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Tomita, Kana*; Kishi, Tetsuo*; Matsumura, Daiju; Yano, Tetsuji*
Journal of Non-Crystalline Solids, 597, p.121891_1 - 121891_10, 2022/12
Times Cited Count:2 Percentile:16.45(Materials Science, Ceramics)Kado, Rikiya*; Kishi, Tetsuo*; Lelong, G.*; Galoisy, L.*; Matsumura, Daiju; Calas, G.*; Yano, Tetsuji*
Journal of Non-Crystalline Solids, 539, p.120070_1 - 120070_8, 2020/07
Times Cited Count:6 Percentile:28.07(Materials Science, Ceramics)Kofuji, Hirohide; Yano, Tetsuji*; Myochin, Munetaka; Matsuyama, Kanae*; Okita, Takeshi*; Miyamoto, Shinya*
Proceedings of 22nd International Conference on Nuclear Engineering (ICONE-22) (DVD-ROM), 6 Pages, 2014/07
For the research and development of the nuclear waste disposal concept suitable to the pyrochemical processing system and its performance evaluation, the iron-phosphate glass is examined as an alternative waste form for high level waste generated from electro-refining process. In order to enhance the waste element content in the glass matrix and improve the durability of the waste form, optimization experiments of the glass composition were carried out and the effect of additional other transition metal oxides was found out in this study.
Kofuji, Hirohide; Yano, Tetsuji*; Myochin, Munetaka; Matsuyama, Kanae*; Okita, Takeshi*; Miyamoto, Shinya*
Procedia Chemistry, 7, p.764 - 771, 2012/00
Times Cited Count:14 Percentile:95.27(Chemistry, Analytical)As a part of the research and development for the nuclear waste disposal concept suitable to the advanced fuel cycle systems and its performance evaluation, the iron-phosphate glass is examined as an alternative waste form for high level waste generated from pyrochemical reprocessing. In order to enhance the waste element content in the glass matrix and improve the durability of the waste form, optimization experiments of glass composition were carried out and the effect of additional other transition metal oxides was found out in this study.
Amamoto, Ippei; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Takasaki, Yasushi*; Shibayama, Atsushi*; Yano, Tetsuji*; Nakada, Masami; Okamoto, Yoshihiro
Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.503 - 508, 2010/10
The main objective of this development is to recycle the purified eutectic medium of the pyroreprocessing, delaying its disposal for as long as possible. We have introduced the simple filtration method to remove the rare earth element (REE) particles which were formed due to the conversion of REE chlorides to phosphates. Here, the iron phosphate glass is used as a filtration medium for the removal of FP particles. However, some soluble FP such as compounds of alkali-metals, alkaline-earth metals, etc. still remain in the eutectic medium. This time around, on an experimental basis, the iron phosphate glass has been used as a sorbent instead, to remove the soluble FP. We have obtained some positive results and have intention to incorporate it into the spent electrolyte recycle process as a part of the FP separation and immobilization system.
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*
Nuclear Technology, 171(3), p.316 - 324, 2010/09
Times Cited Count:11 Percentile:58.00(Nuclear Science & Technology)The separation technique by phosphate conversion of FP from NaCl-KCl or NaCl-2CsCl as the medium of the spent electrolyte of pyroprocessing is being developed at RIAR in Russia. To ascertain the technical feasibility of applying this RIAR's method for recycling of spent electrolyte which composed of FP such as AL, ALE, and REE and 3LiCl-2KCl as the medium, preliminary study was undertaken at JAEA. This study occupies an auxiliary role which is forwarded as a part of FaCT Project of Japan. As a first approach, the thermodynamic analysis to understand the behaviours of FP in the electrolyte was carried out after literature research and acquisition of required thermodynamic properties. Preliminary experiment was then undertaken to observe the conversion behaviours of chlorides to phosphate. In this paper, these results are shown and are evaluated to discern the feasibility of the phosphate conversion method.
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Tsuzuki, Tatsuya*; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*
Proceedings of 12th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM '09/DECOM '09) (CD-ROM), 9 Pages, 2009/10
This study is carried out to make the pyroprocessing hold a competitive advantage. As one of the measures is to reduce the volume of HLW, the phosphate conversion method is applied for removal of FP from the spent electrolyte in this paper. Though the removing target elements in the electrolyte are alkali metals, alkaline earth metals and lanthanoid elements, only lanthanoid elements and lithium form the insoluble phosphates by reaction with LiPO
. Therefore, as the first step, the precipitation experiment was carried out to observe the behaviours of elements which form the insoluble precipitates. Then the filtration was experimented to remove precipitates in the spent electrolyte using Fe
O
-P
O
glass system as a filtlation medium which is compatible material with the glassification. The result of separation of precipitates by filtration was effective and attained almost 100
.
