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Journal Articles

A Knowledge-sharing activity on the environmental radiation monitoring results affected by the Fukushima-Daiichi Nuclear Power Plant Accident at Tokai-Oarai area in Ibaraki Prefecture

Nakano, Masanao; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Okura, Takehisa; Kuramochi, Akihiko; Kawasaki, Masatsugu; Takeuchi, Erina; Fujii, Yutaka*; Jinno, Tsukasa*; et al.

Hoken Butsuri (Internet), 55(2), p.102 - 109, 2020/06

After the Fukushima-Daiichi Nuclear Power Station (1F) Accident in March 2011, the increase was significantly observed in a part of the result of the environmental radiation monitoring in Ibaraki prefecture. "The review meeting of the environmental effect from 1F accident" was established to discuss technically the fluctuation of monitoring data. The review meeting collected the monitoring data from the four nuclear operators, and discussed a fluctuating trend, $$^{134}$$Cs/$$^{137}$$Cs activity ratio, and so on. In this report, the results of the dose rate and $$^{137}$$Cs in fallout, surface soil, flatfish and seabed sediment are introduced. Also the problem solving in the review meeting is introduced.

Journal Articles

$$omega N$$ scattering length from $$omega$$ photoproduction on the proton near the reaction threshold

Ishikawa, Takatsugu*; Fujimura, Hisako*; Fukasawa, Hiroshi*; Hashimoto, Ryo*; He, Q.*; Honda, Yuki*; Hosaka, Atsushi; Iwata, Takahiro*; Kaida, Shun*; Kasagi, Jirota*; et al.

Physical Review C, 101(5), p.052201_1 - 052201_6, 2020/05

 Times Cited Count:4 Percentile:45.12(Physics, Nuclear)

Journal Articles

Development of numerical analysis method for core thermal-hydraulics during natural circulation decay heat removal in SFR, 1; Validation of ASFRE code in estimation of radial heat transfer phenomena

Kikuchi, Norihiro; Doda, Norihiro; Hashimoto, Akihiko*; Yoshikawa, Ryuji; Tanaka, Masaaki; Ohshima, Hiroyuki

Dai-23-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (USB Flash Drive), 5 Pages, 2018/06

For the thermal-hydraulic design regarding a fuel assembly of sodium-cooled fast reactors, a subchannel analysis code ASFRE has been developed by JAEA. ASFRE was applied to numerical simulations of several kinds of water and sodium experiments as its validation studies and it was confirmed that pressure drops and temperature distributions measured in the experiments can be well reproduced. To enhance safety of sodium-cooled fast reactor, it is required to evaluate thermal-hydraulics in a core during decay heat removal by natural circulation. It is necessary to estimate radial heat transfer phenomena between fuel assemblies. In this study, a numerical simulation of a 37-pin bundle sodium experiment with radial heat flux was carried out and it was confirmed that ASFRE can be qualitatively reproduced temperature distributions in a fuel assembly affected by radial heat transfer.

Journal Articles

Production of iodine radionuclides using $$^{7}$$Li ion beams

Nishinaka, Ichiro*; Yokoyama, Akihiko*; Washiyama, Koshin*; Makii, Hiroyuki; Hashimoto, Kazuyuki*

Journal of Radioanalytical and Nuclear Chemistry, 314(3), p.1947 - 1965, 2017/12

 Times Cited Count:2 Percentile:19.65(Chemistry, Analytical)

Production cross sections of iodine, tellurium and antimony radionuclides in the 24-59 MeV $$^{7}$$Li + $$^{nat}$$Sn reaction have been measured by the conventional stacked foil technique with $$gamma$$-ray spectrometry. Excitation functions of the production cross sections were compared with a statistical model calculation. The contributions of complete and incomplete fusion in the production of observed radionuclides are discussed from the view points of production routes in the nuclide chart and decays for iodine, tellurium and antimony nuclides. The integral yields of $$^{123,124,125,126}$$I were deduced from the calculated excitation functions in the $$^{7}$$Li induced reactions on Sn isotopes in view of the production of medically important $$^{123,124}$$I. The results are discussed by comparing with literature values in the other reactions.

