Milestones for Vogtle construction

09 October 2017

The Vogtle AP1000 construction project in Georgia has marked multiple construction milestones including a concrete "super placement" for unit 3 and the lift of the 237-tonne CA03 module for unit 4.

The concrete "super placement" at Vogtle 3 took 71 hours to complete (Image: Georgia Power)

The placement of 1844 cubic yards (1410 cubic metres) of concrete in four key areas of unit 3's containment vessel required a continuous operation lasting 71 hours. Concrete was placed in the unit's refuelling cavity, the bottom of the in-containment refuelling water storage tank, the west steam generator cubicle walls and the pressuriser cubicle walls.

The CA03 module placed in unit 4 is part of the unit's 75,300 cubic feet (2132 cubic metre) in-containment water storage tank, which will be filled with borated water to provide a passive heatsink for the operating reactor and backup cooling for the reactor vessel. The CA03 is one of the structural steel modules known as super modules because they are too large to transport and require on-site assembly.

As well as the concrete placement and the CA03 module, the past month has seen placement of the 35-tonne CA33 floor module at unit 3 and placement of unit 4's deaerator inside the turbine building. The deaerator, which is 148 feet (45 metres) long and weighs 300 tonnes, will remove dissolved gases, such as carbon dioxide and oxygen, from feedwater, preventing corrosion and helping to reduce plant maintenance and operating costs.

Georgia Power owns 45.7% of the project to construct two AP1000 units at the Vogtle site, near Waynesboro, with co-owners Oglethorpe Power (30%), MEAG Power (22.7%) and Dalton Utilities (1.6%). Following constructor Westinghouse's Chapter 11 bankruptcy filing earlier this year, Georgia Power in August filed a recommendation with the Georgia Public Service Commission to complete construction of the two AP1000 units as the most economic choice for customers. The commission is expected to review the recommendation and make a decision on the future of the project as part of its 17th Vogtle Construction Monitoring proceeding.

Project management and control at the site transitioned to Southern Nuclear after a services agreement between Westinghouse and Vogtle's co-owners became effective on 27 July and, in August, Georgia Power contracted with Bechtel to manage daily construction efforts under the direction of Southern Nuclear. US Energy Sercretary Rick Perry announced on 29 September  further support of up to $3.7 billion in loan guarantees to the owners of the Vogtle project, to which the Department of Energy has already guaranteed $8.3 billion in loans.

Vogtle unit 3 is expected to start commercial operation in November 2021 and unit 4 in November 2022.

Researched and written
by World Nuclear News