Amamoto, Ippei; Myochin, Munetaka; Yano, Tetsuji*; Akagi, Naoto*; Segawa, Hiroyo*; Shibata, Shuichi*
no journal, ,
Phosphate glasses have received much attention for the development of new low-melting glasses with low environmental load. However, their low chemical durability prevents their application for practical use. Recently, the addition of FeO
was found to improve their chemical durability. Due to their high durability and high capacity of solution of dopants, iron phosphate glass system has been suggested to be utilized as new materials. In this work, the effect of the addition of other transition metal oxides on the properties of iron phosphate glass was investigated. In addition, the pseudo fission products as nuclear waste was added and their glass formation and chemical durability were investigated. All the glass batches formed homogenous melts at 1250 in the centigrade scale and vitrified without crystallization by pouring on the carbon plate. It was found that the substitution of a part of Fe
O
by MnO
or CoO did not cause large changes in the thermal properties.
Amamoto, Ippei; Myochin, Munetaka; Akai, Naoto*; Yano, Tetsuji*; Shibata, Shuichi*
no journal, ,
The chemical durability of iron phosphate glasses was investigated by substituting MnO or CoO for a part of Fe
O
and by addition of pseudo nuclear waste (NW). The glass structure was also analyzed by X-ray photoelectron spectroscopy (XPS). The substitution of MnO
and CoO decreased chemical durability of the glass without NW, while NW remarkably increased the chemical durability of glasses substituted by MnO
and CoO. According to XPS measurement, the substitution of MnO
and CoO increased bridging oxygen ratio and NW decreased it. The fraction of bridging oxygen is suggested to be one of the factors to affect the improvement of chemical durability.
Amamoto, Ippei; Kofuji, Hirohide; Tsuzuki, Tatsuya*; Mitamura, Naoki*; Takasaki, Yasushi*; Shibayama, Atsushi*; Yano, Tetsuji*; Terai, Takayuki*
no journal, ,
no abstracts in English
Amamoto, Ippei; Fukushima, Mineo; Matsuyama, Kanae*; Okita, Takeshi*; Miyamoto, Shinya*; Utsunomiya, Kazuhiro*; Yano, Tetsuji*
no journal, ,
no abstracts in English
Yano, Tetsuji*; Akagi, Naoto*; Shibata, Shuichi*; Amamoto, Ippei
no journal, ,
In order to clarify the origins of the high chemical durability of iron phosphate glasses and find more stable glass composition, the transition metal oxides were added by the replacement of a part of the iron oxide, prepared the glasses by melt-quenching method and their thermal properties and chemical durabilities were measured. The structures of the glasses and their surfaces were analyzed using X-ray photoelectron spectroscopy. The bulk samples were fractured in vacuum to obtain pristine surfaces, and the photoelectrons emitted from the analyzed surface by the monochromatic X-ray irradiation were collected. From the result, the dissolution rates of the sample glasses were correlated with the structural factors obtained from the XPS data, and strong correlations with the chemical shifts of the core electron spectra of oxygen and phosphorus ions were found, which are on the different trends found in general phosphate glass system like alkali phosphate glass.
Amamoto, Ippei; Fukushima, Mineo; Matsuyama, Kanae*; Okita, Takeshi*; Miyamoto, Shinya*; Utsunomiya, Kazuhiro*; Yano, Tetsuji*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Motohashi, Takumi*; Takasaki, Yasushi*; Shibayama, Atsushi*; Yano, Tetsuji*
no journal, ,
no abstracts in English
Kofuji, Hirohide; Amamoto, Ippei; Matsuyama, Kanae*; Okita, Takeshi*; Myochin, Munetaka; Yano, Tetsuji*
no journal, ,
The iron phosphate glass has been investigated for the high level waste originated from the pyrochemical reprocessing. The results of the optimization of glass composition were introduced in this report for high FP loading and improvement of chemical durability of the waste form.
Yano, Tetsuji*; Akagi, Naoto*; Shibata, Shuichi*; Okita, Takeshi*; Matsuyama, Kanae*; Miyamoto, Shinya*; Amamoto, Ippei; Kofuji, Hirohide
no journal, ,
Surface structures of iron phosphate glasses (IPG) are investigated in order to know the origin of the high chemical durability using X-ray photoelectron spectroscopy. In this study, several IPG samples in which a part of iron oxide are replaced by other transition metal oxides are prepared and subjected to the chemical durability test. Surface structures are investigated before and after the durability test and the information on the structural changes are obtained.
Tajimi, Yuri*; Watanabe, So; Kofuji, Hirohide; Yano, Tetsuji*; Kado, Rikiya*; Matsuura, Haruaki*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Tsuzuki, Tatsuya*; Mitamura, Naoki*; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*
no journal, ,
no abstracts in English
Yano, Tetsuji*; Kishi, Tetsuo*; Nakata, Yoshiyuki*; Kofuji, Hirohide; Takeuchi, Masayuki
no journal, ,