Journal Articles

Development of thermal hydraulics analysis code ASFRE for fuel assembly of sodium-cooled fast reactor; Modification of distributed resistance model and validation analysis

Kikuchi, Norihiro; Ohshima, Hiroyuki; Tanaka, Masaaki; Hashimoto, Akihiko*

Dai-21-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (USB Flash Drive), 4 Pages, 2016/06

For the thermal-hydraulic design and safety assessment regarding a fuel assembly of sodium-cooled fast reactors, a subchannel analysis code ASFRE has been and is continuously developed in JAEA. In the numerical simulation of ASFRE confirmed that the tendency to overestimate the maximum coolant temperature in a fuel assembly still remains. In this study, Distributed Resistance Model (DRM), which deals with wire-spacer wrap volumetric effect in subchannels on peripheral and axial directions, was modified and its calibration factor was optimized in order to improve the prediction accuracy of the maximum coolant temperature. A numerical simulation of a 37-pin bundle sodium experiment was also carried out and the result showed the validity of the modified DRM.

Journal Articles

Development of numerical simulation system for thermal-hydraulic analysis in fuel assembly of sodium-cooled fast reactor

Ohshima, Hiroyuki; Uwaba, Tomoyuki; Hashimoto, Akihiko*; Imai, Yasutomo*; Ito, Masahiro*

AIP Conference Proceedings 1702, p.040011_1 - 040011_4, 2015/12

A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies of sodium-cooled fast reactors under various operating conditions including fuel deformation. This paper gives a summary of numerical methods of component programs of the system and their validation studies.

Journal Articles

Production and separation of astatine isotopes in the $$^7$$Li + $$^{nat}$$Pb reaction

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Maeda, Eita*; Watanabe, Shigeki; Hashimoto, Kazuyuki; Ishioka, Noriko; Makii, Hiroyuki; Toyoshima, Atsushi; Yamada, Norihiro*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 304(3), p.1077 - 1083, 2015/06

 Times Cited Count:9 Percentile:60.64(Chemistry, Analytical)

Production cross sections of astatine isotopes $$^{207-211}$$At in the 29-57 MeV $$^7$$Li induced reaction with $$^{nat}$$Pb target have been measured by $$alpha$$- and $$gamma$$-ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of $$^7$$Li + $$^{nat}$$Pb. Considerably small experimental cross sections of $$^{210}$$At and $$^{209}$$At compared with the calculation were clearly observed at incident energies higher than 44 MeV, indicating that the effects of breakup reaction play a role. A chemical separation of astatine from an irradiated lead target has been studied with a dry-distillation method. A complementary way to produce astatine isotopes has been developed.

Journal Articles

The Possible interplanetary transfer of microbes; Assessing the viability of ${it Deinococcus}$ spp. under the ISS environmental conditions for performing exposure experiments of microbes in the Tanpopo mission

Kawaguchi, Yuko*; Yang, Y.*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Takasu, Masako*; Narumi, Issey*; Sato, Katsuya; Hashimoto, Hirofumi*; Nakagawa, Kazumichi*; Tanigawa, Yoshiaki*; et al.

Origins of Life and Evolution of Biospheres, 43(4-5), p.411 - 428, 2013/10

 Times Cited Count:41 Percentile:80.34(Biology)

Journal Articles

Tilted-foil technique for producing a spin-polarized radioactive isotope beam

Hirayama, Yoshikazu*; Mihara, Mototsugu*; Watanabe, Yutaka*; Jeong, S. C.*; Miyatake, Hiroari*; Momota, Sadao*; Hashimoto, Takashi*; Imai, Nobuaki*; Matsuta, Kensaku*; Ishiyama, Hironobu*; et al.

European Physical Journal A, 48(5), p.54_1 - 54_10, 2012/05

 Times Cited Count:2 Percentile:16.82(Physics, Nuclear)

Journal Articles

Super ODS steels R&D for fuel cladding of next generation nuclear systems, 2; Effect of minor alloying elements

Onuki, Somei*; Hashimoto, Naoyuki*; Ukai, Shigeharu*; Kimura, Akihiko*; Inoue, Masaki; Kaito, Takeji; Fujisawa, Toshiharu*; Okuda, Takanari*; Abe, Fujio*

Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9306_1 - 9306_5, 2009/05

For development of advanced ferritic ODS steels including high concentration of Cr and Al, the effect of minor alloying elements on fine dispersion of oxide particle was investigated. Microstructural analysis for Fe-16Cr-4Al-mY$$_{2}$$O$$_{3}$$-nZr or mHf due to TEM indicated that 0.3Zr or 0.6Hf are the optimum concentration. The mechanism of nano-sized oxide formation was also discussed.

