8月7日17时32分，历经19个小时的连续奋战后，三门核电3号机组常规岛跨栏跑的第一跨：10.7米层楼板浇筑作业顺利完成，混凝土总浇筑量351.5立方米。10.7米层结构是整个第一跨土建结构中施工难度最大、结构最为复杂的层段，它的浇筑不仅为220千伏倒送电跨岛电缆通道的贯通创造了条件，也为后续主泵变频器房间的形成奠定了坚实的基础。

第一跨10.7米层墙体上预埋了两组直径1905毫米、总重约8吨的主蒸汽管道贯穿件套筒，该套筒周围设有非常密集的环向筋及箍筋，重量达到14吨。项目团队积极践行CAP1000机组“应模尽模”的理念，在地面上将贯穿件套筒与周围钢筋提前进行了绑扎与固定，随后采用履带吊对该土建模块进行整体吊装，不仅提高了密集钢筋的施工质量、节省了施工时间，还降低了现场狭窄作业面下钢筋绑扎的安全风险。

第一跨土建结构改抗震I类是三门核电二期工程的重大变更之一，作为核岛和常规岛相互关联的纽带，第一跨施工对推进项目整体进度尤为重要。三门核电项目指挥中心始终秉承“六个一”理念，坚持“安全第一，质量第一”的原则，充分发挥党建引领及业主主导作用，自第一跨开工以来，三门核电与各参建团队协同并进、攻坚克难，多次组织专题会优化设计和施工方案，在高质量完成第一跨结构重新设计的同时，努力攻克了第一跨区域作业面狭长、操作空间受限、物料运输不便、埋件安装精度高、钢筋密集等各类施工难题。

At 17:32 on August 7, after 19 hours of continuous fighting, the first span of the regular island hurdle run of Sanmen Nuclear Power Unit 3:10.7 meters of floor slab pouring operation was successfully completed, and the total concrete pouring volume was 351.5 cubic meters. The 10.7 meter layer structure is the most difficult and complex layer in the whole first span civil structure. Its pouring not only creates the conditions for the transmission of 220 kV inverted power across the island cable channel, but also lays a solid foundation for the formation of the subsequent main pump frequency converter room.

The first 10.7 meter wall is embedded with two sets of main steam pipe penetration sleeves with a diameter of 1905 mm and a total weight of about 8 tons. The sleeves are surrounded by very dense circumferential reinforcement and stirrup, weighing up to 14 tons. The project team actively implemented the concept of "mold to mold" of CAP1000 unit, bundled and fixed the perforating sleeve and surrounding steel bars on the ground in advance, and then used a crawler crane to lift the civil construction module as a whole, which not only improved the construction quality of dense steel bars, saved construction time, but also reduced the safety risk of steel bars lashing under the narrow working surface on the site.

Seismic Class I of the first span civil structure reform is one of the major changes in the second phase of Sanmen Nuclear Power project. As the link between nuclear island and conventional island, the construction of the first span is particularly important to promote the overall progress of the project. Sanmen Nuclear power project command center has always been adhering to the "six one" concept, adhere to the principle of "safety first, quality first", give full play to the leading role of party construction and owners, since the start of the first span, Sanmen nuclear Power and the construction teams to work together, overcome difficulties, many times to organize a special meeting to optimize the design and construction plan, in the high quality of the first span structure redesign at the same time, Efforts have been made to overcome various construction problems such as narrow and long operation surface, limited operating space, inconvenient material transportation, high installation accuracy of embedded parts, and dense reinforcement.