Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 326

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

How different is the core of $$^{25}$$F from $$^{24}$$O$$_{g.s.}$$ ?

Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri. A.*; Hwang, S. H.*; et al.

Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05

 Times Cited Count:1 Percentile:100(Physics, Multidisciplinary)

The structure of a neutron-rich $$^{25}$$F nucleus is investigated by a quasifree ($$p,2p$$) knockout reaction. The sum of spectroscopic factors of $$pi 0d_{5/2}$$ orbital is found to be 1.0 $$pm$$ 0.3. The result shows that the $$^{24}$$O core of $$^{25}$$F nucleus significantly differs from a free $$^{24}$$O nucleus, and the core consists of $$sim$$35% $$^{24}$$O$$_{rm g.s.}$$, and $$sim$$65% excited $$^{24}$$O. The result shows that the $$^{24}$$O core of $$^{25}$$F nucleus significantly differs from a free $$^{24}$$O nucleus. The result may infer that the addition of the $$0d_{5/2}$$ proton considerably changes the neutron structure in $$^{25}$$F from that in $$^{24}$$O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

 Times Cited Count:4 Percentile:23.32(Physics, Multidisciplinary)

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for $$^{107}$$Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

Journal Articles

Absorbent property of fullerene for cesium isotope separation investigated using X-ray photoelectron spectroscopy

Sekiguchi, Tetsuhiro; Yokoyama, Keiichi; Uozumi, Yuki*; Yano, Masahiro; Asaoka, Hidehito; Suzuki, Shinichi; Yaita, Tsuyoshi

Progress in Nuclear Science and Technology (Internet), 5, p.161 - 164, 2018/11

For nuclear transmutation of cesium-135 ($$^{135}$$Cs), which is long-lived fission product, we are developing selective absorbent which takes only Cs atom in, but does not CsI. In this study, absorbing property of Cs atom onto the surface of fullerene (C$$_{60}$$) film has been investigated using synchrotron-based angle-dependent X-ray photoelectron spectroscopy (XPS). The results were compared with those of CsI. It was found that Cs penetrates into C$$_{60}$$ deep bulk. In contrast, CsI deposits on shallow surface. Furthermore, XPS spectra were measured as a function of Ar$$^{+}$$-sputtering time in order to know Cs concentration profiles in deep region. Results showed that Cs penetrates into deep region of several hundreds ${AA}$.

Journal Articles

Adsorption of platinum-group metals and molybdenum onto aluminum ferrocyanide in spent fuel solution

Onishi, Takashi; Sekioka, Ken*; Suto, Mitsuo*; Tanaka, Kosuke; Koyama, Shinichi; Inaba, Yusuke*; Takahashi, Hideharu*; Harigai, Miki*; Takeshita, Kenji*

Energy Procedia, 131, p.151 - 156, 2017/12

 Times Cited Count:4 Percentile:2.53

no abstracts in English

Journal Articles

Fabrication and short-term irradiation behaviour of Am-bearing MOX fuels

Kihara, Yoshiyuki; Tanaka, Kosuke; Koyama, Shinichi; Yoshimochi, Hiroshi; Seki, Takayuki; Katsuyama, Kozo

NEA/NSC/R(2017)3, p.341 - 350, 2017/11

In order to investigate the effect of the addition of americium to MOX fuels on the irradiation behaviour, the "Am-1" program is being conducted at the JAEA. The Am-1 program consists of two short-term irradiation tests of 10-min and 24-h irradiation periods, and a steady-state irradiation test. The short-term irradiation tests and their post irradiation examinations (PIEs) have been successfully completed. To date, the data for PIE of the Am-MOX fuels focused on the microstructural evolution and redistribution behaviour of Am at the initial stage of irradiation have been obtained and reported. In this paper, the results obtained from the Am-1 program are reviewed and detailed descriptions of the fabrication and inspection techniques for the Am-MOX fuels prepared for the program are provided. PIE data for the Am-MOX fuels at the initial stage of irradiation have been accumulated. In this paper, unpublished PIE data for the Am-MOX fuels are also presented.

