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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.
Miyamoto, Seiji; Sugihara, Masayoshi*; Shinya, Kichiro*; Nakamura, Yukiharu*; Toshimitsu, Shinichi*; Lukash, V. E.*; Khayrutdinov, R. R.*; Sugie, Tatsuo; Kusama, Yoshinori; Yoshino, Ryuji*
Fusion Engineering and Design, 87(11), p.1816 - 1827, 2012/11
Times Cited Count:15 Percentile:71.81(Nuclear Science & Technology)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.
Ishidera, Takamitsu; Miyamoto, Shinya*; Sato, Haruo
Journal of Nuclear Science and Technology, 45(7), p.610 - 616, 2008/07
Times Cited Count:15 Percentile:67.86(Nuclear Science & Technology)For safety assessment of TRU waste disposal, the effective diffusion coefficients () for CO
, Cl
and I
ions in compacted bentonite (Kunigel V1) were determined as a function of NaNO
concentrations from 0.01 to 5 mol/dm
. The
values increased from 10
to 10
m
/s with increasing NaNO
concentration. The rock capacity factor
, indicative of the effective porosity, were also increased with increasing NaNO
concentration. The maximum
values of 0.21 for Cl
ion and of 0.25 for I
ion at 5 mol/dm
NaNO
concentration were lower than the net porosity of compacted bentonite (0.40). Therefore, the increases in the
values were interpreted by the decrease of anion exclusion effect. The
values for Cl
and I
ions normalized by the diffusivities for diffusants in the bulk water were found to increase in proportion to the
values on the log-log diagram. The maximum
value for CO
ion was higher than the net porosity. The high concentration of CO
ion was also found in the concentration profile in compacted bentonite. This retention of CO
ion was possibly accounted for by isotopic exchange of
C with inactive carbon of calcite in Kunigel V1.
Miyamoto, Shinya*; Sato, Mitsuyoshi*; Mihara, Morihiro
JNC TN8400 2005-028, 21 Pages, 2005/09
It is planning that radioactive wastes of high alpha concentration generated from reprocessing plant of spent nuclear fuel will be disposed in deep underground repository in Japan. Using the nitrate acid in the reprocessing process, some of radioactive wastes include lots of nitrate salts. The solubility of nitrate salts is very high and they might easily dissolve in groundwater in the repository. In the repository, many steels also will be disposed and nitrate will be reduced to ammonium ion by the interaction of steel. In this study, first the solubility experiments of nickel were performed to evaluate the effect of ammonium ion on solubility. Next the geochemical modeling also was carried out to explain results of solubility experiments using published thermodynamic data of nickel and ammonia. Under conditions of more than 1mol/dm of ammonium chloride, the enhancement of solubility of nickel was observed. It showed 2 or 3 orders magnitude of higher than those of less than 1mol/dm
of ammonium chloride. These data were explained by geochemical modeling using data of ammine complex.
Ishidera, Takamitsu; Miyamoto, Shinya*; Sato, Haruo
JAERI-Conf 2005-007, p.264 - 269, 2005/05
For safety assessment of TRU waste disposal, the effective diffusion coefficients (De) for CO, Cl
and I
ions in compacted bentonite (Kunigel V1) were determined as a function of silica sand contents under hyper alkaline condition. The obtained De values for three diffusants were on the order of 10
- 10
m
/s and increased with increasing silica sand content. The effective porosity for diffusion of Cl
and I
ions, estimated from the rock capacity factor values, were also increased with increasing silica sand content. This close relationship indicated that the increases in the De values were due to the increase in effective porosity with increasing silica sand content. In the case of CO
ion, the rock capacity factor values were higher than those for Cl
and I
ions. The Da values for CO
ion were approximately one order of magnitude lower than those for Cl
and I
ions. The differences in these behaviors suggested a possibility of isotopic exchange of
C with the carbon of calcite contained in Kunigel V1.
Ishidera, Takamitsu; Miyamoto, Shinya*; Sato, Haruo
JNC TN8400 2004-001, 21 Pages, 2004/05
For safety assessment of geological disposal of TRU waste, it is necessary to obtain the diffusivities of C-14, Cl-36 and I-129 and to estimate the effects of the dissolution of NaNOand high pH groundwater condition caused by dissolution of cementitious materials. Therefore, the effective diffusion coefficients (De) and the apparent diffusion coefficients (Da) of CO
, Cl
and I
in compacted bentonite were obtained as a function of silica sand content and NaNO
concentration under high pH condition by Through-diffusion method. Furthermore, the diffusion mechanisms of CO
, Cl
and I
were discussed.The obtained De values of CO
, Cl
and I
were in a range of 10
to 10
m
/s order and Da values in a range of 10
to 10
m
/s order (CO
) and 10
m
/s order (Cl
and I
The De and Da values of CO
, Cl
and I
increased with increasing silica sand content. The changes of De and Da values appeared to be estimated by smectite partial density. The De values of CO
, Cl
and I
increased with increasing NaNO
concentration. The increases were interpreted by the decrease of anion exclusion effect. Furthermore, it seems that the pathways of Cl
and I
were limited to the interstitial pore space. The CO
ions were probably retained in the Kunigel V1 as the precipitation of calcite.
