核电厂CRDM耐压壳焊缝超声检验工艺设计

控制棒驱动机构（CRDM）耐压壳属于核电厂主回路，其连接焊缝是整个放射性回路压力边界的薄弱环节，其安全性和可靠性直接影响反应堆的安全运行状态。针对CRDM耐压壳焊缝附近空间狭小、壁厚薄、可达性差等特点，本文采用仿真技术设计了一套专用的扁平型双晶聚焦超声探头和检验工艺，试验验证结果满足规程要求，解决了核电厂在役检查的监督难点，并获得了核电厂主回路Ⅰ级部件类似焊缝检验的工艺设计和验证方法。 

Ultrasonic Inspection Process Design for CRDM Pressure Housing Weld in Nuclear Power Plant

The pressure housing of the control rod drive mechanism (CRDM) belongs to the main circuit of the nuclear power plant, and its joint weld is the weak link of the pressure boundary of the whole radioactive circuit. Its safety and reliability directly affect the safe operation state of the reactor. In view of its narrow space, thin wall thickness and poor accessibility, a special flat bicrystal focused ultrasonic probe and inspection process are designed by using simulation technology. The test results meet the requirements of the regulations. The supervision difficulties of in-service inspection of nuclear power plant are solved, and the process design and verification method of similar weld inspection of class I components of main circuit of nuclear power plant are obtained.