• Title/Summary/Keyword: 건식저장

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The Test for Verifying a Tip-Over Analysis of a Dry Storage Cask (건식저장용기에 대한 전복해석의 검증시험)

  • Kim Dong-Hak;Seo Ki-Seog;Lee Ju-Chan;Cho Chun-Hyung;Jang Hyun-Kee;Choi Byung-Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.3
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    • pp.245-253
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    • 2006
  • A test of the 1/3 scale model was conducted to verify the tip-over analysis of a dry. concrete storage cask under a hypothetical accident condition. The tip-over analysis was executed using the velocity at each point as the initial conditions of the model just before the impact. The initial velocity was determined from the initial angular velocity, which would make the equivalent kinetic energy to the potential energy. To confirm the structural integrity of the canister, the visual testing and the non-detective testings such as Liquid Penetrant testing and Ultrasonic Testing were conducted. The lid of a storage cask was plastically deformed near the impact point. The structural integrity of storage cask was maintained. To verify the tip-over analysis the strains and the accelerations acquired by the tip-over test were compared with those by the analyses. The results of the analysis were larger than the test results about two times.

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Changes in the pasting properties and fatty acid values of dry-milled rice flour at different storage temperatures (저장 온도에 따른 건식제분용 쌀가루의 호화특성 및 지방산가 변화)

  • Jo, Youngje;Chun, Areum;Sim, Eun-Yeong;Park, Hye-Young;Kwak, Ji-Eun;Kim, Mi-Jung;Lee, Choon-Ki
    • Korean Journal of Food Science and Technology
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    • v.52 no.4
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    • pp.396-402
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    • 2020
  • In order to investigate the changes in the quality attributes during the storage of dry-milled rice flour, two flour samples were obtained from two rice varieties (Hangaru (HG), Samkwang (SK)). These samples were stored at 4℃ and room temperature, respectively, and we analyzed the initial rice flour moisture content and chemical properties. The changes in the rice flour pasting and quality properties during storage were measured for 12 months. Our results showed that HG exhibited better pasting properties than SK, while the fat acidity of HG rapidly increased at room temperature, resulting in short shelf-life. However, the low-temperature (4℃) storage of dry-milled rice flour could reduce the change in the free fatty acid values of both samples. Therefore, low-temperature storage seems to contribute not only to an increased rice flour shelf-life by reducing the fatty acid value changes but also to a reduction in the changes in pasting properties.

$UO_2$ 소결펠렛의 건/습식 산화반응 연구

  • 김익수;이원경;신희성;신영준;노성기
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05a
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    • pp.805-805
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    • 1995
  • 핵연료저장시설의 화재 등 극단적인 사고조건하에서 $UO_2$ 소결펠렛의 습식산화와 건식산화에 대한 연구를 수행하였다. 손상된 지르칼로이 피복관 속의 $UO_2$ 소결펠렛을 산성분위기의 습윤조건하에서 산화시킬 때의 $UO_2$ 펠렛의 산화속도는 IDR(mg/$\textrm{cm}^2$.min) = 1.55 [H$^{+}$]$^{1.21}$ 로 나타났다. 또한 습윤조건하에서 $UO_2$ 분말에 알카리 및 알카리 토금속 산화물, 그리고 백금족 및 회토류 산화물 등과 같은 불순물들이 존재할 때의 산화속도를 조사하였으며 이들에 대한 영향도 관찰하였다. 핵연료저장시설의 가상화재를 바탕으로 한 400~$700^{\circ}C$의 온도범위에서, 피복관이 씌워진 $UO_2$ 소결펠렛의 건식산화반응을 조사한 바 $UO_2$ 소결펠렛은 산화초기에 U$_4$O$_{9}$ 또는 U$_3$O$_{7}$ 등의 중간상 형성에 따른 3-4%의 부피축소에 의해 결정립계 균열이 일어나고, $600^{\circ}C$ 이하에서는 온도증가에 따라 중간상에서 U$_3$O$_{8}$ 상으로의 상변화에 의한 부피팽창으로 피복관의 변형과 함께 산화속도의 가속을 발견할 수 있었고, $600^{\circ}C$ 이상에서는 핵연료소자의 소성변형으로 인한 산화속도의 지연을 발견할 수 있었다. 또한 $UO_2$ 펠렛의 건식산화거동은 기체-고체 반응시의 전형적인 형태인 shrinking core model에 잘 적용될 것으로 판단되었다.

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