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Okamoto, Yoshihiro; Kobayashi, Hidekazu; Shiwaku, Hideaki; Sasage, Kenichi; Hatakeyama, Kiyoshi*; Nagai, Takayuki
Journal of Non-Crystalline Solids, 551, p.120393_1 - 120393_8, 2021/01
Times Cited Count：6 Percentile：32.24(Materials Science, Ceramics)The chemical state of ruthenium in simulated iron phosphate radioactive waste glass was investigated by conventional X-ray absorption fine structure (XAFS) and imaging XAFS analyses. The EXAFS analysis suggested that ruthenium was contained as glass phase when content of the waste components was less than 10wt.% in 30 mol%Fe
O
-PO
base glass. In other samples, crystalline RuO was predominant. According to the imaging XAFS analysis, RuO particles in all samples had length smaller than 50
m. Aggregations of RuO, which are found in nuclear waste borosilicate glass, were not seen in any of the iron phosphate glass samples.
Nagai, Takayuki; Sasage, Kenichi; Okamoto, Yoshihiro; Shiwaku, Hideaki; Yamagishi, Hirona*; Ota, Toshiaki*; Inose, Takehiko*; Sato, Seiichi*; Hatakeyama, Kiyoshi*; Takahashi, Tomoe*; et al.
JAEA-Research 2019-003, 94 Pages, 2019/09
JAEA-Research-2019-003.pdf:7.92MB
The local structures of glass-forming elements and waste elements would change by the chemical composition of waste glass including those elements. In this study, simulated waste glass samples were prepared from borosilicate glass frit including phosphorus (P) or vanadium (V), and we investigated local structures of boron, sodium, and waste elements in these P glass and V glass samples by using synchrotron XAFS measurements in soft and hard X ray region.
Nagai, Takayuki; Kobayashi, Hidekazu; Shimamura, Keisuke; Oyama, Koichi; Sasage, Kenichi; Okamoto, Yoshihiro; Shiwaku, Hideaki; Yamanaka, Keisuke*; Ota, Toshiaki*
JAEA-Research 2018-005, 72 Pages, 2018/09
JAEA-Research-2018-005.pdf:28.2MB
Addition of radioactive waste to a borosilicate glass frit affects the local structures of glass-forming elements and waste elements in a waste glass produced in a vitrification process. In this study, simulated waste glass samples were prepared from borosilicate glass frit including phosphorus pentaoxide, and we investigated local structures of sodium (Na), boron (B), and waste elements in these glass samples by using synchrotron XAFS measurements in soft and hard X ray region.
Nagai, Takayuki; Kobayashi, Hidekazu; Sasage, Kenichi; Ayame, Yasuo; Okamoto, Yoshihiro; Shiwaku, Hideaki; Yamanaka, Keisuke*; Ota, Toshiaki*
JAEA-Research 2017-005, 54 Pages, 2017/06
JAEA-Research-2017-005.pdf:16.17MB
Addition of radioactive waste to a borosilicate frit affects the local structures of boron (B) and waste elements in a waste glass. Synchrotron XAFS measurement was applied to investigate the local structural changes by using simulated waste borosilicate glass samples. Following results were obtained by the B K-edge XAFS analysis. It was confirmed that B K-edge XAFS analysis enables us to discriminate sp
type boron (BO) from sp
type boron (BO
). Addition of waste elements to a glass frit increases the percentage of BO and decreases that of BO. By decreasing the SiO/AlO ratio or increasing the (SiO+BO)/AlO ratio in the glass composition, the BO percentage increases and the BO percentage decreases. Addition of PO decreases the BO percentage and increases the BO percentage. Following results were obtained from XAFS measurement of the waste elements. Cerium (Ce) valence is more reduced with the increase of the BO content. Addition of PO has a tendency to reduce the Ce valence and to enhance deposition of Zr oxide. Deposition of ruthenium compounds separated from glass phase can not be improved by changing the BO content. This study was performed as a part of the project, "Improvement of vitrification process of high-level radioactive liquid wastes" on the foundation business of the Agency for Natural Resources and Energy.
Nagai, Takayuki; Akiyama, Daisuke*; Sato, Nobuaki*; Sasage, Kenichi
Busshitsu, Debaisu Ryoiki Kyodo Kenkyu Kyoten Kenkyu Seika Hokokusho (Heisei-28-Nendo) (CD-ROM), 1 Pages, 2017/03
no abstracts in English
Nagai, Takayuki; Kobayashi, Hidekazu; Sasage, Kenichi; Ayame, Yasuo; Okamoto, Yoshihiro; Shiwaku, Hideaki; Matsuura, Haruaki*; Uchiyama, Takafumi*; Okada, Yukiko*; Nezu, Atsushi*; et al.
JAEA-Research 2016-015, 52 Pages, 2016/11
JAEA-Research-2016-015.pdf:37.48MB
The local structure of waste elements in simulated waste glasses including V was estimated by using synchrotron XAFS measurement in this study. The results are as follows. (1) V has a high possibility which exists in the glass phase in the case of frit, and V can regard both samples as stable 4 coordination structure. (2) Zn, Ce, Nd, Zr, and Mo exist in the glass phase, and the difference is admitted by the percentage of Ce(III) and Ce(IV) by the composition. (3) Ru is separated from the glass phase as RuO crystalline, both of metal and oxide exist in Rh, and Pd is separated out as metal. (4) It was confirmed that the regularity of the local structure of Zr and Mo in the molten glasses retreats as a result of the XAFS measurement at high temperature. (5) The XAFS measurement of molten glasses were performed at 1200
C, so it would be possible to acquire excellent data by improving the shapes of the sample cell.
