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Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2023-030, 80 Pages, 2024/03
JAEA-Review-2023-030.pdf:4.96MB
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 "Development of a cooperative operation robot system for radiation source exploration" conducted in FY2022. The present study aims to develop a Cooperative Operation Robot system for RAdiation Source Exploration (CORRASE). The multiple robot system provides radiation source exploration with wide field of view, rapidity, and low cost. The radiation source exploration is realized with multiple robots carrying directional gamma-ray detectors determining the incident direction of the incoming gamma-rays. We will develop the system by the final year of this proposal aiming for application in the Fukushima Daiichi Nuclear Power Station.
, 
, and X-rays (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development ProjectCollaborative Laboratories for Advanced Decommissioning Science; Japan Chemical Analysis Center*
JAEA-Review 2023-022, 93 Pages, 2023/12
JAEA-Review-2023-022.pdf:4.7MB
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 FY2020, this report summarizes the research results of the "Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays" conducted from FY2020 to FY2022. The present study aims to enable rapid analysis of radionuclides in fuel debris and waste, we have established the latest measurement system, such as the multiple -ray detection methods, and the Spectral Determination Method (hereinafter referred to as "SDM") was developed. In the research in 2022, we developed a code that handles measurement data of LSC, singles Ge, and 2D spectra (multiple ). In addition, to develop an integrated database, spectral data of 40 nuclides were obtained by actual measurements and simulation calculations.
Kim, M.; Malins, A.*; Machida, Masahiko; Yoshimura, Kazuya; Saito, Kimiaki; Yoshida, Hiroko*
Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 22(4), p.156 - 169, 2023/11
Dose reduction factor of a Japanese house is important information in the external exposure estimation of returning residents. In 2019, a total of 19 wooden houses were surveyed in Iitate Village and Namie Town using a gamma plotter that can continuously measure the air dose rate. In addition, the characteristics of the reduction factor were investigated from the measured air dose rate. In the vicinity of houses, uncontaminated areas exist underneath houses and, the ratio of paved surfaces such as asphalt roads is relatively high; furthermore, the pavement has a tendency for the radiation source to decay quickly. Therefore, the air dose rate near the house showed a relatively low value in common at all sites. Air dose rates above unpaved surfaces showed higher values and larger variations than those above paved surfaces within a radius of 50 m form the center of a house. The reduction factor was widely distributed even for one house, if the ratio of every air dose rate observed inside and outside the house is considered. It is suggested that a realistic reduction factor may not be obtained when the reduction factor is obtained based on the measured values at a small number of points that do not have the representativeness of the radiation field to be measured.
Furutaka, Kazuyoshi; Ozu, Akira; Toh, Yosuke
Nuclear Engineering and Technology, 55(11), p.4002 - 4018, 2023/11
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Maeda, Makoto; Segawa, Mariko; Toh, Yosuke; Endo, Shunsuke; Nakamura, Shoji; Kimura, Atsushi
Journal of Radioanalytical and Nuclear Chemistry, 332(8), p.2995 - 2999, 2023/08
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)
methodNauchi, Yasushi*; Sato, Shunsuke*; Hayakawa, Takehito*; Kimura, Yasuhiko; Suyama, Kenya; Kashima, Takao*; Futakami, Kazuhiro*
Nuclear Instruments and Methods in Physics Research A, 1050, p.168109_1 - 168109_9, 2023/05
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)Measurement of neutrons from spent nuclear fuel is performed in this study using the H method, which detects 2.223 MeV rays from neutron capture reaction of hydrogen using a highly pure germanium (HPGe) detector. The detection of the 2.223 MeV ray is affected by intense ray emission from fission products (FPs) because the emission rate of rays from the FP is seven orders of magnitude higher than the emission rate of neutrons. To shield the intense ray from the FP, the HPGe detector is placed off the axis of a collimator, whereas a polyethylene block is placed on the axis. In this geometry, the detector is shielded from the intense rays from the FP, but the detector can measure 2.223 MeV rays from the H reactions in the polyethylene block. The measured count rate of the 2.223 MeV rays is consistent with the expected rate within the statistical error, which is calculated based on the nuclide composition, which is primary 
Cm, estimated via depletion and decay calculations. Accordingly, the H method is considered feasible to quantify the number of neutron leakage from spent nuclear fuel assembly, which is applicable to certify burn up of the assembly.
Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takahashi, Tone
Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 5 Pages, 2023/05
Rodriguez, D.; Rossi, F.
Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 9 Pages, 2023/05
Rodriguez, D.; Abbas, K.*; Bertolotti, D.*; Bonaldi, C.*; Fontana, C.*; Fujimoto, Masami*; Geerts, W.*; Koizumi, Mitsuo; Macias, M.*; Nonneman, S.*; et al.
Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 8 Pages, 2023/05
Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2022-041, 76 Pages, 2023/01
JAEA-Review-2022-041.pdf:3.27MB
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 a cooperative operation robot system for radiation source exploration" conducted in FY2021. The present study aims to develop a Cooperative Operation Robot system for RAdiation Source Exploration (CORRASE). The multiple robot system provides radiation source exploration with wide field of view, rapidity, and low cost. The radiation source exploration is realized with multiple robots carrying directional gamma-ray detectors determining the incident direction of the incoming gamma-rays. We will develop the system by the final year of this proposal aiming for application in the Fukushima Daiichi Nuclear Power Station.
