Vogtle nuclear plant expansion project in Georgia reaches major milestone

A massive water tank has been lifted into place atop the Unit 4 containment vessel and shield building roof at Georgia Power’s Vogtle plant, making it so that all modules are now in place for its Vogtle 3 & 4 nuclear expansion project.

Standing 35 feet tall and weighing more than 720,000 pounds, the Passive Containment Cooling Water Storage Tank will hold approximately 750,000 gallons of water ready to flow down to help cool the reactor in the unlikely event of an emergency. The water can also be directed into the used fuel pool, while the tank itself can be refilled from water stored elsewhere on site.

The plant’s passive safety systems require no operator actions to mitigate potential emergency situations as only natural forces such as gravity, natural circulation, and compressed gas are required to achieve their safety function. No pumps, fans, diesels, chillers, or other active machinery are needed, except for a few simple valves that automatically align and actuate the passive safety systems.

The modules used for Vogtle units 3 & 4 were made in advance of arriving at the project site and put in place. Since 2011, major modules have been delivered to the site by rail and truck and included a range of plant components such as floor and wall sections and supporting structures surrounding the containment buildings and reactor vessels. The final major module arrived at the construction site in late 2019. Now, all 1,485 major modules required to complete construction had been manufactured and safely delivered.

The new Vogtle units are part of Georgia Power’s commitment to deliver clean, affordable energy and meet the goal of its parent company, the Southern Company, to have net-zero carbon emissions by 2050. Once operating, the two new units at Plant Vogtle will power more than 500,000 homes and businesses.

Also, Georgia Power announced that hot functional testing has begun for Vogtle Unit 3. This is the last series of major tests underway for the new nuclear unit ahead of the initial fuel load. The testing represents a significant step towards operations.

Hot functional testing is conducted to verify the successful operation of reactor components and systems together and confirm the reactor is ready for fuel load. As part of the testing, the site team will begin running Unit 3 plant systems without nuclear fuel and advance through the testing process towards reaching normal operating pressure and temperature.

Over the next several weeks, nuclear operators will use the heat generated by the unit’s four reactor coolant pumps to raise the temperature and pressure of plant systems to normal operating levels. Once achieved, the unit’s main turbine will be raised to normal operating speed using steam from the plant. Hot functional testing is expected to take six to eight weeks.