主管道是核电站关键设备之一，在基于法国RCCM规范的主管道焊缝射线检测过程中，常会出现射线检测底片质量不合格、验收标准理解错误、缺陷无法准确定性等问题，给主管道焊缝质量带来较大风险。通过对标准的解读，分析射线检测各种透照方法的优缺点，优化了主管道射线检测透照方法；并充分利用图示和实例信息深入剖析规范，以达到正确理解RCCM规范，准确评定缺陷的目的。

The main pipeline is one of the key equipment in a nuclear power plant. With a relatively large thickness, the main pipeline is checked and accepted according to the RCCM, a French standard. Therefore, problems such as disqualification of the negative film during radiographic examination, misunderstanding of the check and acceptance standard, confirmation of the defect and the like often happen. And, these problems might threaten the welding quality of the main pipeline. This article elaborates the RCCM, analyzes the advantages and disadvantages of various radiographic examination methods and tries to optimize the main pipeline radiographic examination method. It also aims to facilitate the correct understanding of RCCM and helps to make a correct evaluation of the defect through graphic representations and examples.