Journal Articles

Effects of $$gamma$$ irradiation on the adsorption characteristics of xerogel microcapsules

Onishi, Takashi; Tanaka, Kosuke; Koyama, Shinichi; Ou, L. Y.*; Mimura, Hitoshi*

NEA/NSC/R(2017)3, p.463 - 469, 2017/11

no abstracts in English

Journal Articles

Outline of Japan Atomic Energy Agency's Okuma Analysis and Research Center, 2; Labolatory-1

Sugaya, Yuki; Sakazume, Yoshinori; Akutsu, Hideyuki; Inoue, Toshihiko; Yoshimochi, Hiroshi; Sato, Soichi; Koyama, Tomozo; Nakayama, Shinichi

Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 8 Pages, 2017/00

The Japan Atomic Energy Agency has been developing the research and development facilities, "Okuma Analysis and Research Center", in order to ascertain the properties of radioactive wastes and fuel debris towards the decommissioning of TEPCO's Fukushima Daiichi Nuclear Power Station. This paper outlines the concept of "Laboratory-1" which will analyze low and medium level samples in the Okuma Analysis and Research Center with a focus on the research plan.

Journal Articles

Outline of Japan Atomic Energy Agency's Okuma Analysis and Research Center, 3; Laboratory-2

Ito, Masayasu; Ogawa, Miho; Inoue, Toshihiko; Yoshimochi, Hiroshi; Koyama, Shinichi; Koyama, Tomozo; Nakayama, Shinichi

Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 7 Pages, 2017/00

Laboratory-2 of the Okuma Analysis and Research Center will be used for the technological development of techniques to treat and dispose fuel debris, etc. The specific analytical content and its importance has been discussed by an experts committee in FY 2016. The committee regarded fuel debris retrieval and criticality control related topics as the most important content. As a result, it will be a priority to introduce equipment to perform examination such as shape and size measurement, compositional and nuclide analysis, hardness and toughness test, and radiation dose rate measurement. In addition, since sample will have high dose rates (1 Sv/h or more) at the time of reception, hot cells with enough radiation shielding ability will be used. In the hot cell, the pre-processing will be performed, such as cutting and dissolution of samples. Processed samples will be examined in concrete cells, steel cells, glove boxes and fume hoods. Detail design of Laboratory-2 started on FY 2017.

Journal Articles

The Outline of Japan Atomic Energy Agency's Okuma Analysis and Research Center, 1; The Total progress of Labolatory-1 and Labolatory-2

Inoue, Toshihiko; Ogawa, Miho; Sakazume, Yoshinori; Yoshimochi, Hiroshi; Sato, Soichi; Koyama, Shinichi; Koyama, Tomozo; Nakayama, Shinichi

Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 7 Pages, 2017/00

Decommissioning of TEPCO's 1F is in progress according to the Roadmap. The Roadmap assigned the construction of a hot laboratory and analysis to the JAEA. The hot laboratory, Okuma Analysis and Research Center consists of the three buildings; Administrative building, the Laboratory-1 and Laboratory-2. The Laboratory-1 and Laboratory-2 are hot laboratories. Laboratory-1 is for radiometric analysis of low and medium level radioactive rubble and secondary wastes. The license of the Laboratory-1's implementation was approved by The Secretariat of the Nuclear Regulation Authority and the construction started in April 2017 and plans an operational start in 2020. Laboratory-2 provides concrete cells, steel cells for the analysis of the fuel debris and high level radioactive rubble. The Laboratory-2's major analysis items is reviewed by review meeting organized of cognoscente.

