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Li, L.*; Miyamoto, Goro*; Zhang, Y.*; Li, M.*; Morooka, Satoshi; Oikawa, Katsunari*; Tomota, Yo*; Furuhara, Tadashi*
Journal of Materials Science & Technology, 184, p.221 - 234, 2024/06
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)Miyakawa, Kazuya; Nakata, Kotaro*
JAEA-Data/Code 2022-013, 19 Pages, 2023/03
JAEA-Data-Code-2022-013.pdf:1.88MB
In the Horonobe Underground Research Laboratory (URL) project, groundwater chemistry was analyzed to investigate changes due to the excavation of the underground facility and to review geochemical models until the fiscal year 2019. From the fiscal year 2020, to proceed remaining important issues deduced from the conclusion of the investigations during the fiscal year 2015-2019, primary data such as groundwater chemistry need to be successively acquired. Here, the chemical analysis of 54 groundwater samples in 2022 from boreholes drilled in the 140 m, 250 m, 350 m gallery in the Horonobe URL, and water rings settled in three vertical shafts is presented. Analytical results include groundwater chemistry such as pH, electrical conductivity, dissolved components (Na
, K, Ca
, Mg, Li, NH
, F
, Cl, Br, NO
, NO
, PO
, SO
, Total-Mn, Total-Fe, Al, B, Sr, Ba, I, alkalinity, dissolved organic carbon, dissolved inorganic carbon, CO, HCO, Fe, sulfide), and 
O, D along with a detailed description of analytical methods.
Im, S.*; Jee, H.*; Suh, H.*; Kanematsu, Manabu*; Morooka, Satoshi; Koyama, Taku*; Nishio, Yuhei*; Machida, Akihiko*; Kim, J.*; Bae, S.*
Journal of the American Ceramic Society, 104(9), p.4803 - 4818, 2021/09
Times Cited Count：18 Percentile：83.57(Materials Science, Ceramics)Kitamura, Akira; Yoshida, Yasushi*
Journal of Radioanalytical and Nuclear Chemistry, 327(2), p.839 - 845, 2021/02
Times Cited Count：3 Percentile：43.41(Chemistry, Analytical)Thermodynamic data for radium for radioactive waste management have been predicted using an electrostatic model and correlation with the ionic radii of the alkaline earth metals. Estimation of the standard Gibbs free energy of formation and standard molar entropy of aqueous radium species and compounds has been based on such approaches as extrapolation of the thermodynamic properties of strontium and barium, and use of a model of ion pair formation. The predicted thermodynamic data for radium have been compared with previously reported values.
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Polytechnic University*
JAEA-Review 2020-062, 47 Pages, 2021/01
JAEA-Review-2020-062.pdf:3.43MB
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 Semantic Survey Map Building System using Semi-autonomous Mobile Robots for Surveying of Disaster Area and Gathering of Information in Nuclear Power Station" conducted in FY2019.
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Polytechnic University*
JAEA-Review 2019-022, 35 Pages, 2020/01
JAEA-Review-2019-022.pdf:2.71MB
CLADS, JAEA, 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 Semantic Survey Map Building System Using Semi-autonomous Mobile Robots for Surveying of Disaster Area and Gathering of Information in Nuclear Power Station. The objective of the present study is to research and develop semi-autonomous mobile robot systems (multi-sensor fusion system, semantic simultaneous localization and mapping (SLAM), system for traversable-route learning and safe traversable-route presentation, etc.) that simply, safely, and rapidly make semantic survey maps including multiple information (air dose rate, temperature, obstacles, etc.). The system will be applied to the investigation of the situation inside the building of the nuclear power station where people cannot access at the time of disaster.
