Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Watakabe, Tomoyoshi; Takahashi, Hideki*
Journal of Pressure Vessel Technology, 145(5), p.051502_1 - 051502_11, 2023/10
Times Cited Count：0 Percentile：0(Engineering, Mechanical)To ensure the seismic integrity of Sodium Cooled Fast Reactors, both confirming the ultimate strength under a high-level earthquake beyond the design condition and clarifying the design safety margin up to ultimate strength have been focused as important issues. In this study, a series of dynamic failure tests of a thin wall tee for Sodium-Cooled Fast Reactors was conducted. Some discussions related to the thin wall tee are provided on the failure mode under seismic load, dynamic response behavior, accuracy of fatigue prediction by dynamic elastic-plastic analysis, and a safety margin of fatigue evaluation which is included in conventional design rule.
Okuda, Takahiro; Takahashi, Hideki*; Watakabe, Tomoyoshi
Mechanical Engineering Journal (Internet), 10(4), p.23-00075_1 - 23-00075_9, 2023/08
In recent years, to make the seismic design more rational for the piping systems in nuclear power plants, it has been expected to develop a design method considering plastic deformation and the accompanying energy dissipation of the piping itself. In this study, an extensive series of seismic response analyses was conducted to investigate the degree of influence of the plastic deformation of the pipe support structures on the seismic response of the entire piping system. The analyses include; plasticity is considered for (1) none, (2) the piping only, (3) the support structure only, and (4) both the piping and the support structure.
-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：90.12(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.
Cs activity concentration in the aquatic insect 
(Tricoptera: Stenopsychidae) in the Ota River, Fukushima, JapanIshii, Yumiko*; Miura, Hikaru*; Jo, J.*; Tsuji, Hideki*; Saito, Rie; Koarai, Kazuma; Hagiwara, Hiroki; Urushidate, Tadayuki*; Nishikiori, Tatsuhiro*; Wada, Toshihiro*; et al.
PLOS ONE (Internet), 17(5), p.e0268629_1 - e0268629_17, 2022/05
Times Cited Count：3 Percentile：43.07(Multidisciplinary Sciences)We investigated the variability in Cs activity concentration in individual aquatic insects in detritivorous caddisfly () and carnivorous dobsonfly (
) larvae from the Ota River, Fukushima. Caddisfly larvae showed sporadically higher radioactivity, whereas no such outliers were observed in dobsonfly larvae. Autoradiography and scanning electron microscopy analyses confirmed that these caddisfly larvae samples contained radiocesium-bearing microparticles (CsMPs), which are insoluble Cs-bearing silicate glass particles. CsMPs were also found in potential food sources of caddisfly larvae, such as periphyton and drifting particulate organic matter, indicating that larvae may ingest CsMPs along with food particles of similar size. Although CsMPs distribution and uptake by organisms in freshwater ecosystems is relatively unknown, our study demonstrates that CsMPs can be taken up by aquatic insects.
Nakasone, Shunya*; Yokoyama, Sumi*; Takahashi, Tomoyuki*; Ota, Masakazu; Kakiuchi, Hideki*; Sugihara, Shinji*; Hirao, Shigekazu*; Momoshima, Noriyuki*; Tamari, Toshiya*; Shima, Nagayoshi*; et al.
Plasma and Fusion Research (Internet), 16, p.2405035_1 - 2405035_5, 2021/02
Removal of impurities such as organic and other types of dissolved matters from environmental water samples is required for precise analysis of tritium with a liquid scintillation counting method. In general, a distillation method is a conventional one for tritium analysis in environmental water samples, but is a time-consuming process that takes 24 hours for removal of impurities. We have proposed a rapid pretreatment method for tritium analysis, that uses ion exchange resins. In this study, we performed batch experiments, to evaluate the effectiveness of the ion exchange resins on the tritium measurement. The results obtained demonstrated that removal of impurities in the sample water by ion exchange resins can be achieved during a short period of time (i.e., in 5 min).
