Vogtle 4 (Image: Georgia Power)

The process of loading the 157 fuel assemblies into the core of the second AP1000 reactor at the site is pivotal for the reactor, which has a projected in-service date of late this year or early in 2024.

Fuel loading began after Southern Nuclear's receipt in July of a 103(g) finding from the US Nuclear Regulatory Commission, confirming that all the standards identified in the combined construction and operation licence have been met and that the plant has been built and will operate in conformity with its licence.

The new fuel assemblies - each one containing 264 fuel rods - are now being transferred, one at a time, from the reactor's used fuel pool into its core. The Westinghouse-designed reactor's fuel has been manufactured at the Columbia Fuel Fabrication Facility in South Carolina.

Once fuel loading is complete, startup testing will demonstrate the integrated operation of the primary coolant system and steam supply system at design temperature and pressure with fuel inside the reactor. Operators will bring the plant from cold shutdown to initial criticality, synchronise the unit to the electric grid and systematically raise power to 100%.

Vogtle 4 is following in the footsteps of Vogtle 3, which was declared in commercial operation at the end of July. It will be the sixth AP1000 reactor to reach commercial operation globally: two AP1000s are in commercial operation at each of the Sanmen and Haiyang nuclear power plants in China.

Southern Nuclear and Georgia Power, both subsidiaries of Southern Company, took over management of the construction project in 2017 following Westinghouse's Chapter 11 bankruptcy. The units are co-owned by Georgia Power, Oglethorpe Power, MEAG Power and Dalton Utilities, and will be operated by Southern Nuclear.

"On the heels of unit 3 reaching commercial operation, today's good news of fuel load at unit 4 continues the site's positive momentum and marks another significant milestone at the Vogtle construction project, which represents the first advanced commercial nuclear project in the US in more than three decades," Oglethorpe Power President & CEO Mike Smith said.