137Cs源燃料棒芯块间隙检测装置设计

摘要

A new fuel rod inter-pellets gaps inspecting equipment with 137Cs radioactive source was designed.Comparing with the old equipment with 241Am source, this gaps inspecting equipment can distinguish annular, solid pellets, pellet-cushion, spring and support tube effectively.The speed of inspecting equipment can reach to 6 m/min with 1.5Ci 137Cs source, measuring precision of pellet up to 0.13 mm, fuel rod length up to 4 mm/1m, with 95% confidence.The inspecting equipment was working stably and fulfill the inspecting requirements.%设计了一种使用137Cs γ放射源检测新型燃料棒内芯块间隙的装置.该装置除具备241Am源检测装置功能外,还可清晰辨别实心芯块和环形芯块区域,以及辨别燃料棒内的芯块垫、弹簧、支撑管等.使用1.5Ci的137Cs放射源,装置检测速度6 m/min、置信度95%时,设备的燃料棒长度检测精度为4 mm/1m,间隙检测精度为±0.13 mm.装置运行稳定性良好,精度满足检测需求.