The largest module has been installed at unit 4 of the US Vogtle nuclear construction project in Georgia. Southern Company subsidiary Georgia Power said the CA20 module and sub-modules were assembled from prefabricated wall and floor sections within the modular assembly building at the Vogtle site. The completed CA20 module was installed within Vogtle 4's nuclear island on 20 August. During the three-hour operation, the world's largest crawler crane was used to hoist the 840t module into position.
The CA20 module comprises plant and equipment for used fuel storage, transmission, the heat exchanger and waste collection, among other things. It is the largest component to be used in the construction of AP1000 units. Some 1376 cubic metres of concrete will now be poured to fill the walls of the CA20 module. Unit 4 is one of two Westinghouse AP1000 reactors under construction at Vogtle, where two pressurized water reactors are already operating. Unit 3's CA20 module was lifted into place in March 2014. Unit 3 is expected to begin operation by the middle of 2019, and Vogtle 4 in mid-2020.