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Takahatake, Yoko; Watanabe, So; Arai, Tsuyoshi*; Sato, Takahiro*; Shibata, Atsuhiro
Applied Radiation and Isotopes, 196, p.110783_1 - 110783_5, 2023/06
Times Cited Count:0 Percentile:0.01(Chemistry, Inorganic & Nuclear)Iwamoto, Toshihiro; Saito, Madoka*; Takahatake, Yoko; Watanabe, So; Watanabe, Masayuki; Naruse, Atsuki*; Tsukahara, Takehiko*
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 4 Pages, 2023/05
Applicability of temperature swing extraction technology employing monoamides was examined for uranium contaminated waste treatment procedure. Separation experiments on simulated target solution with three kinds of monoamides with different structure showed that Ce(IV) in the solution was selectively recovered by the temperature swing extraction operation. Based on the experiments, an appropriate monoamide for the procedure was selected.
Arai, Yoichi; Hasegawa, Kenta; Watanabe, So; Watanabe, Masayuki; Minowa, Kazuki*; Matsuura, Haruaki*; Hagura, Naoto*; Katsuki, Kenta*; Arai, Tsuyoshi*; Konishi, Yasuhiro*
Journal of Radioanalytical and Nuclear Chemistry, 9 Pages, 2023/00
Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)Collaborative Laboratories for Advanced Decommissioning Science; The University of Electro-Communications*
JAEA-Review 2022-029, 37 Pages, 2022/11
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 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 FY2019, this report summarizes the research results of the "Semiautonomous remote-control technology of an articulated mobile robot to recover from stuck states" conducted from FY2019 to FY2021. Since the final year of this proposal was FY2021, the results for three fiscal years were summarized. The purpose of this work is to establish a recovery method of an articulated mobile robot from stuck states. In this work, a control method of the robot to recover from stuck states by using redundancy of the system is proposed. In addition, we develop two interfaces. One is a display interface as an operator can understand the situation of the robot and surrounding terrain, and the other is a control interface to provide a target motion using the proposed control method.
Kawaguchi, Koichi; Segawa, Tomoomi; Ishii, Katsunori
Funtai Kogakkai-Shi, 59(6), p.283 - 290, 2022/06
In the Japan Atomic Energy Agency, in order to effectively use the out-of-standard pellets in the fuel manufacturing process for high-speed furnaces, we are developing techniques for crushing and reusing them with raw material powder. By analyzing in detail the particle size distribution before and after grinding, it was shown that the grinding powder is composed of three different component particles having different characteristics of the particle size distribution. In addition, we examined the method of predicting pulverized powder particle size distribution from the supply powder particle size distribution.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Electro-Communications*
JAEA-Review 2021-025, 33 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 "Semi- autonomous remote-control technology of an articulated mobile robot to recover from stuck states" conducted in FY2020. The purpose of this work is to establish a recovery method of an articulated mobile robot from stuck states. In this work, a control method of the robot to recover from stuck states by using redundancy of the system is proposed. In addition, we develop two interfaces. One is a display interface as an operator can understand the situation of the robot and surrounding terrain, and the other is a control interface to provide a target motion using the proposed control method. Finally, the effectiveness of them is demonstrated by experiments using an actual robot.
Saito, Tatsuo; Sato, Kazuhiko; Yamazawa, Hiromi*
Journal of Environmental Radioactivity, 237, p.106708_1 - 106708_9, 2021/10
Times Cited Count:2 Percentile:12.7(Environmental Sciences)We succeeded at numerical reproduction of dissolved U concentrations from column experiments with PO-treated Hanford 300 Area sediment. The time-series curves of dissolved U concentrations under various Darcy flow rate conditions were reproduced by the numerical model in the present study through optimization of the following parameters:(i) the mass of U in mobile domain (on surface soil connected to the stream) and the rest of the total U left as precipitation in immobile domain (isolated in deep soil);(ii) the mixing ratio between immobile and mobile domains, to fit the final recovering curve of concentration; and (iii) the cation exchange capacity (CEC) and equilibrium constant (k) of the exchange reaction of UO and H on simulated soil surface (), to fit the transient equilibrium concentration, forming the bed of the bathtub curve.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Electro-Communications*
JAEA-Review 2020-025, 34 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 FY2019, this report summarizes the research results of the "Semiautonomous Remote-control Technology of an Articulated Mobile Robot to Recover from Stuck States". The purpose of this work is to establish a recovery method of an articulated mobile robot from stuck states. In this work, a control method of the robot to recover from stuck states by using redundancy of the system is proposed. In addition, we develop two interfaces. One is a display interface as an operator can understand the situation of the robot and surrounding terrain, and the other is a control interface to provide a target motion using the proposed control method. Finally, the effectiveness of them is demonstrated by experiments using an actual robot.
