Vogtle Unit 4 begins Hot Functional Testing

Staff Report

Tuesday, March 21st, 2023

Georgia Power today announced that hot functional testing has begun for Vogtle Unit 4. Hot functional testing marks the last series of major tests underway for the new nuclear unit ahead of initial fuel load. The testing represents a significant step towards operations and providing customers with a reliable, carbon-free energy source for the next 60 to 80 years.

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 4 plant systems, without nuclear fuel in the reactor, and advance through the testing process towards reaching normal operating pressure and temperature.

As part of the testing process, 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 normal operating temperature and pressure levels are achieved and sustained, the unit’s main turbine will be raised to normal operating speed using steam from the plant. During these series of tests, nuclear operators will be able to exercise and validate procedures as required ahead of fuel load.

Vogtle Unit 4 is projected to enter service in late fourth quarter 2023 or first quarter 2024.


The new Vogtle units are an essential part of Georgia Power's commitment to delivering clean, safe, reliable and affordable energy to its 2.7 million customers. Once operating, the two new units, which will be clean energy sources that produce zero air pollution, are expected to power more than 500,000 homes and businesses. Southern Nuclear will operate the new units on behalf of the co-owners: Georgia Power, Oglethorpe Power, MEAG Power and Dalton Utilities.