, , and X-rays (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development ProjectCollaborative Laboratories for Advanced Decommissioning Science; Japan Chemical Analysis Center*
JAEA-Review 2022-037, 118 Pages, 2023/01
JAEA-Review-2022-037.pdf:6.92MB
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 FY2020, this report summarizes the research results of the "Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays" conducted in FY2021. The present study aims to enable rapid analysis of radionuclides in fuel debris and waste, we have established the latest measurement system, such as the multiple -ray detection methods, and the Spectral Determination Method (hereafter referred to "SDM") was developed. In the study, the -ray measuring device was installed, and the measurement system consisting of the Ge detector, CeBr
detector, and NaI detector was completed in FY2021. In the SDM development, standard spectra of -ray singles, multiple -ray measurements, …
-ray discrimination based on the property and thickness controls of scintillators using Li glass and LiCAF(Ce) in a -ray fieldKaburagi, Masaaki; Shimazoe, Kenji*; Terasaka, Yuta; Tomita, Hideki*; Yoshihashi, Sachiko*; Yamazaki, Atsushi*; Uritani, Akira*; Takahashi, Hiroyuki*
Nuclear Instruments and Methods in Physics Research A, 1046, p.167636_1 - 167636_8, 2023/01
Times Cited Count：3 Percentile：94.27(Instruments & Instrumentation)We focus on the thickness and property controls of inorganic scintillators used for thermal neutron detection in intense -ray fields without considering pulse shape discrimination techniques. GS20
(a lithium glass) and LiCaAlF
:Ce(LiCAF:Ce) cintillators with thicknesses of 0.5 and 1.0 mm, respectively, have been employed. Pulse signals generated by photomultiplier tubes, to which the scintillators were coupled, were inserted into a digital pulse processing unit with 1 Gsps, and the areas of waveforms were integrated for 360 ns. In a 
Co -ray field, the neutron detection for GS20 with a 0.5-mm thickness was possible at dose rates of up to 0.919 Gy/h; however, for LiCAF:Ce, neutron detection was possible at 0.473 Gy/h, and it failed at 0.709 Gy/h. Threfore, in a Co -ray field, the neutron/-ray discrimination of GS20 was better than that of LiCAF:Ce due to its better energy resolution and higher detection efficiency.
Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*
JAEA-Review 2022-027, 85 Pages, 2022/11
JAEA-Review-2022-027.pdf:5.72MB
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 (1F), 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 "Quantitative analysis of radioactivity distribution by imaging of high radiation field environment using gamma-ray imaging spectroscopy" 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 this study, ETCC, a gamma-ray imaging system, was modified to be a portable device that can be used in 1F decommissioning project and can operate in high-dose environments. ETCC is the world's first gamma-ray camera capable of complete bijective imaging, the same as an optical camera. Therefore, ETCC can make general quantitative image analysis methods applicable to radiation, …
Omer, M.; Shizuma, Toshiyuki*; Hajima, Ryoichi*; Koizumi, Mitsuo
Dai-43-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 3 Pages, 2022/11
Nakamura, Hideo; Bentaib, A.*; Herranz, L. E.*; Ruyer, P.*; Mascari, F.*; Jacquemain, D.*; Adorni, M.*
Proceedings of International Conference on Topical Issues in Nuclear Installation Safety; Strengthening Safety of Evolutionary and Innovative Reactor Designs (TIC 2022) (Internet), 10 Pages, 2022/10
-rays of fuel debrisMatsumura, Taichi; Okumura, Keisuke; Fujita, Manabu*; Sakamoto, Masahiro; Terashima, Kenichi; Riyana, E. S.
Radiation Physics and Chemistry, 199, p.110298_1 - 110298_8, 2022/10
Times Cited Count：1 Percentile：29.26(Chemistry, Physical)Urushidate, Tadayuki*; Yoda, Tomoyuki; Otani, Shuichi*; Yamaguchi, Toshio*; Kunii, Nobuaki*; Kuriki, Kazuki*; Fujiwara, Kenso; Niizato, Tadafumi; Kitamura, Akihiro; Iijima, Kazuki
JAEA-Review 2022-023, 8 Pages, 2022/09
JAEA-Review-2022-023.pdf:1.19MB
After the accident of the Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency has newly set up a laboratory in Fukushima and started measuring radioactivity concentrations of environmental samples. In October 2015, Fukushima Radiation Measurement Group has been accredited the ISO/IEC 17025 standard by the Japan Accreditation Board (JAB) as a testing laboratory for radioactivity analysis (
Cs, 
Cs) based on Gamma-ray spectrometry with germanium semiconductor detectors. The laboratory has measured approximately 60,000 of various environmental samples at the end of March 2022. The laboratory quality control and measurement techniques have been accredited by regular surveillance of JAB. In September 2019, the laboratory renewed accreditation as a testing laboratory for radioactivity analysis.
Ho, H. Q.; Ishii, Toshiaki; Nagasumi, Satoru; Ono, Masato; Shimazaki, Yosuke; Ishitsuka, Etsuo; Goto, Minoru; Simanullang, I. L.*; Fujimoto, Nozomu*; Iigaki, Kazuhiko
Nuclear Engineering and Design, 396, p.111913_1 - 111913_9, 2022/09
Times Cited Count：1 Percentile：29.26(Nuclear Science & Technology)Co radiation source under an intense Cs radiation field using an application-specific CeBr
spectrometer suited for use in intense radiation fieldsKaburagi, Masaaki; Shimazoe, Kenji*; Kato, Masahiro*; Kurosawa, Tadahiro*; Takahashi, Hiroyuki*
Journal of Nuclear Science and Technology, 59(8), p.983 - 992, 2022/08
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takahashi, Tone
Proceedings of INMM 63rd Annual Meeting (Internet), 5 Pages, 2022/07
