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Ouchi, Kazuki
Hosha Kagaku, (49), p.3 - 7, 2024/03
I introduce the elucidation of the deposition following the oxidation state of uranium and the electrochemical behavior of uranium(IV) chloride in an ionic liquid-organic mixture, as a basic study of in-solution reactions. In addition, I introduce the development of separation methods for actinides using a microchemical chip and polyacrylamide gel electrophoresis, as an applied study for quantitative analytical methods for small amounts of samples.
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Suzuki, Masahiro; Tachihara, Joji; Takato, Kiyoto; Okita, Takatoshi; Satone, Hiroshi*; Suzuki, Michitaka*
Mechanical Engineering Journal (Internet), 8(3), p.21-00022_1 - 21-00022_9, 2021/06
To reduce the hold-up of the nuclear fuel materials in the glove box and the external exposure dose, the technology of the MOX powder adhesion prevention by the nanoparticle coating to the acrylic panels of the glove box has been developed. The surface analysis by means of atomic force microscopy (AFM) showed that the acrylic test piece surface coated with nanoparticles had a higher root mean square roughness value than that non-coated with nanoparticles. Due to the formation of nano-sized tiny rugged surface, the nanoparticle coating reduced the minimum adhesion force between the UO particles and the acrylic test piece surface with the smallest particle size of about 5 m where desorption was observed, by about one-tenth. Moreover, the nanoparticle coating reduced the amount of the MOX powder adhering to the acrylic test piece to about one-tenth. In this study, it was found that applying the nanoparticle coating to the acrylic panels of glove box can prevent the adhesion of nuclear fuel materials. This method is effective for reducing the hold-up of the nuclear fuel materials in the glove box, the external exposure dose and improving the visibility of the acrylic panels.
Kawasaki, Kohei; Shinada, Kenta; Okamoto, Naritoshi; Kageyama, Tomio; Eda, Takashi; Okazaki, Hiro; Suzuki, Hiromichi; Yamamoto, Kazuya; Otabe, Jun
JAEA-Technology 2020-025, 80 Pages, 2021/03
Plutonium Fuel Production Facility was built in 1988 for the purpose of mainly producing MOX fuel of the prototype fast breeder reactor MONJU, and large glove boxes were installed for handling unsealed nuclear fuel material remotely. The panels of these glove boxes are made of acrylic, except for those installed after December 2013. For fires inside the glove box, automatic fire extinguishing systems using halides have been introduced since the beginning of construction, but for fires outside the glove box, there have been issues with direct measures for acrylic. Therefore, we have developed a fireproof sheet that mitigates the effect of fire outside the glove box on the panels as much as possible. As a result, fire-retardant sheets have been selected and attached to the glove box panels. We conducted a flammability test of the acrylic plate attached with these fireproof sheets and a usage environment influence test of fireproof sheets, and obtained good results. In addition, we set up a working group in the Plutonium Fuel Development Center in view of reducing external exposure during the work of attaching fireproof sheets, in which we discussed and examined the work procedure, and summarized it in the basic procedure manual.
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Suzuki, Masahiro; Tachihara, Joji; Takato, Kiyoto; Okita, Takatoshi; Satone, Hiroshi*; Suzuki, Michitaka*
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 6 Pages, 2020/08
To reduce the hold-up of the nuclear fuel materials in the glove box and the external exposure dose, the technology of the MOX powder adhesion prevention by the nanoparticle coating to the acrylic panels of the glove box has been developed. Due to the formation of nano-sized tiny rugged surface, the nanoparticle coating reduced the minimum adhesion force between the UO particles and the acrylic test piece surface with the smallest particle size of about 5 m where desorption was observed, by about one-tenth. Moreover, the nanoparticle coating reduced the amount of the MOX powder adhering to the acrylic test piece to about one-tenth. In this study, it was found that applying the nanoparticle coating to the acrylic panels of glove box can prevent the adhesion of nuclear fuel materials. This method is effective for reducing the hold-up of the nuclear fuel materials in the glove box, the external exposure dose and improving the visibility of the acrylic panels.
