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Segawa, Tomoomi; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Kawaguchi, Koichi; Ishii, Katsunori; Sato, Hisato; Fukasawa, Tomonori*; Fukui, Kunihiro*
Proceedings of International Nuclear Fuel Cycle Conference / Light Water Reactor Fuel Performance Conference (Global/Top Fuel 2019) (USB Flash Drive), p.738 - 745, 2019/09
In the MOX fuel fabrication process, the dry grinding technology of mixed oxide pellets have been developed for the effective use of nuclear fuel materials. To develop a technology to control the particle size of dry recovered powder, the performance of the buhrstone mill and the collision plate type jet mill were studied using a simulated powder of particle size distribution about 500 
m. We found that the particle size can be controlled at the range of about 250 m or less by both by adjusting the clearance between the grinding wheels of the buhrstone mill, and the clearance and elevation angle of the clarification zone of the collision plate type jet mill. And furthermore, the collision plate type jet mill is considered to be suitable for particle size control because the operating parameters of the classifier can be finely adjusted.
Kawaguchi, Koichi; Segawa, Tomoomi; Yamada, Yoshikazu; Suzuki, Masahiro
no journal, ,
For the purpose of pulverizer selection for a dry recycled MOX powder with the size distribution suitable for a sintered density adjustment of MOX pellet, characterisity and performance of several types of pulverizer were evaluated. In this session, results of pulverizing characterisity of two jet mills with different working pressure are reported.
Segawa, Tomoomi; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Sato, Hisato
no journal, ,
The optimizing the centrifugal classifier which influences the classification performance of collision plate-type jet mill was examined for the purpose of the particle size adjustment of recycle powder the MOX pellets. In order to adjust the particle size of recycle powder to 10-250 m, the pulverization test of the simulated raw powder was carried out using the newly prepared components as a parameter. The prospect that the particle size can be adjusted within the range of 10-250 m for recycle powder was obtained by optimizing the parameter of the centrifugal classifier of collision plate-type jet mill.
Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Sato, Hisato
no journal, ,
no abstracts in English
Kawaguchi, Koichi; Segawa, Tomoomi; Yamada, Yoshikazu; Suzuki, Masahiro
no journal, ,
For the purpose of pulverizer selection for a dry recycled MOX powder with the size distribution suitable for a sintered density adjustment of MOX pellet, characterisity and performance of several types of pulverizer were evaluated, using quartzose sand and 0000 powder of sintered iron oxide were used as simulated raw material powder. Pulverized powder with a peak size at 40m is obtained, and it's possible to adjust peak grain-size in the small area by feed rate.
Kawaguchi, Koichi; Segawa, Tomoomi; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Ishii, Katsunori
no journal, ,
The reworking of out of specification pellets is required for the effective use of nuclear fuel material and for reduction of the plutonium inventory in fuel fabrication facilities. It is known that the sintering density of mixed oxide pellets can be controlled without a pore-former by controlling the amount and particle size of the recovered powder in the raw powder. The collision plate type jet mill was separated into the classifier and the mill chamber, and these modules were used independently. The peak position shifted to smaller sizes gradually over the five cycles of classification and pulverization. The collision plate type jet mill is a promising form of equipment to obtain particles with objective sizes as the main component of a powder.
Makino, Takayoshi; Yamamoto, Kazuya; Segawa, Tomoomi; Kawaguchi, Koichi; Iso, Hidetoshi
no journal, ,
The purpose of this study is to develop technology of the particle size adjustment of dry recovered powder of MOX pellets. Pulverization and classification experiments were conducted using simulated pellets obtained from materials having similar hardness and different density (specific gravity). We report that the results of pulverization and classification experiments in which experimental parameters were the clearance of the centrifugal classifier affecting the classification performance of the collision plate type jet mill.
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Fukasawa, Tomonori*; Fukui, Kunihiro*
no journal, ,
Japan Atomic Energy Agency has been used out of specification mixed oxide (MOX) pellets as a dry recovered powder for the effective use of nuclear fuel material in the MOX fuel fabrication process. The densities of the sintered MOX pellets can be controlled to about 85 %T.D. without adding pore former by adjusting the amount and the particle size of the dry recovered powder into the raw powder. It is required to adjust the particle size of the dry recovered powder to under 250 m, the influence of the operating parameters of the collision plate-type jet mill on the characteristics of pulverization and the influence of pulverized powders on sintering properties were evaluated. The clearance was narrowed, the pulverized powders were confirmed to be adjusted for the particle diameter of under 250 m, and the pellet prepared from the pulverized powder with density of about 85.0 %T.D. was obtained.
Yamamoto, Kazuya; Segawa, Tomoomi; Makino, Takayoshi; Kawaguchi, Koichi; Iso, Hidetoshi; Ishii, Katsunori
no journal, ,
no abstracts in English
Kawaguchi, Koichi; Yamamoto, Kazuya; Segawa, Tomoomi; Ishii, Katsunori; Makino, Takayoshi; Iso, Hidetoshi
no journal, ,
Pellet sintering density data obtained from experiments changing the mixing ratio of simulated raw material powder and simulated dry recovery powder from 10:0 to 0:10 were analyzed. A method of predicting the pellet sintering density from particle size distribution of the dry recovery powder and the mixing ratio was examined.
Yamamoto, Kazuya; Segawa, Tomoomi; Makino, Takayoshi; Kawaguchi, Koichi; Iso, Hidetoshi; Ishii, Katsunori
no journal, ,
no abstracts in English
Nakamichi, Shinya; Sunaoshi, Takeo*; Uno, Hiroki*; Yamada, Tadahisa*; Okumura, Kazuyuki
no journal, ,
no abstracts in English
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Yamamoto, Kazuya; Makino, Takayoshi; Okumura, Kazuyuki
no journal, ,
In previous studies, although a tendency for voids to form around dry recovered powder particles has been observed from the metallography of sintered pellets, it has been difficult to completely distinguish the areas derived from dry recovered powder particles from those derived from raw powder. In this study, for the purpose of clarifying the mechanism of the control of the pellet sintering density by dry recovered powder, and to identify the area in the sintered pellets derived from simulated dry recovered powder, (Ce,Zr)O
sintered pellets with zirconium oxide (ZrO) added as a tracer in CeO was milled and particle size adjusted to obtain (Ce,Zr)O simulated dry recovered powder was used as a parameter for the particle size distribution and the mixing ratio of CeO raw powder and simulated dry recovered powder to form and sintered pellets, and the microstructure of the pellets was evaluated.
Hayashizaki, Kohei; Hirooka, Shun; Sunaoshi, Takeo*; Nakamichi, Shinya; Murakami, Tatsutoshi
no journal, ,
no abstracts in English
Segawa, Tomoomi; Takashima, Hayato; Yamamoto, Kazuya; Ono, Takanori; Okumura, Kazuyuki; Kawaguchi, Koichi; Ishii, Katsunori
no journal, ,
In the pulverizing process of dry recycled powder on a mass production scale, pulverizing equipment with a classifying function is required to efficiently obtain a dry recycled powder that does not contain particles with excessive particle diameters. Since the maximum particle diameter tends to increase as the feed rate of raw material powder increases, focusing on the classification method, pulverization tests were performed on a mass production scale using collision plate-type jet mill and spiral jet mill with a classifying function. The results of these tests showed that the tendency of the maximum particle diameter to increase with increasing feed rate of the simulated raw material powders was different for each of the jet mill. This is considered to be attributable to differences in the characteristics of the classifying function of each mill.