Journal Articles

Correlation effect in Sr$$_{1-x}$$La$$_x$$RuO$$_3$$ studied by soft X-ray photoemission spectroscopy

Kawasaki, Ikuto*; Sakon, Yumi*; Fujimori, Shinichi; Yamagami, Hiroshi; Tenya, Kenichi*; Yokoyama, Makoto*

Physical Review B, 94(17), p.174427_1 - 174427_7, 2016/11

 Times Cited Count:4 Percentile:68.29(Materials Science, Multidisciplinary)

Journal Articles

Early-in-life fuel restructuring behavior of Am-bearing MOX fuels

Tanaka, Kosuke; Sasaki, Shinji; Katsuyama, Kozo; Koyama, Shinichi

Transactions of the American Nuclear Society, 113(1), p.619 - 621, 2015/10

In order to evaluate the microstructural change behavior of Am-MOX fuels at the initial stage of irradiation, detailed investigations using image analysis were performed on X-ray Computed Tomography (X-ray CT) images and on ceramographs from fuels irradiated in both B11 and B14.

Journal Articles

Cesium sorption and desorption behavior of clay minerals

Yokoyama, Shingo*; Nakata, Kotaro*; Suzuki, Shinichi

Nendo Kagaku, 54(1), p.28 - 35, 2015/08

no abstracts in English

Journal Articles

Chemical form consideration of released fission products from irradiated fast reactor fuels during overheating

Sato, Isamu; Tanaka, Kosuke; Koyama, Shinichi; Matsushima, Kenichi*; Matsunaga, Junji*; Hirai, Mutsumi*; Endo, Hiroshi*; Haga, Kazuo*

Energy Procedia, 82, p.86 - 91, 2015/07

 Times Cited Count:2 Percentile:74.03(Nuclear Science & Technology)

Experiments simulating overheating conditions of fast reactor severe accidents have been previously carried out with irradiated fuels. For the present study, the chemical forms of the fission products (FPs) included in the irradiated fuels were evaluated by thermochemical equilibrium calculations. At temperatures of 2773 K and 2973 K, the most stable forms of Cs, I, Te, Sb, Pd and Ag are gaseous compounds. Cs and Sb detected in the thermal gradient tube (TGT) in the experiments can take gaseous chemical forms of elemental Cs, CsI, Cs$$_{2}$$MoO$$_{4}$$, CsO and elemental Sb, SbO, SbTe, respectively. By comparing experimental results and the estimations, it is seen CsI thermochemically behaves in a manner that traps it in the TGT, while elemental Cs trends to move as fine particles. The moving behavior of the gaseous FPs will obey not only thermochemical principles, but also those of particle dynamics.

Journal Articles

Removal of zirconium from spent fuel solution by alginate gel polymer

Onishi, Takashi; Koyama, Shinichi; Mimura, Hitoshi*

Progress in Nuclear Energy, 82, p.69 - 73, 2015/07

 Times Cited Count:4 Percentile:53.79(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Superdeformation in $$^{35}$$S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Kobayashi, Motoki*; Kisamori, Keiichi*; Takaki, Motonobu*; Miya, Hioyuki*; Ota, Shinsuke*; Michimasa, Shinichiro*; Shimoura, Susumu*; et al.

JPS Conference Proceedings (Internet), 6, p.030005_1 - 030005_4, 2015/06

Journal Articles

Influence of boron vapor on transport behavior of deposited CsI during heating test simulating a BWR severe accident condition

Sato, Isamu; Onishi, Takashi; Tanaka, Kosuke; Iwasaki, Maho; Koyama, Shinichi

Journal of Nuclear Materials, 461, p.22 - 28, 2015/06

We observed one of the simplified processes by conducting primitive experiments. CsI was heated at 1323 K to be vaporized and deposited on sampling parts with a temperature range of 1023 - 423 K and then B$$_{2}$$O$$_{3}$$ was vaporized at 1973 K to be reacted with Cs/I there. After heating tests, each sampling part was soaked into alkali water to dissolve the surface-deposits for ICP-MS analysis. The results showed that CsI deposited at the sampling parts kept above approx. 850 K was striped by B$$_{2}$$O$$_{3}$$ vapour. This behaviour will be thermodynamically discussed to study the Cs/I/B chemistry in the severe accidents.

