화학공학소재연구정보센터
학회 한국재료학회
학술대회 2005년 가을 (11/10 ~ 11/11, 한양대학교)
권호 11권 2호
발표분야 에너지환경재료
제목 단롤 주조법에 의한 광폭의 U-7wt.%Mo 합금 박판의 제조 및 특성
초록 Monolithic fuel has been investigated as a very-high-density fuel candidate for high-performance research reactors since 2000. Excellent in-reactor results have been obtained from the irradiation of mini-plates containing monolithic U-Mo fuel elements with a uranium density of 15.6 g/cm3. If an economically viable manner of fabricating the monolithic U-Mo fuel elements is developed, and if the preliminary irradiation tests are confirmed, this fuel holds the promise of enabling a LEU operation of all the existing and future research reactors in combination with an unprecedented performance.
As the monolithic U-Mo fuel specimens irradiated in the RERTR-4 were fabricated at a laboratory scale, not at a commercialized scale, by the cold-rolling method due to some problems in the foil quality, productivity and economic efficiency, attention has shifted to the development of an alternative technology. U-7wt.%Mo foils for a monolithic fuel have been fabricated at KAERI by a single roll casting method. The continuous U-Mo foils have been obtained through a rapid cooling directly from a melt. The fabrication of the U-Mo foil by a single roll casting method has been carried out.
U-7wt.%Mo ingots, melted and cast with a proportioned charge of depleted uranium lumps (99.9 % pure) and molybdenum button (99.7% pure), were charged and induction-melted in a high-temperature-resistant ceramic nozzle. The superheated molten U-Mo alloy was discharged through a small slot in the nozzle onto a rotating cooling-roll under the condition where the slot was located close to the cooling roll. The U-Mo foils were rapidly cooled by contact with the rotating roll driven by an electric motor in an inert atmosphere, so that the fine crystalline grains of the U-Mo foils with the meta-stable -U phase are formed. The rapidly solidified foil was collected in a container.
Polycrystalline U-7wt.%Mo foils with a width of about 50 mm and a thickness ranging from 100 to 250 microns were continuously fabricated, by adjusting the process parameters of a single roll casting method apparatus. The U-Mo foils had a good roughness on the surface, with a few impurities. The U-7wt.%Mo foils had fine and uniform poly-crystalline cells below about 30 microns in size with the gamma U phase. It is expected that a monolithic fuel with the U-Mo foils will show a breakaway swelling behavior but a stable in-reactor behavior during an irradiation. The fabrication of U-Mo foils by the cooling-roll casting method could be suggested as an alternative process for the fabrication of the monolithic U-Mo fuel for research reactors.
저자 김기환, 김창규
소속 한국원자력(연)
키워드 U-7wt.%Mo foil; U-Mo alloy; Single cooling-roll; Nuclear fuel
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