Journal Articles

Super ODS steels R&D for fuel cladding of next generation nuclear systems, 9; Damage structure evolution under electron-irradiation

Onuki, Somei*; Hashimoto, Naoyuki*; Ukai, Shigeharu*; Kimura, Akihiko*; Inoue, Masaki; Kaito, Takeji; Fujisawa, Toshiharu*; Okuda, Takanari*; Abe, Fujio*

Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9307_1 - 9307_4, 2009/05

The aim of this study is to survey microstructural properties and irradiation response of advanced high Cr and Al ODS steels. The effects of minor element addition and heat-treatment are also investigated. In these steels, black dots-like dislocation loops were formed around oxide particles during electron irradiation, and then the behavior depended on the type of additional elements, but the irradiation resistance was confirmed generally. The irradiation response was not sensitive as the heat-treatment, but the minor element addition (Zr and Hf) showed an intensive suppressing the loop growth. The results suggest that a large number of oxides enhanced the mutual recombination of the irradiation-induced point defects, especially at their surface.

Journal Articles

A New measurement of the astrophysical $$^8$$Li(d,t)$$^7$$Li reaction

Hashimoto, Takashi; Ishiyama, Hironobu*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari; Jeong, S.-C.*; Tanaka, Masahiko*; Yoshikawa, Nobuharu*; Nomura, Toru*; et al.

Physics Letters B, 674(4-5), p.276 - 280, 2009/04

 Times Cited Count:7 Percentile:47.15(Astronomy & Astrophysics)

The excitation function of the $$^8$$Li(d,t)$$^7$$Li reaction was directly measured using $$^8$$Li beams at E$$_{mathrm{cm}}$$ = 0.3, 0.4, 0.5, 0.7, 0.8, 1.0, 1.1, and 1.2 MeV with CD$$_2$$ targets. The beam energies covered the Gamow peaks for 1$$sim$$3$$times$$10$$^9$$ K. Large cross sections were observed at around E$$_{mathrm{cm}}$$ = 0.8 MeV, implying a resonance state located at 22.4 MeV in $$^{10}$$Be. The present astrophysical reaction rate is higher in one order magnitude than the presently adopted rate at around 1$$times$$10$$^9$$ K.

Journal Articles

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution

Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.

Radiochimica Acta, 97(2), p.83 - 89, 2009/02

 Times Cited Count:20 Percentile:77.78(Chemistry, Inorganic & Nuclear)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F, 5n)$$^{262}$$Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K$$_{d}$$) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta $$approx$$ Nb $$>$$ Db $$geq$$ Pa.

Journal Articles

Diffusion of $$^{8}$$Li short-lived radiotracer in Li ionic conductors of NaTl-type intermetallic compounds

Sugai, Hiroyuki; Sataka, Masao; Okayasu, Satoru; Ichikawa, Shinichi; Nishio, Katsuhisa; Mitsuoka, Shinichi; Nakanoya, Takamitsu; Osa, Akihiko; Sato, Tetsuya; Hashimoto, Takashi; et al.

Defect and Diffusion Forum, 273-276, p.667 - 672, 2008/00

Journal Articles

Present status of JAEA-Tokai tandem accelerator

Matsuda, Makoto; Takeuchi, Suehiro; Tsukihashi, Yoshihiro; Hanashima, Susumu; Abe, Shinichi; Osa, Akihiko; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; et al.

Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan, p.275 - 277, 2006/00

no abstracts in English

Journal Articles

Real-time [$$^{11}$$C]methionine translocation in barley in relation to mugineic acid phytosiderophore biosynthesis

Bughio, N.*; Nakanishi, Hiromi*; Kiyomiya, Shoichiro*; Matsuhashi, Shimpei; Ishioka, Noriko; Watanabe, Satoshi; Uchida, Hiroshi*; Tsuji, Atsunori*; Osa, Akihiko; Kume, Tamikazu; et al.

