A team led by Bechtel has completed installation of a 745-ton reactor dome at the 2.43GW Vogtle nuclear power plant in Georgia, US as part of a $28bn expansion project.

Bechtel Vogtle dome

Image: Reactor dome being lifted onto Unit 3 at Vogtle nuclear power plant. Photo: courtesy of Bechtel.

The expansion project at the Vogtle nuclear power plant will see addition of Units 3 and Units 4 near Waynesboro, with each of them to have a capacity of around 1,117MW.

The Bechtel-led team installed a huge dome, measuring 130ft in diameter, on a new nuclear reactor building at Units 3 and 4. Known as the “top head”, the dome is the roof of the steel structure that houses the nuclear reactor of Unit 3.

In 2017, Bechtel was given a contract for completing construction of Vogtle Units 3 and 4 under the management of Southern Nuclear, which is the operator of the existing two units of the Vogtle nuclear power plant.

Prior to the mounting of the dome, installation of the nuclear steam supply system of Unit 3 was completed.

The nuclear steam supply system comprises reactors, steam generators, reactor coolant pumps, pressurizer and associated piping. According to Bechtel, the installed equipment are essential in helping the nuclear power system produce the steam required to power the unit’s turbine generator to generate electricity.

In January, Bechtel completed installation of the 225,000-pound pressurizer inside the reactor building of Unit 4. The pressurizer’s role is to deliver pressure control inside the reactor coolant system during the operation of the unit.

Bechtel project director Brian Reilly said: “I am proud of our team for completing these milestones safely and demonstrating our drive to deliver these units as promised for our customer and this community.

“We stand firmly behind Vogtle 3 and 4 as a safe, reliable solution for carbon-free electricity for Georgia homes and businesses, and we are proud to be a part of building the future of nuclear power in the United States.”

Unit 3 of the Vogtle nuclear power plant is slated to be commissioned in 2021, while Unit 4 is targeted to be brought into service in the following year.

The Vogtle nuclear power plant is co-owned by Georgia Power, Municipal Electric Authority of Georgia (MEAG), Dalton Utilities and Oglethorpe Power, who all reached an agreement to move ahead with the expansion project in September 2018.

In another development, Georgia Power and the US Department of Energy (DOE) have finalized $1.67bn loan guarantee for the construction of the new Vogtle units.

Georgia Power chairman, president and CEO Paul Bowers said: “We have made significant progress since taking over construction at the site and expect that momentum to continue this year.

“Placement of the Unit 3 top head is a historic milestone for the project, reflecting the hard work and dedication of the Vogtle 3 & 4 team as we transition these units closer to operation.”