核电站超大环形IRWST水池内环天花后贴法施工技术

Post-paste Construction Technology of Inner Ring Ceiling of Ultra-large Annular IRWST Pool in Nuclear Power Plant

华龙一号三代核电IRWST水池内环天花分布在3个不同标高段,具有8个分区,结构复杂,且反应堆厂房内部结构施工工期紧张,综合比较先贴法、后贴法施工方案后,IRWST水池内环天花采用后贴法施工方案,分为龙骨安装和覆面安装阶段,为土建结构施工创造有利条件,且减少覆面板空间可变形自由度,保证内环天花覆面板最终成型质量,解决不锈钢薄板焊接变形大等难题,控制天花埋件、套管、罩壳、覆面板的安装定位精度。同时水池内部仅对天花覆面板进行焊接,不影响楼板上部结构施工,缩短施工场地被占用周期。

In view of the complex structural form of the inner ring ceiling of the IRWST pool of the third-generation nuclear power plant of Hualong No.1, which is distributed in three different elevation sections and eight partitions, and the tight construction period of the internal structure of the reactor building, after comprehensively comparing the construction schemes of the prior paste method and the post-paste method, the inner ring ceiling of the IRWST pool adopts the post-paste construction scheme, which is divided into the stages of keel installation and sheathing installation. It creates favorable conditions for the construction of civil engineering structures, reduces the degree of deformation of the sheathing panel space, ensures the final forming quality of the inner ring ceiling sheathing panel, solves the problems such as large welding deformation of stainless-steel thin plates, and controls the installation and positioning accuracy of ceiling buried parts, casing pipe, encloser and surface panel. Meanwhile, the occupation period of the construction site can be shortened because only the ceiling panel is welded inside the pool, which does not affect the construction of the superstructure of the floor.