Takahashi, Yutaka*; Mikoshiba, Masumi*; Shimura, Toshiaki*; Nagata, Mitsuhiro; Iwano, Hideki*; Danhara, Toru*; Hirata, Takafumi*
Island Arc, 30(1), p.e12393_1 - e12393_15, 2021/01
Times Cited Count：2 Percentile：17.26(Geosciences, Multidisciplinary)The Hidaka metamorphic belt is an excellent example of island-arc-type crust, and in this belt the metamorphic grade increases westwards from unmetamorphosed sediment up to the granulite facies. The metamorphic age of the belt had previously been considered to be ca. 55 Ma. However, zircons from the granulites in the lower sequence have given U-Pb ages of ca. 21-19 Ma and a preliminary report on zircons from pelitic gneiss in the upper sequence gave a U-Pb age of ca. 40 Ma. In this paper we provide new U-Pb ages for zircons from the pelitic gneisses in the upper sequence in order to assess the metamorphic age and also the maximum depositional age of the sedimentary protolith. The weighted mean 
Pb/
U ages and 2 sigma errors for zircons from biotite gneiss in the central area of the belt are 39.6 
0.9 Ma for metamorphic overgrowth rims and 53.1 0.9 Ma for the youngest inherited detrital cores. The ages of zircons from cordierite-biotite gneiss in the southern area are 35.9 0.7 Ma for overgrowth rims and 46.5 2.8 Ma for the youngest detrital cores. These results indicate that the metamorphism of the upper sequence took place at ca. 40-36 Ma, and that the sedimentary protolith was deposited after ca. 53-47 Ma. These metamorphic ages are consistent with the reported ages of ca. 37-36 Ma plutonic rocks in the upper sequence, but contrast with the ca. 21-19 Ma ages of metamorphic and plutonic rocks in the lower sequence. Therefore, we conclude, that the upper and lower metamorphic sequences developed independently but became coupled before ca. 19 Ma as a result of dextral reverse tectonic movements, as indicated by the intrusion of ca. 19-18 Ma magmas, possibly generated in the lower sequence, into the upper sequence.
Nakasone, Shunya*; Yokoyama, Sumi*; Takahashi, Tomoyuki*; Ota, Masakazu; Kakiuchi, Hideki*; Sugihara, Shinji*; Hirao, Shigekazu*; Momoshima, Noriyuki*; Tamari, Toshiya*; Shima, Nagayoshi*; et al.
Plasma and Fusion Research (Internet), 15, p.2405027_1 - 2405027_3, 2020/05
A quick preprocessing system for tritium analysis of environmental samples is important to judge environmental influence of tritium releases due to accident or tritium-handling facilities. Analysis of tritium in water samples with liquid scintillation counting method requires removal of impurities such as organic matter and ion species from water samples. Generally, a distillation method is adopted as a pretreatment of analysis for tritium; however, the distillation method is a time-consuming process. The aim of this study is to evaluate a rapid pretreatment method for tritium analysis with ion exchange resin. From batch and column experiments that used inland water and ion exchange resin, we confirmed removals of impurities of the water sample and that the removal of impurities was possible for a short time (by 5 minutes).
Yokoyama, Sumi*; Takahashi, Tomoyuki*; Ota, Masakazu; Kakiuchi, Hideki*; Sugihara, Shinji*; Hirao, Shigekazu*; Momoshima, Noriyuki*; Tamari, Toshiya*; Shima, Nagayoshi*; Atarashi-Andoh, Mariko; et al.
Plasma and Fusion Research (Internet), 14(Sp.2), p.3405099_1 - 3405099_4, 2019/06
The Large Helical Device of the National Institute for Fusion Science started D-D experiments in 2017. To ensure the safety of the facility, it is important to develop evaluation methods for environmental tritium transfer. Tritiated water (HTO) in atmosphere and soil is transferred to plants, and organically bound tritium (OBT) is formed by photosynthesis. Prediction of OBT formation is important, because OBT accumulates in plants and causes dose through ingestion. The objective of this study is to estimate environmental tritium transfer using a simple compartment model and practical parameters. We proposed a simple compartment model consisting of air-soil-plant components, and tried to validate the model by comparison with a sophisticated model, SOLVEG. In this study, we plan to add wet deposition to the model and obtain parameters from measurements of soil permeability and tritium concentrations in air, soil and plants. We also establish rapid pretreatment methods for OBT analysis.
Cl in soil near the Fukushima Dai-ichi Nuclear Power PlantOta, Yuki*; Sueki, Keisuke*; Sasa, Kimikazu*; Takahashi, Tsutomu*; Matsunaka, Tetsuya*; Matsumura, Masumi*; Tosaki, Yuki*; Honda, Maki*; Hosoya, Seiji*; Takano, Kenta*; et al.
JAEA-Conf 2018-002, p.99 - 102, 2019/02
no abstracts in English
Sn cable assembled with conduit for ITER central solenoidNabara, Yoshihiro; Suwa, Tomone; Takahashi, Yoshikazu; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200305_1 - 4200305_5, 2015/06
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)
Sn conductors for toroidal field coils in ITERNabara, Yoshihiro; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Suwa, Tomone; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.6000605_1 - 6000605_5, 2014/06
Times Cited Count：7 Percentile：39.51(Engineering, Electrical & Electronic)no abstracts in English
Hemmi, Tsutomu; Harjo, S.; Kajitani, Hideki; Nabara, Yoshihiro; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Koizumi, Norikiyo; Abe, Jun; Gong, W.; Aizawa, Kazuya; et al.
