Vogtle Unit 4 reaches initial criticality

Georgia Power announced today that Unit 4 at the Vogtle nuclear expansion project near Waynesboro, Georgia, has safely reached initial criticality. Initial criticality is a key step during the startup testing sequence and demonstrates that -- for the first time -- operators have safely started the nuclear reaction inside the second reactor. This means atoms are being split and nuclear heat is being made, which will be used to produce steam. 

A reactor achieves criticality when the nuclear fission reaction becomes self-sustaining. Achieving initial criticality is necessary to continue the startup of the unit in order to generate sufficient heat for the production of electricity. Vogtle Unit 4 continues with startup testing, which demonstrates the integrated operation of the primary coolant system and steam supply system at design temperature and pressure with fuel inside the reactor. These tests are designed to ensure all systems are operating together and to validate operating procedures prior to declaration of commercial operation.

Now that the Unit 4 reactor has reached criticality, operators will continue to raise power to support synchronizing the generator to the electric grid and begin producing electricity. Then, operators will continue increasing power through multiple steps, ultimately raising power to 100 percent.

Vogtle Unit 3 entered commercial operation on July 31, 2023, (read more) and is providing safe, reliable, emission-free energy to Georgia today. The in-service date for Unit 4 is projected during the second quarter of 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. When operating, each of the new units can produce enough electricity to power an estimated 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.

Cautionary Note Regarding Forward-Looking Statements

Certain information contained in this release is forward-looking information based on current expectations and plans that involve risks and uncertainties. Forward-looking information includes, among other things, statements concerning the projected in-service date for Plant Vogtle Unit 4. Georgia Power cautions that there are certain factors that can cause actual results to differ materially from the forward-looking information that has been provided. The reader is cautioned not to put undue reliance on this forward-looking information, which is not a guarantee of future performance and is subject to a number of uncertainties and other factors, many of which are outside the control of Georgia Power; accordingly, there can be no assurance that such suggested results will be realized. The following factors, in addition to those discussed in Georgia Power's Annual Report on Form 10-K for the year ended December 31, 2022, and subsequent securities filings, could cause actual results to differ materially from management expectations as suggested by such forward-looking information: the ability to control costs and avoid cost and schedule overruns during the development, construction, and operation of facilities or other projects, including Plant Vogtle Unit 4, which includes components based on new technology that only within the last several years began initial operation in the global nuclear industry at this scale, due to current and/or future challenges which include, but are not limited to, changes in labor costs, availability and productivity, challenges with the management of contractors or vendors, subcontractor performance, adverse weather conditions, shortages, delays, increased costs, or inconsistent quality of equipment, materials, and labor, contractor or supplier delay, the impacts of inflation, delays due to judicial or regulatory action, nonperformance under construction, operating, or other agreements, operational readiness, including specialized operator training and required site safety programs, engineering or design problems or any remediation related thereto, design and other licensing-based compliance matters, challenges with start-up activities, including major equipment failure, or system integration, and/or operational performance, challenges related to pandemic health events, continued public and policymaker support for projects, environmental and geological conditions, delays or increased costs to interconnect facilities to transmission grids, and increased financing costs as a result of changes in interest rates or as a result of project delays; the ability to overcome or mitigate the current challenges, or challenges yet to be identified, at Plant Vogtle Unit 4, that could further impact the cost and schedule for the project; under certain specified circumstances, a decision by holders of more than 10% of the ownership interests of Plant Vogtle Unit 4 not to proceed with construction; the ability to construct facilities in accordance with the requirements of permits and licenses (including satisfaction of U.S. Nuclear Regulatory Commission requirements), to satisfy any environmental performance standards and the requirements of tax credits and other incentives, and to integrate facilities into the Southern Company system upon completion of construction; the inherent risks involved in operating and constructing nuclear generating facilities; the ability of counterparties of Georgia Power to make payments as and when due and to perform as required; the direct or indirect effect on Georgia Power's business resulting from cyber intrusion or physical attack and the threat of cyber and physical attacks; catastrophic events such as fires, earthquakes, explosions, floods, tornadoes, hurricanes and other storms, droughts, pandemic health events, political unrest, wars or other similar occurrences; and the direct or indirect effects on Georgia Power's business resulting from incidents affecting the U.S. electric grid or operation of generating or storage resources. Georgia Power expressly disclaims any obligation to update any forward-looking information.