Ishidera, Takamitsu; Miyamoto, Shinya; Sato, Haruo
Saikuru Kiko Giho, (25), p.85 - 93, 2004/00
The concept of air transport of A Type package containing nuclear fuel materials according to the nuclear disaster countermeasures law, and the experience of a transportation of plutonium solution from France are shown.
Ishidera, Takamitsu; Sato, Haruo; Miyamoto, Shinya
Migration 2003, PB-4, 145 Pages, 2003/00
None
Sato, Haruo; Miyamoto, Shinya
Proceedings of 3rd NUCEF International Symposium (NUCEF 2001), 675 Pages, 2002/00
None
Sato, Haruo; Miyamoto, Shinya
Workshop on Modelling of Coupled Transport Reaction Processes(TrePro2002), 0 Pages, 2002/00
None
Sato, Haruo; Miyamoto, Shinya
JNC TN8400 2001-018, 27 Pages, 2001/03
We have studied performance as a diffusion barrier of bentonite which is one of the candidate buffer materials for geological disposal of high-level radioactive waste. Various functions are expected for bentonite and a retardation function in diffusion process of radionuclides released from vitrified waste is also one of them. In this study, diffusion and migration of Pb i bentonite, particularly for the effects of bentonite dry density, silica sand content and temperature on apparent diffusion coefficients (Da) were experimentally studied from the viewpoints of (1) database development and expansion for important nuclides in dose evaluation, (2)confirmation of the validity or conservativity of distribution coefficient (Kd) used in the second progress report, and (3)understanding the mechanism of diffusion and migration behaviour in bentonite. In diffusion experiments, a Na-bentonite, Kunigel-VI (R) (Na-smectite, 46-49wt%) was used and the experiments were carried out at dry densities of 0.8, 1.4, 1.6 and 1.8Mg/m and temperatures of 22.5
2.5 and 60
0.1
C by in-diffusion method. The experiments i the systems with silica sand of 30 and 50wt% were also carried out only at a bentonite dry density of 1.6Mg/m
. Since Pb is much contained in the bentonite,
Pb which is radioactive, was used as a tracer in all experiments and analysed by a liquid scintillation counter. All experiments were performed in a N
atmospheric glove-box (O
concentration
1ppm). Additionally, the background of
Pb in the bentonite was measured to obtain reliable data. The measurements were carried out as a function of bentonite dry density (0.8, 1.6, 1.8Mg/m
), saturation period (40-71d) and bentonite slice thickness (0.2-2mm). Furthermore, a HNO
solution used for removal of
Pb from bentonite slices, liquid scintillator and an empty polyethylene vial were also analyzed. Consequently, no significant difference in ...
Sato, Haruo; Miyamoto, Shinya
Migration '01 (Dai-8-Kai Chichu Niokeru Akuchinido Oyobi Kaku Bunretsu Seiseibutsu No Kagaku Oyobi Iko Kyodo Ni Kansuru Kuni, 0 Pages, 2001/00
None
Sato, Haruo; Miyamoto, Shinya
PW-10, 0 Pages, 2001/00
None
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.
Kofuji, Hirohide; Yano, Tetsuji*; Myochin, Munetaka; Okita, Takeshi*; Miyamoto, Shinya*
no journal, ,
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 in this study.
Yano, Tetsuji*; Tateno, Hayato*; Kishi, Tetsuo*; Okita, Takeshi*; Matsuyama, Kanae*; Miyamoto, Shinya*; Kofuji, Hirohide; Myochin, Munetaka
no journal, ,
Miyamoto, Seiji; Sugihara, Masayoshi*; Shinya, Kichiro*; Nakamura, Yukiharu*; Toshimitsu, Shinichi; Sugie, Tatsuo; Kusama, Yoshinori; Yoshino, Ryuji
no journal, ,
When Plasma Control System (PCS) generates wrong signal to the PF coils and in-vessel vertical stabilization (VS) coils, it could be happen that the vertical force somewhat larger than presently specified could be generated. Example is that though plasma moves downward, but PCS erroneously recognizes it is moving upward. Then PF coils start to generate the field pattern that tends to push plasma further downward and resultantly the force could be larger than the present specification, in which it is evaluated with the assumption that control system (PF coils) does nothing (i.e., short-circuited.) In fact, in the existing machines, this is the worst case. The DINA code is used to analyze the vertical force, which has been updated to incorporate the recent design change of the vacuum vessel and in-vessel VS coils. In the presentation, analysis of VS effect on the vertical force is discussed using the updated DINA code.
Amamoto, Ippei; Fukushima, Mineo; Matsuyama, Kanae*; Okita, Takeshi*; Miyamoto, Shinya*; Utsunomiya, Kazuhiro*; Yano, Tetsuji*
no journal, ,
no abstracts in English
Kofuji, Hirohide; Yano, Tetsuji*; Myochin, Munetaka; Matsuyama, Kanae*; Okita, Takeshi*; Miyamoto, Shinya*
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