The containment vessel bottom head has been installed for unit 3 at the Vogtle plant in Georgia. It involved the heaviest lifting operation performed so far at the construction site.
|The containment vessel bottom head is lowered onto its cradle (Image: Georgia Power)
The component - measuring almost 40 metres wide, 12 metres tall and weighing over 900 tonnes - was assembled on-site from pre-fabricated steel plates. The cradle for the containment vessel was put in place on the unit's nuclear island in April. The completed bottom head was raised by a heavy lift derrick and placed on the cradle on 1 June, Georgia Power announced.
Site preparation for two new reactors at Vogtle began in mid-2009, with a licence to build and operate them following in February 2012. But project leader Georgia Power encountered problems that forced it to amend its licence and use a different concrete mix. This licensing issue was resolved at the end of February but the delay pushed back start-up dates for the two new units to late 2017 and late 2018.
However, the modular design of the AP1000 and the scope of the project to build two units simultaneously have enabled Georgia Power and its primary contractors Westinghouse and CB&I (which purchased Shaw in July 2012) to continue making progress during the delay. The first ring of the containment is already complete, the second is almost finished, and work has started on the final third ring.
Other large components including the reactor pressure vessel, pressurizer and condenser are already on site and the piping to connect them has been manufactured and is ready for shipping. The turbine building's lower foundation is also complete and the unit's single cooling tower is over 40% complete.
Researched and written
by World Nuclear News