Search

Your search keyword '"Choi Cheong-Song"' showing total 29 results
Start Over Author "Choi Cheong-Song"
29 results on '"Choi Cheong-Song"'

16. Crystallization characteristics of ammonium uranyl carbonate (AUC) in ammonium carbonate solutions

Author

Chang In-Soon, Kim Tae-Joon, Jeong Kyung-Chai, Choi Cheong-Song, and Park Jin-Ho

Subjects
Ammonium carbonate, Nuclear and High Energy Physics, Mole ratio, Economies of agglomeration, Inorganic chemistry, Mixing (process engineering), Ammonium uranyl carbonate, law.invention, chemistry.chemical_compound, Nuclear Energy and Engineering, chemistry, Uranyl nitrate, law, Pellet, General Materials Science, Crystallization, Nuclear chemistry
Abstract

Ammonium carbonate solutions with an excessive amount of NH3 were produced in a commercial AUC (ammonium uranyl carbonate) conversion plant. In this study the AUC crystals, precipitated with uranyl nitrate and ammonium carbonate solutions prepared in the laboratory, were characterized to determine the feasibility of recycling ammonium carbonate solution. The AUC crystals were easily agglomerated with the increasing concentration of CO32− and mole ratio of NH 4 + CO 3 2− in ammonium carbonate solution. Effects of a mixing system for the solution in the AUC crystallizer and the feed location of the solution on the agglomeration of AUC crystals were also studied along with the effects of agglomerated AUC powders on UO2 powders. Finally, the feasibility of manufacturing UO2 fuel with a sintered pellet density of 10.52 g/cm3, using the AUC powders generated in this experiment, was demonstrated.

Published
1994
Full Text
View/download PDF

27. A photo-induced dissolution of UO2 sintered pellets in a simulated solution.

Author

Kim, Eung-Ho, Choung, Won-Mung, Kim, Yeon-Ku, Park, Jin-Ho, Yoo, Jae-Hyung, and Choi, Cheong-Song

Abstract

The objective of this study is to improve the established dissolution technique of UO2 target by using a photochemical reaction. Photo-dissolution tests of UO2 sintered powder and pellets were carried out in a simulated nitric acid solution at about 50 °C under UV irradiation. The simulated solution consists of 2 M nitric acid containing elements such as Cs, Sr, Zr, Ru, Mo and Nd. The light source is a Hg-lamp emitting 254 nm wavelength. As results, in the dark reaction, UO2 sintered pellets were hardly dissolved, whereas UO2 was rapidly dissolved after 7 hours of dissolution time in the UV irradiation. The very low dissolution rate in the dark reaction was due to surface characteristics of sintered pellets: UO2 sintered pellet is very dense and has extremely low specific surface area. However, the dissolution rate of UO2 sintered pellet was considerably increased in the simulated solution under UV irradiation. This was attributed to the fact that ruthenium and molybdenum ions in the simulated solution could accelerate the dissolution of UO2 under UV irradiation. Additionally, when the pulverized sintered UO2 powder was used, the dissolution rate of UO2 increased more rapidly than that of UO2 sintered pellet. [ABSTRACT FROM AUTHOR]

Published
2000
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results