변형 Sol-Gel 방법을 이용한 고온가스로 핵연료 미세구입자 제조 |
정경채, 김연구, 오승철, 조문성 |
한국원자력연구원 피복입자 핵연료기술개발과제 |
HTGR Nuclear Fuel Microsphere Preparation Using the Modified Sol-Gel Method |
Kyung-Chai Jeong, Yeon-Ku Kim, Seung-Chul Oh, Moon-Sung Cho |
HTGR Nuclear Fuel Technology Development Division, KAERI |
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ABSTRACT |
$UO_2$ microsphere particles, core material of HTGR(High Temperature Gas Reactor) nuclear fuel, were prepared using by the GSP(Gel Supported Precipitation) method which is a modified-method of the wet sol-gel process. The spherical shape of initial liquid ADU droplets from the vibration nozzle system was continuously kept till the conversion to the final $UO_2$ microsphere. But the size of a final $UO_2$ microsphere was shrunken to about 25% of an initial ADU droplet size. Also, we found that the composition of dried-ADU gel particles was constituted of the very complicated phases, coexisted the U=O, C-H, N-H, N-O, and O-H functional groups by FT-IR. The important factors for obtain the no-crack $UO_2$ microsphere during the thermal treatment processes must perfectly wash out the remained-$NH_4NO_3$ within the ADU gel particle in washing process and the selections of an appropriate heating rate at a suitable gas atmosphere, during the calcining of ADU gel particles, the reducing of $UO_3$ particles, and the sintering of $UO_2$ particles, respectively. |
Key words:
HTGR, Fuel, Sol-gel, $UO_2$ microsphere |
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