Saga, Kaname*; Suzuki, Hideya; Matsumura, Tatsuro; Tsukahara, Takehiko*
Analytical Sciences, 35(4), p.461 - 464, 2019/04
Times Cited Count:3 Percentile:12.17(Chemistry, Analytical)The phase transition-based gelification phenomenon of poly--isopropylacrylamide (PNIPAAm) in aqueous solutions has a great potential in developing new waste-free extraction processes of metal ions. By using hydrophobic diglycolamide-typed ligands in gelification extraction, a one-step complete extraction of all the RE ions from a nitric acid solution was successfully realized.
Chen, J.; Maekawa, Yasunari; Yoshida, Masaru; Tsubokawa, Norio*
Journal of Polymer Science, Part B; Polymer Physics, 40, p.134 - 141, 2001/11
Times Cited Count:7 Percentile:27.46(Polymer Science)no abstracts in English
Chen, J.; Yoshida, Masaru; Maekawa, Yasunari; Tsubokawa, Norio*
Polymer, 42(23), p.9361 - 9365, 2001/11
Times Cited Count:31 Percentile:72.19(Polymer Science)no abstracts in English
Takahashi, Yoshio*; Kimura, Takaumi
Bulletin of the Chemical Society of Japan, 74(10), p.1899 - 1900, 2001/10
Times Cited Count:0 Percentile:0(Chemistry, Multidisciplinary)no abstracts in English
*; Tetsu, Keiichi*;
JNC TN8430 2001-003, 58 Pages, 2001/03
Handling methods and test conditions of hydraulic tests for NETBLOCK system had been examined by using acrylic and/or artificial rock specimen. A natural rock specimen (granite : excavated from Kamaishi mine) with fracture intersection was formed into practicable size for NETBLOCK system. Recently, we conducted a series of hydraulic test, in order to study the influence of fracture intersection by using the natural rock specimen. Hydraulic tests were conducted under several centimeters of head, which could be controlled by improved system because hydraulic permeability of target fractures were high. As a result, 1010(m/s) orders of hydraulic transmissivity of target fractures could be measured. A low permeability in the NW direction at the lower fracture was estimated from the heterogeneous head distribution. However, it is also expected that turbulence flow might be occurred under this study condition because fracture permeability is high and flow rate through the fracture is relatively high. In case of turbulence-flow, an estimated hydraulic transmissivity is low. High-viscosity fluid hydraulic test to achieve laminar flow will be needed for correcting an evaluated transmissivity.
Takeshita, Kenji*; Nakano, Yoshio*; Matsumura, Tatsuro
Genshiryoku Bakkuendo Kenkyu, 7(1), p.11 - 16, 2001/03
no abstracts in English
Hendri, J.*; Hiroki, Akihiro*; Maekawa, Yasunari; Yoshida, Masaru; Katakai, Ryoichi*
Radiation Physics and Chemistry, 60(6), p.617 - 624, 2001/03
Times Cited Count:33 Percentile:89.46(Chemistry, Physical)no abstracts in English
Motoishi, Shoji; Kobayashi, Katsutoshi; Saeki, Hideya*
JAERI-Tech 2000-070, 34 Pages, 2000/12
no abstracts in English
Tochiyama, Osamu*
JNC TJ8400 2000-044, 53 Pages, 2000/02
To estimate the polyelectrolyte effect and the effect of the heterogeneous composition of humic acids, the complex formation constants of Eu(III) and Ca(II) with Aldrich humic acid and polyacrylic acid were obtained, for Eu(10 to 10 M) by solvent extraction with TTA and TBP in xylene, for Ca (10M) with TTA and TOPO in cyclohexane and for Ca(10M) by using ion-selective electrode. By defining the apparent formation as = [MR]/([M][R]), where [R] denotes the concentration of dissociated functional group, [M] and [MR] denote the concentration of free and bound metal ion and pcH is defined as-log[H], the values of log have been obtained at pcH 4.8 - 5.5 in 0.1 - 1.0M NaClO and NaCl. Log of Eu-humate varied from 5.0 to 9.3 and that of Ca-humate from 2.0 to 3.4..For both humate and polyacrylate, log increased with pcH or with the degree of dissociation. The increase in the ionic strength O.1 to 1.0 M decreased the log, the decrease in log of Eu(III)-humate is 1.6, that of Eu(III), polyacrylate 0.7, that of Ca(II)-humate 1.9 and that of Ca(II)-polyacrylate 1.2. While the increase in the metal ion produced no effect on log of polyacrylate, log of humate decreased. Depending on the concentration of Eu(III), the coexistence of Ca(II) reduced log of humate by 0 to 0.8. The dependence of log of humate on the metal ion concentration suggests the coexistence of strong and weak binding sites in the hmnic acid.
