• 제목/요약/키워드: $UO_3$

검색결과 315건 처리시간 0.027초

이중가연성 흡수 소결체의 균열 형성 및 UO$_2$-Gd$_2$O$_3$치밀화 속도에 미치는 첨가제 및 소결 분위기, 상승 속도의 영향 (Cracks in Sintered Duplex Burnable Absorber Pellet and Effect of Additives, Atmospheres and Heating Rate on the Densification of UO$_2$-Gd$_2$O$_3$)

  • 이영우;김건식;강기원;양재호;김종헌;송근우
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 2002년도 추계학술발표회요약집
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    • pp.275-275
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    • 2002

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가연성독극물로서 $SiB_4$를 첨가한 이산화우라늄의 소결특성 (Sintering Charateristics of $UO_2$ with Addition of $SiB_4$ as Burnable Poison)

  • 윤영수;윤용구;박지연;강영환
    • 한국세라믹학회지
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    • 제28권10호
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    • pp.767-776
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    • 1991

  • Effects of the additions of SiB4 as burnable poison to UO2 on the green density, densification, interdependence between density-grain growth and microstructure of sintered UO2 were studied. UO2 pellets were sintered in flowing hydrogen, at temperature 1200, 1350, 1500, and 168$0^{\circ}C$ for 3 hours and at 168$0^{\circ}C$ for 0, 1, 3, and 10 hours, respectively. Green densities were in the range of about 4.5~5.4 g/㎤, and decreased as the amount of SiB4 increased when green pellets were made by with use of a double action press at 1000 kg/$\textrm{cm}^2$. The density of sintered UO2 pellets was around 92~94% of the theoretical density and did not change significantly as the amount of SiB2 addition increased. However, the density of sintered pellets decreased with the increase in SiB4. The grain growth could be characterized in terms of two stages: Grain growth occurred with the increasing density in the first stage, whereas the second stage was characterized by the grain growth without increasing of density. A liquid phase was observed at grain boundaries and grain edges in the microstructure of sintered UO2 pellets with 5000 ppm and 10,000 ppm SiB4. This liquid, possible formed at about 168$0^{\circ}C$, did not enhance the shrinkage, but appeared to accelarate the grain growth. It seems that the second stage grain growth was due to the presence of pressurized insoluble trapped gas in isolated pores.

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