二氧化铀粉末和芯块铀含量及氧铀原子比的测定

Determination of Uranium and Oxygen/uranium Ratio in Uranium Dioxide Powder and Pellets

二氧化铀(UO2)芯块氧铀原子比是影响其在反应堆内热能释放的一个重要参数,准确测定氧铀原子比对了解铀氧体系及控制燃料生产是极其重要的。本方法是依据国际标准ISO 12795《重量、杂质校正法测定UO2芯块铀含量及氧铀原子比》,在室温静态下称取试样氧化前后的质量,进行水分及杂质含量校正后根据其质量变化计算铀含量和氧铀原子比,对于5 g以上的UO2芯块试样氧铀原子比,该方法的相对标准偏差优于0.1%;对于8 g以上的UO2粉末氧铀原子比,相对标准偏差优于0.2%。

The oxygen /uranium ratio of uranium dioxide pellets is an important parameter of heat energy releasing in reactor. Accurate measurement of oxygen/uranium ratio is extremely important for understand uranium-oxygen system and controlling nuclear fuel production. This method was based on ISO12795 Determination of uranium and oxygen/uranium ratio by gravimetric method with impurity correction in uranium dioxide powder and pellets. Weigh the quality of the samples before and after oxidation at room temperature. Calculate the uranium content and oxygen/uranium ration with moisture and impurities correction according to the quality change. For the uranium dioxide pellets the weight of which is more than 5 g,the oxygen/uranium ration relative standard deviation of this method is better than 0. 1%; For the uranium dioxide powder the weight that is more than 8 g,the oxygen/uranium ration relative standard deviation of this method is better than 0. 2%.