Planta, 213(5), p.708 - 715, 2001/09

 Times Cited Count:16 Percentile:36.85(Plant Sciences)

[$$^{11}$$C]Methionine ([$$^{11}$$C]Met) was supplied through barley roots and the $$^{11}$$C signal was follwoed using a real-time imaging system (PETIS), with subsequent development of autoradiographic images of the whole plant. In all cases, [$$^{11}$$C]Met was first translocated to the discrimination center, and this part was strongly labeled. Met absorbed by roots of the plants was subsequently translocated to other parts of the plant. In Fe-deficient (-Fe) barley plants, a drastic reduction in [$$^{11}$$C]Met translocation from the roots to the shoot was observed, while a greater amount of $$^{11}$$C was found in the leaves of Fe-sufficient or Met-pretreated -Fe plants. Treatment of -Fe plants with amiooxyacetic acid increased the translocation of [$$^{11}$$C]Met to the shoot. The retention of exogenously supplied [$$^{11}$$C]Met in the roots of -Fe barley indicates that the Met is used in the biosynthesis of mugineic acid (MA) in barley roots. This and the absence of Met movement from shoots to the roots suggest that the MA phytosiderophores precursor Met originates in the roots of plants.

Journal Articles

Vanadium uptake and an effect of vanadium treatment on $$^{18}$$F-labeled water movement in a cowpea plant by positron emitting tracer imaging system (PETIS)

Furukawa, Jun*; Yokota, Harumi*; Tanoi, Keitaro*; Ueoka, Shiori*; Matsuhashi, Shimpei; Ishioka, Noriko; Watanabe, Satoshi; Uchida, Hiroshi*; Tsuji, Atsunori*; Ito, Takehito*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 249(2), p.495 - 498, 2001/08

 Times Cited Count:16 Percentile:73.21(Chemistry, Analytical)

We present real time Vanadate (V$$^{5+}$$) uptake imaging in a cowpea plant by Positron Emitting Tracer Imaging System (PETIS). Vanadium-48 was produced by bombarding a Sc foil target with 50 MeV $$alpha$$-particles at Takasaki Ion accelerators for Advanced Radiation Application (TIARA) AVF cyclotron. Then $$^{48}$$V was added to the culture solution to investigate the V distribution in a cowpea plant. The real time uptake of the $$^{48}$$V was monitored by PETIS. We measured the distribution of $$^{48}$$V in a whole plant after 3, 6 and 20 hours of V treatment by Bio-imaging Analyzer System (BAS). After the 20 hour treatment, vanadate was detected at the up-ground part of the plant. To know the effect of V uptake on plant activity, $$^{18}$$F-labeled water uptake was analyzed by PETIS. When a cowpea plant was treated with V for 20 hours before $$^{18}$$F-labeled water uptake experiment, the total amount of $$^{18}$$F-labeled water absorption was drastically desreased. Results suggest the inhibition of water uptake was mainly caused by the vanadate already moved to the up-ground part of the plant.

Journal Articles

Visualization of $$^{15}$$O-water flow in tomato and rice in the light and dark using a positron-emitting tracer imaging system (PETIS)

Mori, Satoshi*; Kiyomiya, Shoichiro*; Nakanishi, Hiromi*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Matsuhashi, Shimpei; Hashimoto, Shoji; Sekine, Toshiaki; Uchida, Hiroshi*; et al.

Soil Science and Plant Nutrition, 46(4), p.975 - 979, 2000/12

 Times Cited Count:29 Percentile:57.37(Plant Sciences)

no abstracts in English

Journal Articles

Tantalum-183: Cyclotron production of a neutron-rich biomedical tracer

; R.M.Lambrecht*; Matsuoka, Hiromitsu; Osa, Akihiko; Koizumi, Mitsuo; Kobayashi, Katsutoshi; Izumo, Mishiroku; Hashimoto, Kazuyuki; Sekine, Toshiaki

Applied Radiation and Isotopes, 47(2), p.171 - 174, 1996/00

 Times Cited Count:4 Percentile:39.42(Chemistry, Inorganic & Nuclear)

no abstracts in English

Journal Articles

Production method of no-carrier-added $$^{186}$$Re

; Matsuoka, Hiromitsu; Osa, Akihiko; Koizumi, Mitsuo; Izumo, Mishiroku; Kobayashi, Katsutoshi; Hashimoto, Kazuyuki; Sekine, Toshiaki; R.M.Lambrecht*

Journal of Radioanalytical and Nuclear Chemistry, 205(1), p.85 - 92, 1996/00

 Times Cited Count:46 Percentile:95.16(Chemistry, Analytical)

no abstracts in English

66 (Records 1-20 displayed on this page)