3月18日18时05分，中核五公司承建的三澳核电1号机组下部堆内构件一次插堆圆满成功，标志着三澳核电项目1号机组堆内构件正式转入安装阶段，为保障机组冷试奠定了坚实基础。

下部堆内构件是核岛重要的主设备之一，为燃料组件在反应堆压力容器内提供支撑和定位。在下部堆内构件首次被插入压力容器时，对其定位精度的要求极高。在此过程中，筒体管嘴与压力容器管嘴之间的间隙极为狭小，这一微小的距离肉眼难以察觉。为确保下部堆内构件能够顺利且精确地插入压力容器，需进行精确的对中调整，吊装的操作难度极大。

安全是核工业的生命线，中核五公司坚持“零事故”的安全管理目标和“全员参与”的安全管理原则，抓实开展各项安全生产工作。在中核五公司三澳项目部的共同努力下，严格落实项目安全管理要求，确保了下部堆内构件首次插堆现场施工的安全可控。在质量管理方面，中核五公司三澳项目部高度重视异物防治和成品保护工作，建立成品保护防异物管理体系，确保下部堆内构件一次插堆过程中现场防异物工作无遗漏、无死角。在创新技术方面，中核五公司结合堆内构件插堆施工进行一系列发明和工装创新。施工前技术团队针对下部堆内构件一次插堆组织各方人员进行模拟推演。编制专项施工方案，从多个角度进行风险预判，识别现场吊装可能的突发因素，制定切实可行的解决措施，极大提升了施工效率和施工安全。

At 18:05 on March 18, the lower reactor internals of Sanao Nuclear Power Unit 1 built by CNNC 5 were successfully inserted into the reactor, marking the official transfer of the reactor internals of Sanao Nuclear Power Project Unit 1 to the installation stage, laying a solid foundation for ensuring the cold test of the unit.

The lower reactor internals are one of the important main equipment of the nuclear island, providing support and positioning for the fuel assemblies in the reactor pressure vessel. When the lower reactor internals are inserted into the pressure vessel for the first time, the positioning accuracy is very high. In this process, the gap between the nozzle of the cylinder and the nozzle of the pressure vessel is extremely narrow, and this tiny distance is difficult to be detected by the naked eye. In order to ensure that the inner components of the lower reactor can be smoothly and accurately inserted into the pressure vessel, accurate alignment adjustment is needed, and the operation of hoisting is extremely difficult.

Safety is the lifeline of the nuclear industry. CNNC 5 adheres to the safety management goal of "zero accident" and the safety management principle of "full participation", and earnestly carries out various safety work. Under the joint efforts of the Sanao Project Department of CNNC No. 5, the project safety management requirements were strictly implemented to ensure the safety and controllability of the site construction of the lower reactor internals for the first time. In terms of quality management, the Sanao Project Department of CNNC No. 5 attaches great importance to the prevention and control of foreign bodies and the protection of finished products, establishes a management system for the protection and prevention of foreign bodies of finished products, and ensures that there are no omissions and dead corners in the on-site prevention of foreign bodies during the one-time insertion of the inner components of the lower pile. In terms of innovative technology, CNN5 has carried out a series of inventions and tooling innovations in combination with the construction of reactor internals. Before construction, the technical team organized all parties to conduct simulation and calculation for the lower reactor internals. The preparation of special construction plans, risk prediction from multiple angles, identification of possible unexpected factors of on-site lifting, and formulation of practical solutions greatly improve the construction efficiency and construction safety.