유리탄소의 동시증착에 의한 TRISO 피복입자의 ZrC 코팅층 미세구조와 화학양론비 제어 |
고명진, 김대종, 박지연, 조문성1, 김원주 |
한국원자력연구원 원자력재료개발부 1한국원자력연구원 차세대핵연료개발부 |
Microstructure of ZrC Coatings of TRISO Coated Particles by Codeposition of Free Carbon and Control of Stoichiometry |
Myung-Jin Ko, Daejong Kim, Ji Yeon Park, Moon Sung Cho1, Weon-Ju Kim |
Nuclear Materials Division, Korea Atomic Energy Research Institute 1HTGR Fuel Technology Development Division, Korea Atomic Energy Research Institute |
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ABSTRACT |
TRISO coated particles with a ZrC barrier layer were fabricated by a fluidized-bed chemical vapor deposition (FBCVD) method for a use in a very high temperature gas-cooled reactor (VHTR). The ZrC layer was deposited by the reaction between $ZrCl_4$ and $CH_4$ gases at $1500^{circ}C$ in an $Ar+H_2$ mixture gas. The amount of free carbon codeposited with in ZrC was changed by controlling the dilution gas ratio. Near-stoichiometric ZrC phase was also deposited when an impeller was employed to a $ZrCl_4$ vaporizer which effectively inhibited the agglomeration of $ZrCl_4$ powders during the deposition process. A near-stoichiometric ZrC coating layer had smooth surface while ZrC containing the free carbon had rough surface with tumulose structure. Surface roughness of ZrC increased further as the amount of free carbon increased. |
Key words:
TRISO, VHTR, ZrC, Free carbon, Stoichiometry |
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