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Segawa, Tomoomi; Fukasawa, Tomonori*; Yamada, Yoshikazu; Suzuki, Masahiro; Yoshida, Hideto*; Fukui, Kunihiro*
Proceedings of Asian Pacific Confederation of Chemical Engineering 2015 (APCChE 2015), 8 Pages, 2015/09
A mixed solution of uranyl nitrate and plutonium nitrate is converted to MOX raw powder by the microwave heating de-nitration method in nuclear reprocessing. Copper oxide synthesized by heating de-nitration was used as a model for the de-nitration process. The microwave heating method (MW) and infrared heating method (IR) were used, and how they and their heating rate influence the obtained particle morphology and size were investigated. The particles obtained by the MW and IR were sufficiently similar in the surface morphology and the mass median diameter was decreased by the increased heating rate. The mass median diameters by the MW were the heating rate and smaller than those obtained by IR. The particle size distribution of the particle obtained by the MW was broader than that by the IR. The relationship of the temperature distribution and particle size distribution by the MW was discussed by the numerical simulation.
Haraga, Tomoko; Kameo, Yutaka; Nakashima, Mikio
Bunseki Kagaku, 55(1), p.51 - 54, 2006/01
Times Cited Count：4 Percentile：14.14(Chemistry, Analytical)A relatively large quantity of sample solutions have to be prepared for radiochemical analysis of solidified products yielded by plasma melting treatment of non-metallic radioactive wastes. In order to dissolve the solidified products sample rapidly, dissolution method with microwave heating devices was applied. In a conventional method only by external heating with various mixtures of acids (HNO
, HF, HClO
and H
SO), a 0.1 g amount of the sample was dissolved with difficulty. However, applying the microwave assisted dissolution method, a 1 g amount of the sample was completely dissolved in a shorter time. Thereby the time for dissolution procedures was shortened less than a one-tenth. The present dissolution method was successfully applied to the blast furnace slag as a reference material to determine main elements with good precision.
Journal of Nuclear Materials, 254, p.14 - 21, 1998/00
Times Cited Count：16 Percentile：75.89(Materials Science, Multidisciplinary)no abstracts in English
; ; Ogawa, Toru
JAERI-Tech 96-026, 21 Pages, 1996/06
no abstracts in English
; ; Ogawa, Toru
JAERI-Tech 94-010, 33 Pages, 1994/07
no abstracts in English
Kato, Yoshiyuki; Tanigawa, Masafumi; Takahashi, Naoki; Kurita, Tsutomu
no journal, ,
Plutonium nitrate and uranyl nitrate mixed solution is co-converted to MOX powder by the microwave heating method developed by JAEA. The appropriate placement in the microwave oven of the specimen is very important to improve the energy-saving performance in this conversion process. However, much labor is required to perform the plutonium nitrate and uranyl nitrate mixed solution heating examination by the microwave and the electromagnetic field analysis in the microwave oven. Therefore an electrical characteristic carried out a heating examination using the similar nitric acid solution with plutonium nitrate and nitric acid uranyl solution. Furthermore, the electromagnetism properties in the oven tried an application by a height pattern theory used for an antenna circuit. The experimental results could almost be explained by the numerical analyses.
Chonan, Fuminori*; Abe, Yutaka*; Yuasa, Tomohisa*; Kaneko, Akiko*; Segawa, Tomoomi; Yamada, Yoshikazu
no journal, ,
In a reprocessing process of nuclear fuel cycle, an uranium-plutonium mixed oxide (MOX) raw powder is converted from a mixture solution of uranyl nitrate and plutonium nitrate by the microwave heating denitration method (MH method). The MH method is applied to remove water and nitric acid from a metallic nitrate solution, and a metallic oxide is obtained. In order to improve the efficiency of MH method, optimizing the equipment and conditions is needed to prevent flushing of a mixture solution during microwave heating. In our group, we have been studied that the influence of height of supporter which placed under the mixture solution in the vessel on its heating phenomena. Also we have been analyzed simulation of electromagnetic field during microwave heating in microwave oven. From those results, we considered the appropriate height of supporter in the oven. It was clarified that height of supporter was one of the important parameter for the efficiency of microwave heating.
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Nagakawa, Genta*; Tamaru, Ayaka*; Fukasawa, Tomonori*; Ishigami, Toru*; Fukui, Kunihiro*
no journal, ,
Microwave heating in combination with an external heating source has been used to improve powder properties by compensating for heat transfer losses. However, the external heating source in the microwave irradiation field may degrade the heating elements. A hybrid heating method has been developed to use composite ceramic jacket prepared by adding carbon nanotube (CNT) to alumina. To evaluate the effect of CNT-containing alumina composite ceramic jacket (CNT jacket), experiments were implemented. In both copper nitrate solution and nickel nitrate solution, the time to reach the maximum temperature was earlier when the CNT jacket was used than when the alumina jacket was used. The temperature of the nickel nitrate solution was kept at the maximum temperature when the CNT jacket was used, while the temperature tended to decrease after reaching to 280
C when the alumina jacket was used. The hybrid heating method using the CNT jacket can obtain metal oxides.