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji
Nuclear Materials and Energy (Internet), 16, p.230 - 237, 2018/08
Times Cited Count：4 Percentile：37.66(Nuclear Science & Technology)Nakata, Kotaro*; Hasegawa, Takuma*; Oyama, Takahiro*; Ishii, Eiichi; Miyakawa, Kazuya; Sasamoto, Hiroshi
Geofluids, 2018, p.7823195_1 - 7823195_21, 2018/01
Times Cited Count：9 Percentile：56.38(Geochemistry & Geophysics)A groundwater scenario is one of the scenario for safety assessment of geological disposal of high-level radioactive waste. In the safety assessment for groundwater scenario, the slow groundwater flow for a long-term should be an important factor. In the present study, study on stability of groundwater in the Koetoi and Wakkanai formations of Neogene marine based sedimentary rock at the Horonobe area, Hokkaido was performed by investigating the isotopes of chlorine and helium, and the stable isotopes of water. As the results, the stability of groundwater in deeper part of the Wakkanai formation was suggested due to no direct evidence of meteoric water intrusion during the uplift since ca. 1 Ma. Contrary, the groundwater both in the Koetoi formation and the upper Wakkanai formation would be unstable because the meteoric water intrusion was suggested by paleohydrogeological condition and the results of groundwater dating. Likely the Horonobe area, the accurate dating of groundwater would be difficult due to the complex effects of upward and mixing water derived from diagenesis in the thick sediment formation. However, a comparative procedure using both the results of groundwater dating and paleohydrogeological information would be useful for general evaluation of groundwater flow conditions for the long-term (i.e., check the possibility for long-term stability of groundwater).
Fukuda, Yuji; Kishimoto, Yasuaki; Masaki, Tomohiro*; Yamakawa, Koichi
Physical Review A, 73(3), p.031201_1 - 031201_4, 2006/03
Times Cited Count：35 Percentile：79.37An ultrashort, intense laser-cluster interaction and a resultant structure formation are investigated in detail by employing a particle code including relaxation and ionization processes. In addition to a laser-induced polarization field, we have found that an ambipolar radial electric field and an internal/external sheath field play a key role in a disassembling dynamics of the cluster. Electrons and ions show a complex behavior leading to a prominent dip structure in electron energy distribution and a double structure in ion density and energy distributions for higher charge states.
Shibata, Taiju; Sumita, Junya; Baba, Shinichi; Yamaji, Masatoshi*; Ishihara, Masahiro; Iyoku, Tatsuo; Tsuji, Nobumasa*
Key Engineering Materials, 297-300, p.728 - 733, 2005/11
no abstracts in English
Nakahira, Masataka
JAERI-Research 2005-030, 182 Pages, 2005/09
JAERI-Research-2005-030.pdf:12.57MB
It is difficult for Vacuum Vessel (VV) of ITER to apply a non-destructive in-service inspection (ISI) and then new safety concept is needed. Present fabrication standards are not applicable to the VV, because the access is limited to the backside of closure weld of double wall. Fabrication tolerance of VV is 
5mm even the structure is huge as high as 10m. This accuracy requires a rational method on the estimation of welding deformation. In this report, an inherent safety feature of the tokamak is proved closing up a special characteristic of termination of fusion reaction due to tiny water leak. A rational concept not to require ISI without sacrificing safety is shown based on this result. A partial penetration T-welded joint is proposed to establish a rational fabrication method of double wall. Strength and susceptibility to crevice corrosion is evaluated for this joint and feasibility is confirmed. A rational method of estimation of welding deformation for large and complex structure is proposed and the efficiency is shown by comparing analysis experimental results of full-scale test.
Hirota, Koichi; Kojima, Takuji
Bulletin of the Chemical Society of Japan, 78(9), p.1685 - 1690, 2005/09
Times Cited Count：7 Percentile：31.68(Chemistry, Multidisciplinary)Decomposition behavior under electron-beam irradiation was examined for polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) isomers in incinerator gases. Significant decomposition was obtained for all PCDD isomers over the investigated absorbed doses, which was resulted from oxidation reactions with OH radicals yielded by electron-beam irradiation. In the case of PCDFs, specific isomers having symmetrical structures such as 1, 2, 8, 9-, 2, 3, 7, 8-, and 3, 4, 6, 7-TeCDFs were yielded through the dechlorination of PeCDF isomers. Thermal electrons probably played a role in the dechlorination of PeCDF isomers.