Kawaguchi, Koichi; Segawa, Tomoomi; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Ishii, Katsunori
Funtai Kogakkai-Shi, 57(9), p.478 - 484, 2020/09
A collision plate type jet mill is assumed to be a pulverizer that can control the particle size for nuclear fuel fabrication. The collision plate type jet mill consists of two modules, a classifier and a mill chamber. Coarse component of powder is cycled in the equipment and finally pulverized into objective particle size. In this report, simulated crushed powders were classified and pulverized step by step, and particle size distribution were compared. The collision plate type jet mil can produce objective size particles with low overgrinding.
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; Kubota, Toshio*
Nuclear Instruments and Methods in Physics Research B, 477, p.54 - 59, 2020/08
Times Cited Count:5 Percentile:52.81(Instruments & Instrumentation)Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Kubota, Toshio*
QST-M-23; QST Takasaki Annual Report 2018, P. 59, 2020/03
Takeda, Takeshi
JAEA-Data/Code 2018-004, 64 Pages, 2018/03
Experiment SB-SG-10 was conducted on November 17, 1992 using LSTF. Experiment simulated recovery actions from multiple steam generator (SG) tube rupture accident in PWR. Primary pressure was kept higher than broken SG secondary-side pressure due to coolant injection from high pressure injection (HPI) system into cold and hot legs even after start of full opening of intact SG relief valve (RV). Full opening of power-operated relief valve (PORV) in pressurizer (PZR) resulted in pressure equalization between primary and broken SG systems as well as PZR liquid level recovery. Broken SG RV opened once after start of intact SG RV full opening. Core was filled with saturated or subcooled liquid through experiment. Significant natural circulation prevailed in intact loop after start of intact SG RV full opening. Significant thermal stratification appeared in hot legs especially during time period of HPI coolant injection into hot legs.
Choi, B.; Nishida, Akemi; Itoi, Tatsuya*; Takada, Tsuyoshi*
Geosciences (Internet), 8(1), p.1_1 - 1_22, 2018/01
After the Tohoku earthquake in 2011, we observed that aftershocks tended to occur in a wide region after such a large earthquake. These aftershocks resulted in secondary damage or delayed rescue and recovery activities. However, it is difficult to evaluate the hazards of an aftershock before the main shock due to various uncertainties. For possible great earthquakes, we must make decisions based on such uncertainties, and it is important to quantify the various uncertainties. We previously proposed a probabilistic aftershock occurrence model that is expected to be useful to develop plans for recovery activities after future large earthquakes. In this paper, engineering applications of the proposed approach for probabilistic aftershock hazard analysis are shown for demonstration purposes. One application is to use aftershock hazard maps to plan recovery activities. Another application is to derive load combination equations of the load and resistance factor design (LRFD) considering the simultaneous occurrence of tsunamis and aftershocks for the tsunami-resistant design of tsunami evacuation buildings and nuclear facilities.
Kibe, Satoshi; Fujisaku, Kazuhiko*; Sakamoto, Atsushi; Sano, Yuichi; Takeuchi, Masayuki; Suzuki, Hideya; Tsubata, Yasuhiro; Matsumura, Tatsuro
JAEA-Research 2016-024, 40 Pages, 2017/02
The Japan Atomic Energy Agency has been developing some flowsheets with TDdDGA (N,N,N,Ntetradodecyldiglycolamide) extractant to recover MA (minor actinide) from raffinate. In this study, countercurrent experiments with the improved flowsheet, e.g. the addition of alcohol into the solvent for preventing the precipitation, were performed using miniature centrifugal contactors in order to compare the extraction/stripping behavior of each element with the mixer-settler type. As a result, no entrainments were observed and sufficient phase separation was achieved by centrifugal contactors without any abnormal fluid behavior, such as overflow. The extraction and stripping of Ln(III) which show the similar tendencies as MA could be achieved successfully, especially their stripping proceeded more efficiently in centrifugal contactors. This might be due to the increase in stripping rates by improving the flowsheet and to superior phase separation performance of centrifugal contactors.
Fukaya, Masaaki*; Hata, Koji*; Akiyoshi, Kenji*; Sato, Shin*; Takeda, Nobufumi*; Miura, Norihiko*; Uyama, Masao*; Kaneda, Tsutomu*; Ueda, Tadashi*; Hara, Akira*; et al.