Yoshida, Masaru; Hendri, J.*; Maekawa, Yasunari; Kume, Tamikazu; Katakai, Ryoichi*; Said, A. E. A.; Hegazy, E. A.
Chitin and Chitosan; Chitin and Chitosan in Life Science, p.43 - 46, 2000/00
no abstracts in English
Takahashi, Yoshio*; Kimura, Takaumi; Kato, Yoshiharu; Minai, Yoshitaka*
Environmental Science & Technology, 33(22), p.4016 - 4021, 1999/00
Times Cited Count:46 Percentile:74.36(Engineering, Environmental)no abstracts in English
Takahashi, Yoshio*; Kimura, Takaumi; Kato, Yoshiharu; *; *; *
Journal of Radioanalytical and Nuclear Chemistry, 239(2), p.335 - 340, 1999/00
Times Cited Count:15 Percentile:72.22(Chemistry, Analytical)no abstracts in English
Hiroki, Akihiro*; Yoshida, Masaru; *; Asano, Masaharu; N.Reber*; R.Spohr*; Kubota, Hitoshi*; Katakai, Ryoichi*
Radiat. Eff. Defects Solids, 147, p.165 - 175, 1999/00
no abstracts in English
Watanabe, Ryuzo*
PNC TJ9601 98-005, 85 Pages, 1998/03
To fabricate a long life fuel cladding tubes for the fast breeder reactor, the concept of functionally graded material was applied for the material combination of molybdenum/stainless steel/ titanium, in which titanium is placed at the inner side to withstand against fission products and neutron irradiation, and molybdenum at the outer side to withstand corrosion by liquid sodium coolant. Slurry dipping method was employed for the processing because of its capability of shape forming and microstructural control. The graded layers of titanium and molybdenum were formed on both sides of stainless steel substrate according to an optimum composition profile for the thermal stress reduction. Such graded layers were successfully formed by slurry dipping. Dispersion, sedimentation, viscosity, rheology, as well as yield value, of the slurries were investigated in detail inconnection with properties of dispersion medium, dispersion reagent, binder and raw powders. Low- and high-viscosity slurries were investigated to enlarge a possibility of film thickness control. For the low-viscosity slurry it is necessary to suppress the sedimentation of dispersion particles, while for the high-viscosity slurry it turned out to be important to clarify the flow characteristics of the slurry for the determination of the yield value, which is needed for the precise control of the dip-coated layer thickness. The forming conditions were determined for the low-viscosity slurry in taking sedimentation rate and sedimentation height as measures of slurry stability and dispersion, respectively. It was confirmed that slow sedimentation and low sedimentation height gave reproducible film forming. The high-viscosity slurry was free from sedimentation, and the control of the film thickness with viscosity and yield value was rather easier. The consolidation Process of the dip-coated layer, including drying and debinding, followed conventional powder metallurgical techniques, with particular ...