KEK Progress Report 2013-4, p.45 - 47, 2013/11
The gradual degradation was observed in the results for ITER CS conductor samples. To investigate its origin, the internal strain in the sample after the testing was successfully measured using a neutron diffraction technique non-destructively. Up to now, the transverse electromagnetic loading has been considered as an origin of the degradation due to the local bending at the high loading side (HLS). However, as a result of the neutron diffraction measurement, the large bending at the LLS of the HFZ was found. The large bending was considered as an origin of the strand buckling due to the large void generated by the transverse electromagnetic loading and the thermally induced residual compressive strain. For the improvement of the conductor performance on the strand buckling, the shorter twisting pitch (STP) can be considered. The result of the SULTAN testing of the conductor sample with STP found very effective, and the performance degradation was negligible.
Nagao, Seiya*; Niibori, Yuichi*; Tanaka, Tadao; Sasaki, Takayuki*; Saito, Takumi*; Kirishima, Akira*; Yoshikawa, Hideki; Iijima, Kazuki; Hama, Katsuhiro; Iwatsuki, Teruki; et al.
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 20(1), p.3 - 14, 2013/06
This paper shows a current status of groundwater colloids studies on the performance assessment of geological disposal of radioactive wastes in Japan, and summaries realistic approach of the colloids studies at a substantial research network for Japanese universities and institutes.
Sn conductors for ITER central solenoidsNabara, Yoshihiro; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Takahashi, Yoshikazu; Matsui, Kunihiro; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 23(3), p.4801604_1 - 4801604_4, 2013/06
Times Cited Count：10 Percentile：48(Engineering, Electrical & Electronic)no abstracts in English
Minami, Ryutaro*; Kariya, Tsuyoshi*; Imai, Tsuyoshi*; Numakura, Tomoharu*; Endo, Yoichi*; Nakabayashi, Hidetaka*; Eguchi, Taku*; Shimozuma, Takashi*; Kubo, Shin*; Yoshimura, Yasuo*; et al.
Nuclear Fusion, 53(6), p.063003_1 - 063003_7, 2013/06
Minami, Ryutaro*; Kariya, Tsuyoshi*; Imai, Tsuyoshi*; Numakura, Tomoharu*; Endo, Yoichi*; Nakabayashi, Hidetaka*; Eguchi, Taku*; Shimozuma, Takashi*; Kubo, Shin*; Yoshimura, Yasuo*; et al.
Nuclear Fusion, 53(6), p.063003_1 - 063003_7, 2013/06
Times Cited Count：12 Percentile：47.42(Physics, Fluids & Plasmas)Hemmi, Tsutomu; Nunoya, Yoshihiko; Nabara, Yoshihiro; Yoshikawa, Masatoshi*; Matsui, Kunihiro; Kajitani, Hideki; Hamada, Kazuya; Isono, Takaaki; Takahashi, Yoshikazu; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4803305_1 - 4803305_5, 2012/06
Times Cited Count：45 Percentile：85.83(Engineering, Electrical & Electronic)To characterize the performance of the CS conductor, a CS conductor sample was tested in the SULTAN facility at CRPP. As a result of the cyclic test up to 1000 cycles, measured Tcs was in good agreement with the expected Tcs, which is calculated by the characteristics of the NbSn strands and the designed strain. However, continuous degradation of Tcs was observed after 1000 cycles. The degradation of Tcs was around 0.6 K from 1000 cycles to 6000 cycles. On the other hand, the degradation of Tcs by cyclic operation is nearly 0.1 K from 1000 cycles to 10,000 cycles in the CS Insert test at JAEA in 2000. To investigate the causes for the degradation of Tcs, the following items are performed; (1) strain measurement by neutron diffraction, (2) strain measurement by sample cuttings, (3) strand position observation, (4) visual inspection on strands, (5) filament breakage observation, (6) modeling and calculation of the degradation. Detailed results will be presented and discussed.
Sn conductors for ITER toroidal field coilsNabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Takahashi, Yoshikazu; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Ebisawa, Noboru; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4804804_1 - 4804804_4, 2012/06
Times Cited Count：18 Percentile：65.46(Engineering, Electrical & Electronic)no abstracts in English
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.
Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01
Times Cited Count：52 Percentile：71.25(Biochemistry & Molecular Biology)Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.