Journal Articles

Influence of boron vapor on transport behavior of deposited CsI during heating test simulating a BWR severe accident condition

Sato, Isamu; Onishi, Takashi; Tanaka, Kosuke; Iwasaki, Maho; Koyama, Shinichi

Journal of Nuclear Materials, 461, p.22 - 28, 2015/06

 Times Cited Count:6 Percentile:38.87(Materials Science, Multidisciplinary)

In order to evaluate B influence on the release and transport of Cs and I during severe accidents, basic experiments have been performed on the interaction between deposited Cs/I compounds and vapor/aerosol B compounds. CsI and B$$_{2}$$O$$_{3}$$ were utilized as a Cs/I compound and a B compound, respectively. Deposited CsI on the thermal gradient tube (TGT), which is exposed to temperatures ranging from 423 K to 1023 K was reacted with vapor/aerosol B$$_{2}$$O$$_{3}$$, and then observed to determine how it changed Cs/I decomposition profiles. As a result, vapor/aerosol B$$_{2}$$O$$_{3}$$ stripped a portion of deposited CsI within a temperature range from 830 K to 920 K to make gaseous CsBO$$_{2}$$ and I$$_{2}$$. In addition, gaseous I$$_{2}$$ was re-deposited at a temperature range from 530 K to 740 K, while CsBO$$_{2}$$ travelled through the sampling tubes and filters without deposition. It is implied that B influences Cs carriers such as CsBO$$_{2}$$ to transport Cs to the colder regions.

Journal Articles

Oxidation behavior of Am-containing MOX fuel pellets in air

Tanaka, Kosuke; Yoshimochi, Hiroshi; Obayashi, Hiroshi; Koyama, Shinichi

Energy Procedia, 71, p.282 - 292, 2015/05

 Times Cited Count:2 Percentile:9.34

Americium-containing MOX (Am-MOX) fuels were subjected to heating tests using thermogravimetric and differential thermal analysis (TG-DTA) measurements in a flowing gas atmosphere of dry air to investigate the effect of Am addition on oxidation behavior of MOX fuel.

Journal Articles

Penetration behavior of water solution containing radioactive species into dried concrete/mortar and epoxy resin materials

Sato, Isamu; Maeda, Koji; Suto, Mitsuo; Osaka, Masahiko; Usuki, Toshiyuki; Koyama, Shinichi

Journal of Nuclear Science and Technology, 52(4), p.580 - 587, 2015/04

 Times Cited Count:5 Percentile:45.73(Nuclear Science & Technology)

Penetration behavior of radionuclides such as $$^{137}$$Cs into dried concrete material, dried mortar material and epoxy paint for a few dozen days was observed using a solution containing fission products extracted from irradiated fuels to obtain fundamental information on the radionuclide penetration rate and depth. Hardly any radionuclides could penetrate into the epoxy paint. The radionuclide solution penetrated into concrete and mortar materials to a depth of a few millimeters for a few dozen days. The penetration behavior observed near the surface of concrete and mortar materials was similar to the diffusion of nuclides in media such as water-saturated concrete, bentonite and cement materials.

Journal Articles

Mesoscopic structures of vermiculite and weathered biotite clays in suspension with and without cesium ions

Motokawa, Ryuhei; Endo, Hitoshi*; Yokoyama, Shingo*; Ogawa, Hiroki*; Kobayashi, Toru; Suzuki, Shinichi; Yaita, Tsuyoshi

Langmuir, 30(50), p.15127 - 15134, 2014/12

 Times Cited Count:17 Percentile:41.76(Chemistry, Multidisciplinary)

326 (Records 1-20 displayed on this page)