Zhangzhou Nuclear Power Unit 4 Completes Hoisting of Four Internal Structure Modules

From August 18 to 27, CNNC 24 completed the hoisting of four concrete modules for the internal structure of Zhangzhou Nuclear Power Unit 4 within 10 consecutive days, covering the evaporator compartments of Loops 3, 2, and 1 as well as the pressurizer compartment, creating conditions for subsequent loop installation and commissioning work.

The evaporator and pressurizer are key equipment in the nuclear island loops. Their corresponding compartment concrete modules serve both load-bearing fixation and protection functions, representing an important embodiment of the "Hualong One" defense-in-depth safety philosophy at the civil construction stage. The four modules hoisted this time are all irregularly shaped structures, all adopting the "off-site prefabrication + integral modular hoisting" process, with a total hoisting weight of approximately 2,400 tons.

Compared with Unit 3, Unit 4, on the basis of achieving modular construction of the three loop evaporator compartments, has for the first time changed the pressurizer compartment from the method of rebar cage hoisting with internal concrete pouring to integral hoisting of off-site prefabricated concrete modules. This change imposes higher requirements on construction organization, process control, safety and quality management, and on-site overall coordination.

To ensure the safe implementation of the continuous hoisting operations, the project team conducted full-process risk identification for hoisting, organized trial hoisting drills, and continuously optimized the special construction plan. During the hoisting period, safety management personnel were stationed at key points to exercise full-process control over the operations. In response to frequent heavy rainfall during the preparation phase, typhoon and flood prevention measures were implemented simultaneously on site to ensure the orderly progress of hoisting preparation and execution.

During construction, the project team also applied integrated sleeve tooling to resolve the matching issue between prefabrication yard positioning and internal structure dowel bar positions, replacing the traditional method of manual individual measurement and verification, thereby reducing manpower input while improving module positioning efficiency. The successful hoisting of these four modules marks phased progress in the civil modular construction of Zhangzhou Nuclear Power Unit 4.