Alvin W Vogtle nuclear power plant is being expanded with two new Westinghouse Advanced Passive (AP1000) reactors. Credit: Georgia Power Company.
The Vogtle expansion project is expected to provide electricity to approximately 500,000 homes and businesses. Credit: Georgia Power Company.
Unit three of the expansion project is expected to be operational in 2021. Credit: Georgia Power Company.

Alvin W Vogtle nuclear power plant (NPP) located in Waynesboro, Georgia, US, is undergoing an expansion, which will add two new units designated three and four, each with a capacity of 1,117MW.

The two new units will be the first advanced Generation III+ reactors to be installed in the US and also the first new nuclear units to be built in 30 years in the country. Unit three is expected to be commissioned in November 2021, followed by unit four in November 2022.

The project is being carried out by Georgia Power and Southern Nuclear, both subsidiaries of Southern Company. Southern Nuclear is also the operator of the plant.

The NPP is jointly owned by Georgia Power (45.7%), Oglethorpe Power Corporation (30%), Municipal Electric Authority of Georgia (22.7%), and Dalton Utilities (1.6%).

The expansion project will meet the rising demand for electricity in the state of Georgia by 2030 and produce sufficient electricity to power 500,000 homes and businesses in the state.

The new units will produce carbon-free energy, which is equivalent to removing more than one million cars a year from the road.

Vogtle NPP expansion project details

The expansion project was approved by the Georgia Public Service Commission (PSC) in March 2009, followed by the award of construction and operating licenses (COLs) by the Nuclear Regulatory Commission in February 2012.

It will add two Westinghouse Advanced Passive (AP1000) pressurised water reactors with a capacity of 1,117MW each. The AP1000 reactor is designed on a simple concept and includes safety features such as auto shut down.

“The expansion project will meet the rising demand for electricity in the state of Georgia by 2030 and produce sufficient electricity to power 500,000 homes and businesses.”

The reactor uses gravitational force, condensation and natural circulation to prevent overheating of the core. It is easy to operate, highly reliable, and reduces maintenance costs.

The AP1000 also features built-in and online testing services for critical components.

Construction on Vogtle NPP expansion

Major components for the NPP, including the first components of the unit three reactor vessel, started arriving at the site in late-2012.

Two 1.4 million-pound steam generators for unit three have been installed and the 35t CA33 floor module was placed inside the containment vessel of the unit, as of January 2018. The CA33 floor module was delivered in three sub-modules and welded on site.

A 60ft-high pressure compartment for unit four was also installed along with the placement of the 148ft, 300t de-aerator inside the turbine building of the unit.

The de-aerator functions similarly to a water purifier, eliminating dissolved gases such as carbon dioxide and oxygen from feed water. It also helps in preventing corrosion and indirectly reduces plant maintenance and operating costs.

Two of the four accumulator tanks of the AP1000 passive core cooling system, and new shield building panels for both units were also installed.

The 237t CA03 module for unit four was installed in October 2017 and included the placement of 1,844 cubic yards of concrete. The CA03 module is a critical component of the In-Containment Refueling Water Storage Tank (IRWST), which provides heatsink within containment and acts as backup cooling for the reactor vessel.

The final containment vessel ring for Vogtle Unit-3 was placed in December 2018, and the unit was declared test-ready in May 2019. Georgia Power ordered the first nuclear fuel load for Vogtle Unit-3 in July 2019, while middle containment vessel ring for Vogtle Unit 4 was placed in the same month.

Construction works related to turbine islands, cooling towers and nuclear islands are in progress.

Financing for Vogtle NPP expansion project

The US Department of Energy (DOE) provided $265m in loan guarantees for the project. It also provided a conditional commitment of an additional $1.67bn in loan guarantees in September 2017, which was approved in March 2019.

Contractors involved

Westinghouse (previously a subsidiary of Toshiba) was awarded the construction contract for the project. The company, however, went bankrupt during the course of construction and was replaced by Bechtel.