某核电站热试期间堆芯上栅格板嵌入件腐蚀原因分析

Analysis of Corrosion Causes of Grid Plate Inserts on the Core During Thermal Test in a Nuclear Power Plant

某核电站的堆芯上隔栅板嵌入件表面堆焊钴基合金,在热试后的检查中发现其表面发生了腐蚀。本文采用显微观察、成分测试、金相试验、硬度检验、SEM和能谱分析的方法对嵌入件及腐蚀产物进行检查,检查结果表明:嵌入件的化学成分、金相结构、硬度均符合规范要求,SEM检查结果正常,但在腐蚀产物的能谱分析检查中发现有氯元素的存在,通过对安装现场及运行工况分析,认为该腐蚀是反应堆热试阶段在多个因素相互作用下发生的特殊行为。

In a nuclear power plant, the surface of the grid plate insert on the core of a nuclear power plant was welded with cobalt-based alloy. After the thermal test, it was found that a certain surface was corroded. This article uses microscopic observation, composition test, metallographic test, hardness inspection, SEM and energy spectrum analysis methods to inspect the embedded parts and corrosion products. The inspection results show that the chemical composition, metallographic structure and hardness of the embedded parts meet the specifications. The SEM inspection results are normal, but the presence of chlorine is found in the energy spectrum analysis inspection of the corrosion products. Through the analysis of the installation site and operating conditions, it is believed that the corrosion is a special phenomenon that occurs under the interaction of various factors during the thermal test stage of the reactor. behavior.