CEPR机组CRDM役前检查方案优化

某CEPR机组的控制棒驱动机构（CRDM）耐压壳安装完成后，发现此批次CRDM焊接见证件试验存在不合格样品。为缩短CRDM更换工期，降低对于项目整体进度的影响，在对CRDM耐压壳更换过程中通过深入研究役前检查规范，提出了一种新的役前检查策略。经实践表明，采用优化后的役前检查方案，在10 d内即完成了全部CRDM的离线役前检查，较最初的计划提前了约20 d；通过对安装后的部分CRDM进行超声和涡流检查，发现离线和在线检查结果一致，并且在线检查不存在可达性问题。 

Optimization of Pre-Service Inspection Scheme for CEPR CRDM

After the installation of the pressure housing of the control rod drive mechanism (CRDM) in CEPR units, it was found that there were unqualified samples in the certificate test of CRDM welding. In order to shorten the period for the replacement of CRDM and reduce the impact on the overall progress of the project, a new pre-service inspection strategy is put forward by studying the pre-service inspection specifications in the process of the replacement of CRDM pressure housing. The practice shows that the off-line pre-service inspection of all CRDMs is completed within 10 days by using the optimized pre-service inspection scheme, which is about 20 days ahead of the original plan; through ultrasonic and eddy current inspection of some installed CRDMs, it is found that the results of off-line and on-line inspection are consistent, and there is no accessibility problem in on-line inspections.