Nagai, Takayuki; Sato, Nobuaki*; Sasage, Kenichi
Busshitsu, Debaisu Ryoiki Kyodo Kenkyu Kyoten Kenkyu Seika Hokokusho (Heisei-27-Nendo) (CD-ROM), 2 Pages, 2016/03
no abstracts in English
; ; ; Sasage, Kenichi
JNC TY8400 2003-004, 41 Pages, 2003/03
JNC-TY8400-2003-004.PDF:0.83MB
no abstracts in English
Ouchi, Jin; ; Kawamura, Kazuhiro; ; ; Sasage, Kenichi; Odakura, Makoto
PNC TN8410 97-044, 53 Pages, 1997/03
The glass transition temperature of simulated waste glass was measured by DTA installed in CPF (Chemical Processing Facility) and HTS (High Level Waste Technology Section). This measurement was intended to confirm the agreement between hot and cold data as a part of characterization of high level waste glass. Glass transition temperature is an index of the temperature to keep thermal stability of high-level waste glass. Since devitrification deteriorates characteristics of waste glass above glass transition temperature, it is necessary to measure glass transition temperature and keep glass temperature below glass transition temperature. The conventional method to determine glass transition temperature is the measurement of thermal expansion, but DTA is adopted for radioactive sample because of easier preparation. We obtained following results by measuring glass transition temperature of simulated waste glasses after calibration with standard specimen : (1)The average glass transition temperature of TVF waste glass (P0798) measured by DTA in HTS and CPF was 494C (standard deviation 3 
: 8.2C) and 495C (3: 1.8C), respectively. The difference between two analyzer was 1C. It shows the good agreement between hot and cold DTA data. (2)Glass transition temperature of P0798 measured by thermal expansion method was 495C(3: 8.1C) and it agrees well with that measured by DTA. (3)The average glass transition temperature of simulated highly waste-loading glass (P1102) measured by DTA in HTS and CPF was 510.5 
2.5C.
Yoneya, Masayuki; Kawamura, Kazuhiro; ; Sasage, Kenichi; ; Ouchi, Jin
Donen Giho, (98), p.85 - 90, 1996/06
None
; ; ; Kawamura, Kazuhiro; Sasage, Kenichi; ; Ouchi, Jin
PNC TN8100 94-002, 104 Pages, 1994/02
no abstracts in English
Nagai, Takayuki; Sasage, Kenichi; Oyama, Koichi; Sato, Nobuaki*; Inose, Takehiko*; Sato, Seiichi*; Hatakeyama, Kiyoshi*
no journal, ,
no abstracts in English
Kobayashi, Hidekazu; Nagai, Takayuki; Okamoto, Yoshihiro; Sasage, Kenichi; Amamoto, Ippei; Takebe, Hiromichi*; Nakamura, Hiroki*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
no abstracts in English
Miyauchi, Atsushi; Yamanaka, Atsushi; Morikawa, Yo; Sasage, Kenichi; Yamashita, Teruo
no journal, ,
no abstracts in English
Sasage, Kenichi; Kobayashi, Hidekazu; Ayame, Yasuo; Fujiwara, Koji; Shiotsuki, Masao; Miura, Nobuyuki
no journal, ,
Kofuji, Hirohide; Watanabe, So; Goto, Ichiro; Oriuchi, Akio; Takeuchi, Masayuki; Kobayashi, Hidekazu; Sasage, Kenichi
no journal, ,
Vitrification procedure for the extraction chromatography using porous silica covered with extractant were examined. In this method, it was expected that minor actinide (MA) were separated from high level radioactive liquid waste using extractant CMPO and/or HDEHP. In this study, vitrified adsorbent with simulated high level liquid waste were prepared and evaluated from some viewpoints of high level waste form properties. As the results, selected adsorbent were generally well vitrified and had enough chemical durability.
Nakazaki, Katsutoshi; Morikawa, Yo; Yamashita, Teruo; Sasage, Kenichi; Nakajima, Masayoshi
no journal, ,
no abstracts in English
Nishihara, Kenji; Oigawa, Hiroyuki; Nakayama, Shinichi; Fujiwara, Takeshi; Kobayashi, Hidekazu; Kano, Shigeru; Sasage, Kenichi; Yamashita, Teruo; Ono, Kiyoshi; Shiotani, Hiroki
no journal, ,
The reduction of the storage facility and repository were evaluated for the cases with or without partitioning of Sr-Cs and transmutation of MA in the advanced FBR fuel cycle with the cost estimation for the storage facilities, transporting and repository. As the result, the transmutation of minor actinides is inevitable for the small repository because the heat generation by 
Am is considerable in FBR. The introduction of partitioning, transmutation and long-term storage enable the very compact layout in the repository like TRU wastes such as hulls and end-pieces of the fuel assembly. The cost for the storage and disposal in this case is much smaller than that in other cases, which mitigates the cost increase by the separation process and transmutor.
