• 제목/요약/키워드: Nuclear fuel ($UO_2$)

검색결과 213건 처리시간 0.027초

Microstructural Changes of AlOOH Doped $UO_2$ Pellet during the Annealing Process

  • Hosik Yoo;Lee, Shinyoung;Lee, Seungjae;Kwenho Kang;Kim, Hyoungsu
    • The Korean Journal of Ceramics
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    • 제6권3호
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    • pp.209-213
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    • 2000

  • Microstructural changes of AlOOH doped UO$_2$pellet after annealing up to 216h have been observed and they were compared with those of the standard pellet. Grain and pore size of UO$_2$pellet increased with the addition of AlOOH and its effect was still validated during annealing. Densification rate was reduced by the addition of AlOOH and it was attributed to coarsened pores with spherical shape. Grain and pore growth was stopped and density increase was the least after 144h of annealing. The variation of pore size resulting from annealing has a linear relationship with that of grain size.

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Measurement of Melting Temperatures of $UO_2,\;(U,Gd)O_2\;and\;(U,Er)O_2$ Fuels

  • Kang Ki Won;Yang Jae Ho;Kim Keon Sik;Kim Jong Hun;Lee Young Woo;Song Kun Woo
    • Nuclear Engineering and Technology
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    • 제36권1호
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    • pp.104-111
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    • 2004

  • The melting temperatures of $UO_2,\;UO_2-6wt\%Gd_{2}O_3,\;UO_2-12wt\%Gd_{2}O_3,\;UO_2-2wt\%Er_{2}O_3,\;and\;UO_2-4wt\%Er_{2}O_3$ fuels were measured. Fuel materials were loaded in a tungsten capsule of which shape met the black body condition. The melting temperature was measured by the thermal arrest method during heating of the capsule in an induction furnace. The measured melting temperature of $UO_2$ fuel was $2815{\pm}20^{\circ}C$. The solidus and liquidus temperatures of $UO_2-Gd_{2}O_3\;and\;UO_2-Er_{2}O_3$ had also been measured, and it was observed that the solidus temperatures of them were lower than the liquidus temperature by $15{\sim}25^{\circ}C$. Measured melting temperatures of $UO_2,\;UO_2-Gd_{2}O_3\;and\;UO_2-Er_{2}O_3$ fuels were as follows:

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노내 손상 핵연료의 산화거동 및 핵연료 산화가 핵분열기체 방출에 미치는 효과 (Oxidation Kinetics of $UO_2$ Pellets in Defective Fuel Rods and Its Effect on Fission Gas Release)

  • Koo, Yang-Hyun;Sohn, Dong-Seong;Yoon, Young-Ku
    • Nuclear Engineering and Technology
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    • 제26권1호
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    • pp.90-99
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    • 1994

  • 손상 핵연료에서 발생하는 주요한 현상중의 하나는 수중기의 분해로 갭에 존재하는 산소에 의해 $UO_2$ 가 $UO_{2+}$x/로 산화되고, 이로 인해 결정립내에서의 핵분열기체 확산계수가 증가하여 결과적으로 핵분열 기체의 방출이 증대하는 현상이다. 본 논문은 일반적인 원자로 운전 조건하에서 원자로 및 손상 핵연료의 운전조건을 고려하여 소결체의 산화거동을 모사하고 이를 바탕으로 소결체 산화가 핵분열기체의 방출 중대에 미치는 영향을 분석하였다. 소결체 산화거동은 갭에는 150기압의 포화된 순수한 수증기만이 존재한다는 가정하에 분석하였고, 산화에 의한 핵분열기체의 방출 증대 효과를 정량적으로 분석하기 위해 방출중대 인자를 도입하였다. 실험 치와 비교한 결과 방출증대 인자는 소결체 산화에 의한 핵분열기체의 방출증대 효과를 잘 예측하였다.

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