Evaluation of the remaining spent extraction solvent in vermiculite after leaching tests via PIXE analysis

Arai, Yoichi; Watanabe, So; Hasegawa, Kenta; Okamura, Nobuo; Watanabe, Masayuki; Takeda, Keisuke*; Fukumoto, Hiroki*; Ago, Tomohiro*; Hagura, Naoto*; Tsukahara, Takehiko*

Nuclear Instruments and Methods in Physics Research B, 542, p.206 - 213, 2023/09

https://doi.org/10.1016/j.nimb.2023.07.003

The Chemistry of uranium (II); Method and practice

Sato, Nobuaki*; Kirishima, Akira*; Watanabe, Masayuki; Sasaki, Takayuki*; Uehara, Akihiro*; Takeda, Shino*

Uran No Kagaku (II); Hoho To Jissen, 143 Pages, 2021/03

This book describes necessary facts when readers would have an opportunity to treat Uranium for experiments. In the content, the method section shows experimental facilities and equipment including method, and the practical section mentions solution and solid state experiments using Uranium and/or radioisotopes.

Spallation and fragmentation cross sections for 168 MeV/nucleon Xe ions on proton, deuteron, and carbon targets

Sun, X. H.*; Wang, H.*; Otsu, Hideaki*; Sakurai, Hiroyoshi*; Ahn, D. S.*; Aikawa, Masayuki*; Fukuda, Naoki*; Isobe, Tadaaki*; Kawakami, Shunsuke*; Koyama, Shumpei*; et al.

Physical Review C, 101(6), p.064623_1 - 064623_12, 2020/06

https://doi.org/10.1103/PhysRevC.101.064623

The spallation and fragmentation reactions of Xe induced by proton, deuteron and carbon at 168 MeV/nucleon were studied at RIKEN Radioactive Isotope Beam Factory via the inverse kinematics technique. The cross sections of the lighter products are larger in the carbon-induced reactions due to the higher total kinetic energy of carbon. The energy dependence was investigated by comparing the newly obtained data with previous results obtained at higher reaction energies. The experimental data were compared with the results of SPACS, EPAX, PHITS and DEURACS calculations. These data serve as benchmarks for the model calculations.

Development of a fast reactor for minor actinides transmutation, 1; Overview and method development

Takeda, Toshikazu*; Usami, Shin; Fujimura, Koji*; Takakuwa, Masayuki*

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.560 - 566, 2015/09

The Ministry of Education, Culture, Sports, Science and Technology in Japan has launched a national project entitled "technology development for the environmental burden reduction" in 2013. The present study is one of the studies adopted as the national project. The objective of the study is the efficient and safe transmutation and volume reduction of minor actinides with long-lived radioactivity and high decay heat contained in high level radioactive wastes by using sodium cooled fast reactors. We are developing MA transmutation core concepts which harmonize efficient MA transmutation with core safety. To accurately design the core concepts we have improved calculation methods for estimating the transmutation rate of individual MA nuclides, and estimating and reducing uncertainty of MA transmutation. The overview of the present project is first described. The method improvement is presented with numerical results for a minor-actinide transmutation fast reactor.

Analysis of radionuclide migration with consideration of spatial and temporal change of migration parameters due to uplift and denudation

Shimada, Taro; Takeda, Seiji; Mukai, Masayuki; Munakata, Masahiro; Tanaka, Tadao

Materials Research Society Symposium Proceedings, Vol.1744, p.229 - 234, 2015/04

https://doi.org/10.1557/opl.2015.366

Integrated safety assessment methodology which analyzes radionuclide migration reflecting the spatial and temporal changes of disposal systems was developed for a geological disposal site with uplift and denudation, and then some case analyses for an assumed site with sedimentary rocks were carried out. The combination of uniform uplift and denudation has the most effect on the radionuclide migration because the groundwater flow velocity increases with decreasing the depth from the ground surface. In the case without denudation, tilted uplift has more effect than uniform uplift because flow velocity in tilted uplift increase with increasing hydraulic gradient. The long-term change of the geological structures including the uplift and denudation, the hydraulic conditions, and the recharge and outlet of the groundwater around a candidate site should be carefully investigated to determine the appropriate the place,depth and layout of the repository.

Elucidations of the catalytic cycle of NADH-cytochrome reductase by X-ray crystallography; New insights into regulation of efficient electron transfer

Yamada, Mitsugu*; Tamada, Taro; Takeda, Kazuki*; Matsumoto, Fumiko*; Ono, Hiraku*; Kosugi, Masayuki*; Takaba, Kiyofumi*; Shoyama, Yoshinari*; Kimura, Shigenobu*; Kuroki, Ryota; et al.

