laser spectroscopy" conducted in FY2021. The present study aims to demonstrate the principle of short-time measurement of tritiated water at the "60 Bq/cc level" using a cavity ring-down measurement system with a mid-infrared laser. In order to achieve the above goal, (1) research on the cavity ring-down system and (2) evaluation of hydrogen isotope composition under environmental conditions and preparation of standard samples (subcontractor: Hirosaki University) were conducted this fiscal year. In (1), a mid-infrared cavity ring-down test was conducted. An optical bench (3 m 
1.2 m) was set up in the laboratory, …
Yogo, Akifumi*; Lan, Z.*; Arikawa, Yasunobu*; Abe, Yuki*; Mirfayzi, S. R.*; Wei, T.*; Mori, Takato*; Golovin, D.*; Hayakawa, Takehito*; Iwata, Natsumi*; et al.
Physical Review X, 13(1), p.011011_1 - 011011_12, 2023/01
Times Cited Count：28 Percentile：96.01(Physics, Multidisciplinary)Katsumi, Toshiyuki; Thwe Thwe, A.; Kadowaki, Satoshi
Journal of Visualization, 25(5), p.1075 - 1083, 2022/10
Times Cited Count：2 Percentile：18.12(Computer Science, Interdisciplinary Applications)Lean combustion and inert-gas addition are useful to control the burning velocity of hydrogen premixed flames, and it is well known that the cellular structure forms on the front of lean hydrogen flames owing to intrinsic instability. However, the influences of inert-gas addition on the instability phenomena of lean hydrogen premixed flames are not understood fully, and then it is needed to be investigated the flame instability experimentally. In the experiments, the cellular structure and fluctuation of H
/O/inert gases (Ar, N,CO) premixed flames on a flat burner were obtained using direct observation, laser diagnostics and light emission intensity to elucidate the characteristics of instability phenomena. As the results, the correlation of inert-gas addition, equivalence ratio and total flow rate with the characteristics of cellular flames was revealed, and the influences of these parameters on flame instability were discussed.
Porcheron, E.*; Leblois, Y.*; Journeau, C.*; Delacroix, J.*; Molina, D.*; Suteau, C.*; Berlemont, R.*; Bouland, A.*; Lallot, Y.*; Roulet, D.*; et al.
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR2022) (Internet), 5 Pages, 2022/10
One of the important challenges for the decommissioning of the damaged reactors of the Fukushima Daiichi Nuclear Power Station (1F) is the fuel debris retrieval. The URASOL project, which is undertaken by a French consortium consisting of ONET Technologies, CEA, and IRSN for JAEA/CLADS, is dedicated to acquiring basic scientific data on the generation and characteristics of radioactive aerosols from the thermal or mechanical processing of fuel debris simulant. Heating process undertaken in the VITAE facility simulates some representative conditions of thermal cutting by LASER. For mechanical cutting, the core boring technique is implemented in the FUJISAN facility. Fuel debris simulants have been developed for inactive and active trials. The aerosols are characterized in terms of mass concentration, real time number concentration, mass size distribution, morphology, and chemical properties. The chemical characterization aims at identifying potential radioactive particles released and the associated size distribution, both of which are important information for assessing possible safety and radioprotection measures during the fuel debris retrieval operations at 1F.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2022-015, 119 Pages, 2022/09
JAEA-Review-2022-015.pdf:6.62MB
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 "Analysis of microparticles generated by laser processing and development of a methodology for their nuclear identification" 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. Although laser processing has various advantages, one well-known disadvantage is that it generates a large amount of microparticles during the processing. Therefore, the application of laser processing to decommissioning waste contaminated with radioactive materials has been hesitant because the mechanism generating the microparticles has not been fully understood.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2022-014, 106 Pages, 2022/08
JAEA-Review-2022-014.pdf:10.42MB
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 technology for rapid analysis of strontium-90 with low isotopic abundance using laser resonance ionization" 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. The present study aims to develop a rapid analysis technique for strontium-90 using diode laser-based resonance ionization with elemental and isotopic selectivity. Strontium-90 is one of the major difficult-to-measure nuclides released into the environment due to the accident at TEPCO's Fukushima Daiichi Nuclear Power Station.
