通过测量模拟样品中236U与238U原子个数比估算燃耗的探索研究

自然界中²³⁶U与²³⁸U原子个数比约10^-14，不同反应堆类型及核燃料辐照情况辐照后的核材料中²³⁶U与²³⁸U原子个数比不同，一般为天然²³⁶U与²³⁸U原子个数比的10⁷～10¹¹倍。通过测量环境样品中的²³⁶U与²³⁸U原子个数比可探知取样点附近进行过的辐照活动、环境污染的来源及对应核燃料的燃耗。本研究使用配制的模拟样品，建立了多接收电感耦合等离子质谱（MC-ICP-MS）技术测定²³⁶U与²³⁸U原子个数比的方法以及估算核燃料燃耗的工作方案，并与其他燃耗计算方法比较，燃耗的相对偏差约10%。

Primary Study on Burnup Estimation of Irradiated Uranium by Determining Ratio of 236U and 238U Atom Number in Simulated Samples

The ratio of ²³⁶U and ²³⁸U atom number is different depending on the type of reactor and the status of irradiation of nuclear materials, which is usual 10⁷-10¹¹ times than that in nature. The irradiation activity near sampling spots, the source of irradiation contamination, and the burnup of spent nuclear fuel can be explored by measuring ratio of ²³⁶U and ²³⁸U atom number in environmental samples. The method of measuring ratio of ²³⁶U and ²³⁸U atom number in simulated samples by MC-ICP-MS and the working schedule for estimating burnup of spent nuclear fuel have been established. Compared with the other methods, the relative deviation of burnup is about 10%.