Journal of Molecular Biology, 425(22), p.4295 - 4306, 2013/11

https://doi.org/10.1016/j.jmb.2013.06.010

NADH-Cytochrome reductase (b5R), a flavoprotein consisting of NADH and flavin adenine dinucleotide (FAD) binding domains, catalyzes electron transfer from the two-electron carrier NADH to the one-electron carrier cytochrome (Cb5). The crystal structures of both the fully reduced form and the oxidized form of porcine liver b5R were determined. In the reduced b5R structure determined at 1.68 resolution, the relative configuration of the two domains was slightly shifted in comparison with that of the oxidized form. This shift resulted in an increase in the solvent-accessible surface area of FAD and created a new hydrogen-bonding interaction between the N5 atom of the isoalloxazine ring of FAD and the hydroxyl oxygen atom of Thr66, which is considered to be a key residue in the release of a proton from the N5 atom. The isoalloxazine ring of FAD in the reduced form is flat as in the oxidized form and stacked together with the nicotinamide ring of NAD. Determination of the oxidized b5R structure, including the hydrogen atoms, determined at 0.78 resolution revealed the details of a hydrogen-bonding network from the N5 atom of FAD to His49 via Thr66. Both of the reduced and oxidized b5R structures explain how backflow in this catalytic cycle is prevented and the transfer of electrons to one-electron acceptors such as Cb5 is accelerated. Furthermore, crystallographic analysis by the cryo-trapping method suggests that re-oxidation follows a two-step mechanism. These results provide structural insights into the catalytic cycle of b5R.

Mizunami Underground Research Laboratory Project; Results of the borehole investigations to understand the geological environment in and around the Main-shaft fault

Tsuruta, Tadahiko; Takeda, Masaki; Ueno, Takashi; Daimaru, Shuji; Tokuyasu, Shingo; Onoe, Hironori; Shingu, Shinya; Ishibashi, Masayuki; Takeuchi, Ryuji; Matsuoka, Toshiyuki; et al.

JAEA-Technology 2012-001, 134 Pages, 2012/03

JAEA-Technology-2012-001.pdf:41.2MB
JAEA-Technology-2012-001(errata).pdf:0.44MB
JAEA-Technology-2012-001-appendix(CD-ROM).pdf:6.37MB

Tono Geoscientific Research Unit of Japan Atomic Energy Agency (JAEA) is performing the Mizunami Underground Research Laboratory (MIU) project in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. The borehole investigations (two boreholes; 10MI22 borehole and 10MI23 borehole) have been carried out to obtain information on geological, hydrological and hydrochemical characteristics in and around the Main-shaft fault. These investigations provided that features of fracture and alteration on rock mass in and around the Main-shaft fault. Hydrological and hydrochemical properties based on the geological features were also obtained.

Hydrogeological characterization based on long term groundwater pressure monitoring

Daimaru, Shuji; Takeuchi, Ryuji; Takeda, Masaki; Ishibashi, Masayuki

Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.149 - 158, 2010/10

https://doi.org/10.1115/ICEM2010-40064

no abstracts in English

Electronic structure of GaCrN and Si-doping effects studied by photoemission and X-ray absorption spectroscopy

Song, G.*; Kobayashi, Masaki*; Hwang, J. I.*; Kataoka, Takashi*; Takizawa, Masaru*; Fujimori, Atsushi; Okochi, Takuo; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; et al.

Physical Review B, 78(3), p.033304_1 - 033304_4, 2008/07

https://doi.org/10.1103/PhysRevB.78.033304

Magnetic and superconducting properties of LaIrSi and CeIrSi with the non-centrosymmetric crystal structure

Okuda, Yusuke*; Miyauchi, Yuichiro*; Ida, Yuki*; Takeda, Yuji*; Tonohiro, Chie*; Ozuchi, Yasuhiro*; Yamada, Tsutomu*; Nguyen, D.; Matsuda, Tatsuma; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 76(4), p.044708_1 - 044708_11, 2007/04

https://doi.org/10.1143/JPSJ.76.044708

Single crystals of LaIrSi and CeIrSi were grown by the Czochralski pulling method in a tetra-arc furnace and the magnetic and superconducting properties, together with super- conductivity in CeIrCoSi, were clarified by measuring the electrical resistivity, specific heat, magnetic susceptibility, magnetization and de Haas-van Alphen (dHvA) effect. From the results of the dHvA experiment for LaIrSi, the Fermi surface is found to split into two Fermi surfaces due to the spin-orbit interaction arising from the non-centrosymmetric crystal structure. The electronic state of CeIrSi is tuned from the antiferro- magnetic state to the superconducting state by applying pressure. The upper critical field H(0) at a pressure of 2.65 GPa is found to be highly anisotropic. Large magnitude and anisotropy of H(0) in CeIrSi are consistent with the theoretical prediction for superconductivity in the non-centrosymmetric crystal structure.