• 제목/요약/키워드: UO2

검색결과 620건 처리시간 0.024초

HIGH BURNUP FUEL TECHNOLOGY IN KOREA

  • Song, Kun-Woo;Jeong, Yong-Hwan;Kim, Keon-Sik;Bang, Je-Geon;Chun, Tae-Hyun;Kim, Hyung-Kyu;Song, Kee-Nam
    • Nuclear Engineering and Technology
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    • 제40권1호
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    • pp.21-36
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    • 2008

  • High bum-up fuel technology has been developed through a national R&D program, which covers key technology areas such as claddings, $UO_2$ pellets, spacer grids, performance code, and fuel assembly tests. New cladding alloys were developed through alloy designs, tube fabrication, out-of-pile test and in-reactor test. The new Zr-Nb tubes are found to be much better in their corrosion resistance and creep strength than the Zircaloy-4 tube, owing to an optimized composition and heat treatment of the new Zr-Nb alloys. A new fabrication technology for large grain $UO_2$ pellets was developed using various uranium oxide seeds and a micro-doping of Al. The uranium oxide seeds, which were added to $UO_2$ powder, were prepared by oxidizing and heat-treating scrap $UO_2$ pellets. A $UO_2$ pellet containing tungsten channels was fabricated for a thermal conductivity enhancement. For the fuel performance analysis, new high burnup models were developed and implemented in a code. This code was verified by an international database and our own database. The developed spacer grid has two features of contoured contact spring and hybrid mixing vanes. Mechanical and hydraulic tests showed that the spacer grid is superior in its rodsupporting, wear resistance and CHF performance. Finally, fuel assembly test technology was also developed. Facilities for mechanical and thermal hydraulic tests were constructed and are now in operation. Several achievements are to be utilized soon by the Korea Nuclear Fuel and thereby contribute to the economy and safety of PWR fuel in Korea

  • https://doi.org/10.5516/NET.2008.40.1.021 인용 PDF KSCI

膈膜電解槽와 水銀陰極에 依한 Uranyl 溶液의 電解還元 (A Study of Mercury-Cathode Membrane Cells for the Electrolytic Reduction of Uranyl Solutions)

  • 김재원
    • 대한화학회지
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    • 제6권1호
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    • pp.1-9
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    • 1962

  • 高純度의 $UO^2$ pellets나 或은 $UF_4$를 얻는 것을 目標로 하여 그 計劃의 一郡으로 純粹한 $UO_2^{++}$ 溶液을 $U^{+4}$溶液으로 電解還元하는 方法을 實驗하였다. 現在 實施되고 있는 方法으로서는 純粹한 $UO_3$粉末을 水素 或은 ADU(ammonium diuranate)를 熱分解하여 生成되는 分解된 암모니아로서 600 내지 900$^{\circ}C$ 還元하거나 혹은 복잡한 構造를 가진 Excer cell로서 濕式電解하는 方法들이 있다. 이 報告는 從來의 Excer cell을 改造하여 水銀陰極과 陽이온 交換樹脂의 膈膜 및 鉛陽極으로 구성되는 간단한 電解裝置로서 $UO_2^{++}$ 溶液을 連續的으로 電解시켰을 때 가장 適合한 電解槽의 構造, 電解液의 溫度, 電解液의 種類와 濃度 또 各 流量과 電流密度에 따르는 電流效率, 電解槽電壓等을 測定한 結果를 記錄하고 電解反應을 說明한 것이다. 實驗結果에 依하면 電解槽는 水平式으로 하여 길이와 폭의 比가 20對 1이고 電解液은 還元에 所要될 때 理論量 以上의 遊離黃酸이 共存하는 可及的 高農度의 $UO_2SO_4$ 溶液과 그에 比例하는 電流密度를 使用하여 電解함으로써 單一過程의 電解에 依하여 $UO_2^{++}$ 를 $U^{+4}$로 80 내지 95%의 電流效率로서 還元시킬 수 있다는 것을 알았다.

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