为了准确测量燃料管燃耗和验证燃料管运行的正确性,保证反应堆安全运行、提高燃料的利用率和经济性,针对大直径燃料管相对燃耗测量存在的问题,根据燃料管结构设计了燃料管 γ 扫描测量系统.首先,用已知活度的10 mm137Cs标准点源验证了装置的可靠性和方法的可行性.然后,选取了同一燃料组件3种不同直径燃料管进行 γ 扫描,分别测量了燃料管径向和轴向相对燃耗分布,根据径向相对燃耗分布确定了燃料管阴阳面.最后,在燃料管阳面最大燃耗处进行燃料管轴向 γ 扫描,获得燃料管轴向相对燃耗分布,并对比各层燃料管相对燃耗大小.通过本方法确定的燃料管相对燃耗测量相对误差小于4％,实现了燃料管相对燃耗的精确测量,为其它类型燃料元件相对燃耗测量提供了一种新思维.%[Background] Fuel availability and economical efficiency are very important for nuclear reactor, measuring the relative burn-up of large-diameter fuel tubes is a challenge issue in nuclear engineering. [Purpose] This study aims to design aγ scanning system of fuel tubes based on the fuel tubes' structure to exactly measure the relative burn-up and verify the operating correctness of fuel tubes. [Methods] First of all, the reliability of the device and feasibility of the method was verified through a 10-mm standard137Cs point source. Then theγ scanning was carried out for three different diameter fuel tubes of the same fuel assembly to measure the relative burn-up distribution of fuel tubes separately in the radial and axial directions. The positive and cathode faces of fuel tubes were confirmed according to the relative burn-up distribution in the radial direction. Finally, the relative burn-up of fuel tubes in different layers was determined byγ scanning the fuel tube in the axial direction at the positive face with maximum burn-up.[Results] The measuring technique of relative burn-up of fuel tubes was realized with less than 4％ relative error. [Conclusion] Measuring technique of relative burn-up of fuel tubes was established by proposed approach, it provides a new way for the relative burn-up measurement of other fuel assembly.
展开▼