Tsunogai, Shizuo*; Kawada, Kentaro*; Watanabe, Shuichi*; Aramaki, Takafumi
Journal of Oceanography, 59(5), p.685 - 693, 2003/10
Times Cited Count：28 Percentile：48.05(Oceanography)The water column distributions of CFC (chlorofluorocarbon) were determined twice in 2000 and 2001 in the northwestern Japan Sea. In 2000, the CFC-11 concentration decreased almost exponentially with depth from 6 pmol/kg at a few hundred m deep to 0.3 pmol/kg or less at the bottom of about 3400 m depth at 3 stations about 300 km off Vladivostok. In 2001, the CFC-11 concentration increased extremely up to 2 pmol/kg in the bottom water, while it did not increase at a station about 450 km away to the northeast. This is due to the renewal of the bottom water replaced by the surface water flowing down along the continental slope. The increase in the CFC-11 concentration was observed even in the whole water column above 3000 m depth. The increase in inventory is almost four times larger than that in the bottom water below 3000 m depth and equals about 1/6 of the total inventory found in 2000. The increase also means that 3 % of the deep water was replaced by the recent surface water or the turnover time of the deep water to be about 30 years, if the turnover occurs every year.
Oka, Kiyoshi
Reza Kenkyu, 31(9), p.612 - 617, 2003/09
no abstracts in English
Wan, C.*; Motohashi, Yoshinobu*; Shibata, Taiju; Baba, Shinichi; Ishihara, Masahiro; Hoshiya, Taiji
Journal of Iron and Steel Research, International, Special Issue IFAMST, p.85 - 89, 2002/06
no abstracts in English
Wan, C.*; Shibata, Taiju; Baba, Shinichi; Ishihara, Masahiro; Hoshiya, Taiji; Motohashi, Yoshinobu*
Netsu Bussei, 16(2), p.58 - 63, 2002/06
no abstracts in English
biological effectiveness of JRR-4 epithermal neutron beam; Experiment under free air beam and in water phantom (Cooperative research)Yamamoto, Tetsuya*; Yamamoto, Kazuyoshi; Matsumura, Akira*; Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Torii, Yoshiya; Horiguchi, Yoji; Nose, Tadao*
JAERI-Research 2002-011, 56 Pages, 2002/05
JAERI-Research-2002-011.pdf:3.17MB
The surviving curve and RBE of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at JRR-4. Surviving fraction of V79 cell with or without 
B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam(TNB-2), which were used or planned to use for clinical trial. The cell killing effect of these beams depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. RBE of the boron capture were 3.990.24, 3.040.19 and 1.430.08, RBE of the high-LET dose components based were 2.500.32, 2.340.30 and 2.170.28 for ENB, TNB-1 and TNB-2, respectively. The experimental determination of biological effectiveness factor outlined in this paper is applicable to the dose calculation for each dose component of the neutron beams and contribute to an accurate RBE as comparison with a neutron beam at a different facility employed in ongoing and planned BNCT clinical trials.
Nagase, Fumihisa; Otomo, Takashi; Uetsuka, Hiroshi
JAERI-Research 2001-009, 21 Pages, 2001/03
JAERI-Research-2001-009.pdf:2.93MB
no abstracts in English
Ishihara, Masahiro; Shibata, Taiju; Baba, Shinichi; Hoshiya, Taiji; Wan, C.*; Motohashi, Yoshinobu*
Proceedings of OECD/NEA 2nd Information Exchange Meeting on Basic Studies in the Field of High-temperature Engineering, p.113 - 124, 2001/00
no abstracts in English
Nishimura, Hideo
Kaku Busshitsu Kanri Senta Nyusu, 28(8), p.5 - 7, 1999/08
no abstracts in English
