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Modularization and Construction
The AP1000™is designed to incorporate modern, modular construction techniques. This allows construction tasks that were traditionally performed in sequence to now be completed in parallel. Factory-built modules can be assembled at the site in a planned construction schedule of 36 months from first concrete pour to fuel load. This duration has been verified by experienced construction managers through 4D (3D models plus time) reviews of the computer-simulated construction sequence.
The benefit of structural, piping and equipment modules is that they provide:
- Shortened construction schedule
- Reduced field manpower
- Increased factory-based manufacturing and assembly of modules
- Improved quality (pre-testing and inspection of modules prior to shipment)
- Reduced site congestion
Points of interest as detailed in the above animation:
Day 1 Basemat goes in as one continuous pour over two days. Drain pipes and sump pump modules that will be embedded in the basemat have already been placed.
Day 4 A large concave rebar is placed in the containment area, and two pump stands are placed.
Days 7 and 8 First weekend shown; no activity. (Weekends used for contingency)
Day 11 Large rebar assembly (already pre-wired) goes in as one lift, along with some pipes, walkways, etc. Diameter is 145 feet. This is the largest lift, although not the heaviest.
As days go by, non-adjacent walls are poured.
Day 24 Lower head of containment vessel installed. While viewing the construction with this tool, one MONTH of schedule is saved by installing the pedestal for the lower head of containment vessel with the initial rebar lift on day 11. That allowed this particular activity to be moved up, thus reducing the critical path.
Day 27 Large structural module CA20 is going in (multi-day event). This is approximately four stories high and weighs about 700 metric tons. Several crane companies were contacted about this lift. All of the companies have previously lifted more than this and agreed that this lift would be within their parameters. The module is constructed of steel plates and other structural components, and will be filled with concrete later not for strength, but as containment. Entire rooms are already constructed, piped, wired, and even painted within this module, thus eliminating LARGE amounts of on-site labor and time.
Week 6 Battery racks (red) are beginning to go in, empty. Structural module CA04, the reactor vessel cavity and reactor coolant drain tank room, begins to be placed.
Week 8 All exterior concrete walls to grade are in, all battery racks are in, and concrete is being poured around the reactor vessel cavity. More structural models are in, and the walls of CA20 are beginning to be filled with concrete not for structure, but for shielding.
Week 9 Structural module CA01, which forms the refueling canal, steam generator compartments, and the pressurizer compartment, is placed in containment. Slightly more than two months since the pouring of the basemat, another large module has been placed (CA01). CA20 walls have been completely filled with concrete.
Week 10 First steel ring of containment, 130 feet in diameter, goes in. Some ceiling/floor modules on the clean side have been placed over the battery rack rooms. Some piping modules are being placed.
Week 12 Modules KB11 and KB12 have been fully installed. (The demineralizers and filters are shown as aqua-colored tanks along front wall of plant). The next level of rooms above the battery racks has been capped with concrete floor modules.
Week 16 Various HVAC and raceways installed on the clean side (yellow and green).
Week 24 Spargers installed in containment.
Week 27 Ceiling of chemical and volume control system (CVS) compartment is installed in containment.
Week 31 Second ring of containment installed (goes back to in process for a few weeks because various actions are being taken on it and the modules that are considered part of it).
Week 59 Pressurizer installed (blue inside containment).
Week 65 Both dirty and clean auxiliary buildings are under roof.
Week 69 A steam generator is installed (larger blue item in containment).
Week 71 Polar crane is installed.
Week 88 Upper head of containment is installed.
Week 91 Upper segment of air baffle system is installed above upper head of containment.
Week 101 Shield building roof is constructed.
Week 109 Outer wall of passive containment cooling (PCC) water storage tank is constructed on top of containment.
Week 111 Inner wall of PCC water storage tank is constructed on top of containment.
Week 114 Roof of PCC tank is constructed.
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