基于双能γ射线吸收法的U-Zr弥散燃料芯体铀均匀性检测技术

Detecting Technique for Uranium Distribution Uniformity of Dispersion Uranium-Zirconium Fuel Core Based on Dual Energy Gama-Ray Transmission

双能γ射线吸收法是一种检测弥散燃料元件铀均匀性的新方法。实验选用75Se多能谱γ射线源中的2个分支比较高的能量136、264 ke V进行测试;选用高纯锗(HPGe)探测器进行γ射线探测。根据U、Zr的γ射线衰减系数差异在136 ke V能量下远大于264 ke V能量的特性,测定U-Zr弥散燃料芯体中的U、Zr含量和均匀性。实验使用有机玻璃瓶罐装U粉末、Zr粉末制作标准样进行吸收系数标定,使用"迭代法"对方程进行求解。最终结果显示测试相对精度为±5%,满足大多数工程应用要求。

Dual energy gama-rays transmission method is a new method for the detection of uranium distribution uniformity of dispersion fuel core. The 136 keV and 264 keV high energy of Se-75 radiation source is chosen for the test. HPGe is detected by Gama-ray detector. Under the energy of 264 keV ,U and Zr＇s gamma ray attenuation coefficient, which is far greater than the coefficient at the energy of 136 keV, the content and uniformity of U and Zr in dispersion fuel core were determined. Plexiglass bottles contain Uranium and Zirconium powder are used as criterion specimen for the attenuation measurement and iterative method is used for solve the equation. The results present that the relative errors of detecting system is less than 5%, well meet the requirements.