Gamma Decomposition and Powder Formation of 纬-U8Mo Nuclear Fuel Alloys via a Hydration鈥揇ehydration Process

详细信息    查看全文

• 作者：F谩bio Branco Vaz de Oliveira ; Adriano Michael Bernardin ; Humberto Gracher Riella
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：June 20, 2012
• 年：2012
• 卷：51
• 期：24
• 页码：8237-8245
• 全文大小：378K
• 年卷期：v.51,no.24(June 20, 2012)
• ISSN：1520-5045

文摘

Gamma uranium鈥搈olybdenum alloys have been considered as the fuel phase in plate type fuel elements for material test reactor (MTR) reactors, mainly owing to their acceptable performance under irradiation and metallurgical processing. Regarding their usage as a dispersion phase in aluminum matrix, it is necessary to convert the as cast structure into powder, and one of the techniques considered for this purpose at IPEN/CNEN (Brazil) is by means of the HDH (hydration鈥揹ehydration) reactions. This paper shows that, under specific conditions of heating and cooling, hydration鈥揹ehydration is sometimes unnecessary, and 纬UMo fragmentation occurs in a nonreaction predominant mechanism, as shown by the curves of hydrogen absorption/desorption by the gamma uranium鈥搈olybdenum alloys as a function of time and temperature. Our focus was on the experimental results presented by the addition of 8% weight molybdenum. Subsequent to their production by induction melting, samples of the alloys were thermally treated under a constant flow of hydrogen for temperatures varying from 500 to 600 掳C and for time of 2 to 4 h. The curves relating mass incorporation and time for the above-mentioned temperatures were obtained, and the results were related to the fragmentation. The main conclusion is that, even without a massive hydration鈥揹ehydration process, the samples could be fragmented under specific conditions of thermal treatment under the thermal shock phase of the experiments and that there is a strong correlation between absorption and the rate of gamma decomposition or the gamma phase stability of the alloy. In addition, a suggested value of 568.4 掳C was obtained for the maximum rate of gamma decomposition, which can also be related to its eutectoid transformation temperature.