• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.408-409
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• 2005

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.11a
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• pp.141.1-141.1
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• 2004

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.614-615
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• 2018

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.267-267
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• 1999

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.149.1-149
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• 2002

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.1-15
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• 2016

For a long time, a top priority in the nuclear industry was the safe, reliable, and economic operation of light water reactors. However, the development of accident-tolerant fuel (ATF) became a hot topic in the nuclear research field after the March 2011 events at Fukushima, Japan. In Korea, innovative concepts of ATF have been developing to increase fuel safety and reliability during normal operations, operational transients, and also accident events. The microcell $UO_2$ and high-density composite pellet concepts are being developed as ATF pellets. A microcell $UO_2$ pellet is envisaged to have the enhanced retention capabilities of highly radioactive and corrosive fission products. High-density pellets are expected to be used in combination with the particular ATF cladding concepts. Two concepts-surface-modified Zr-based alloy and SiC composite material-are being developed as ATF cladding, as these innovative concepts can effectively suppress hydrogen explosions and the release of radionuclides into the environment.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.265-270
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• 1996

The temperature distribution in the pellet was obtained from beginning the general heat conduction equation. The thermal conductivity of pellet used the SIMFUEL data that made clear the effect of burnup on the thermal conductivity degradation. Since the pellet rim acts as the thermal barrier to heat flow. the pellet was subdivided into several rings in which the outer ring was adjusted to play almost the same role as the rim. The local burup in each ring except the outer ring was calculated from the power depression factor based on FASER results. whereas the rim burnup at the outer ring was achieved by the pellet averaged burnup based on the empirical relation. The rim changed to the equivalent Xe film so the predicted temperature shooed the thermal jump across the rim. The observed temperature profiles depended on linear heat generation rate. fuel burnup. and power depression factor. The thermal conductivity degradation modelling can be applied to the fuel performance code to high burnup fuel,

• Resources Recycling
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• v.11 no.4
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• pp.3-10
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• 2002

The characteristics of dry and wet milled powder prepared by 1 cycle OREOX (oxidation and reduction of oxide fuels) treatment were investigated using the simulated spent fuel pellet. Sintered pellets simulating spent nuclear fuel burned in reactor were fabricated from $UO_2$ powder using as a starting material in fabrication of nuclear fuel. The 1 cycle OREOX-treated powder was prepared by only one path of oxidation md reduction of the simulated pellet. Powder having average particle size of less than 1 $\mu\textrm{m}$ could be easily obtained by dry milling, but not be achieved by wet milling. And, specific surface area of dry milled pow-der was higher than that of wet milled powder. Dry milled powder formed loose agglomerate, while wet milled powder showed the shape of irregular and angular particles. Dry milled powder provided higher green density, resulting in higher sintered density of higher than 95% TD and average grain size of larger than 8 $\mu\textrm{m}$ satisfying the standard specification of sintered pellets.

• Journal of Powder Materials
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• v.14 no.1 s.60
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• pp.8-12
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• 2007

The effect of a CAM (Continuous Attrition Mill) treatment on the sinterability of ex-ADU $UO_2$ powder was investigated. As the cycles of a CAM increased, the apparent density, specific surface area and O/U of the milled powder increased, but there particle sizes decreased. However the sintered density of the $UO_2$ pellet decreased as the cycles of the CAM increased. It is considered that the decrease of the sintered density is due to the formation of $U_3O_8$, which was produced by a CAM mechanism.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.406-407
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• 2005

사용후핵연료 차세대관리공정에서는 $UO_2$ 펠렛을 균질화된 $U_{3}O_8$의 분말 형태로 되어야만 금속 전환공정에서 반응효율을 높일 수 있다. 본 연구에서는 실증용 건식분말화 장치에서 분말의 비산을 방지하면서 산화 효율을 최대한 높일 수 있는 최적 조건을 찾는데 있다고 할 수 있다. 본 연구의 실험에서 $UO_2$ 펠렛(약 90 g)에 유량별 공정 변수를 주어 최적화된 산화 조건을 조사하였다. 그 결과, $500^{\circ}C$ 에서 유량은 이론 산화량의 2배(1640 cc/min)의 조건에서 최적의 산화 효율을 보여주었다. 따라서 본 연구에서 실증용 건식분말화 장치의 비산을 방지하면서 산화 효율을 최대한 높일 수 있는 최적 유량을 결정하였다.