JAEA-Technology 2016-002, 195 Pages, 2016/03
The researches on examination of the plug applied to the future reflood test was conducted as a part of (5) development of technologies for restoration and/on reduction of the excavation damage relating to the engineering technology in the MIU (2014), specifically focused on (1) plug examination (e.g. functions, structure and material) and the quality control methods and (2) analytical evaluation of rock mass behavior around the plug through the reflood test. As the result, specifications of the plug were determined. These specifications should be able to meet requirements for the safety structure and surrounding rock mass against predicted maximum water pressure, temperature stress and seismic force, and for controlling the groundwater inflow, ensuring the access into the reflood gallery and the penetration performance of measurement cable. Also preliminary knowledge regarding the rock mass behavior around the plug after flooding the reflood gallery by installed plug was obtained.
Kibe, Satoshi; Fujisaku, Kazuhiko*; Ambai, Hiromu; Sakamoto, Atsushi; Sano, Yuichi; Takeuchi, Masayuki; Suzuki, Hideya; Tsubata, Yasuhiro; Matsumura, Tatsuro
JAEA-Research 2015-021, 40 Pages, 2016/02
The flowsheet with TDdDGA extractant has been being developed for recovering MA from PUREX raffinate. In the previous study, the yields of MA and other elements in countercurrent extraction/stripping experiments using mixer-settlers were not enough for the target and it would be due to the insufficient phase (aqueous/organic) separation. In this study, we carried out countercurrent experiments with surrogate PUREX raffinate using centrifugal contactors which had superior phase separation ability, and evaluated the extraction/stripping behavior of each element. During the operation, abnormal fluid behavior, such as overflow and entrainment, was not observed, and sufficient phase separation was achieved by centrifugal contactors. Extraction behavior of lanthanides was similar to that in mixer-settlers, but their stripping efficiencies decreased. This would be due to shorter residence time in mixing zone.
Awual, M. R.; Hasan, M. M.*; Naushad, M.*; Shiwaku, Hideaki; Yaita, Tsuyoshi
Sensors and Actuators B; Chemical, 209, p.790 - 797, 2015/03
Times Cited Count:158 Percentile:99.25(Chemistry, Analytical)Takayama, Yusuke; Sato, Toshinori; Onoe, Hironori; Iwatsuki, Teruki; Saegusa, Hiromitsu; Onuki, Kenji
Dai-43-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.313 - 318, 2015/01
In the Mizunami Underground Research Laboratory, groundwater recovery experiment is being conducted to construct the method to understand the transition of geological environment due to groundwater recovery at the -500m access and research gallery-north. As a part of this experiment, backfill test is planned using drilling pits filled with artificial materials (clay and concrete) to evaluate the influence on the surrounding rock mass due to the interaction of rock and artificial materials. In this study, numerical simulation of the backfill test has been carried out to predict the qualitative hydro-mechanical behavior.
Seya, Michio; Kureta, Masatoshi; Soyama, Kazuhiko; Nakamura, Hironobu; Harada, Hideo; Hajima, Ryoichi
Proceedings of INMM 55th Annual Meeting (Internet), 10 Pages, 2014/07
JAEA has been implementing development programs of basic technologies of the following advanced NDA (non-destructive assay) of nuclear material (NM) for nuclear safeguards and security. (1) Alternative to He neutron detection using ZnS/BO ceramic scintillator, (2) NRD (neutron resonance densitometry) using NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis), (3) NRF (nuclear resonance fluorescence)-NDA using laser Compton scattered (LCS) -rays (intense mono-energetic -rays). The development program (1) is for NDA systems that use ZnS/BO ceramic scintillator as alternative neutron detector to He for coming shortage of its supply. The program (2) is for a NDA system of isotopic composition measurement (non-destructive mass spectroscopy) in targets such as particle-like melted fuel debris using NRTA and NRCA. The program (3) is for NDA systems using a specific NRF reaction of certain Pu/U isotope caused by mono-energetic LCS -ray with energy tuned to the specific excited state of the isotope. This paper introduces above three programs.
Kawamura, Yoshinori; Enoeda, Mikio; Yamanishi, Toshihiko; Nishi, Masataka
Fusion Engineering and Design, 81(1-7), p.809 - 814, 2006/02
Times Cited Count:14 Percentile:68.04(Nuclear Science & Technology)Tritium bred in the solid breeder blanket of a fusion reactor is extracted by passing of a helium sweep gas. Tritium is separated from sweep gas at the blanket tritium recovery system. Palladium membrane diffuser is one of the applicable processes for the blanket tritium recovery system. It is usually applied for hydrogen purification system such as TEP in ITER. However, it has been reported that the rate controlling step changes at lower hydrogen pressure such as the blanket sweep gas condition, and discussion about application for the blanket sweep gas condition is not enough. Recently, conceptual design of the demonstration reactor, named "DEMO2001", has been proposed from JAERI. In this report, the application of the Pd diffuser for the blanket sweep gas condition is discussed based on the condition of DEMO 2001.