Vogtle Electric Generating Plant

Alvin W. Vogtle Electric Generating Plant
Company type	Nuclear power facility
Industry	Electric power generation
Headquarters	Burke County, near Waynesboro, United States
Area served	United States
Products	Electricity

The Alvin W. Vogtle Electric Generating Plant, commonly known as Plant Vogtle, is a nuclear power facility consisting of four reactors located in Burke County, near Waynesboro, Georgia. As of 2025, it holds the distinction of being the largest nuclear power station in the United States, with a total generating capacity of 4,536 megawatts, and it is the sole U.S. site operating four reactors simultaneously. The plant is named in honor of Alvin Vogtle, who served as chairman of both Alabama Power and Southern Company boards.

Units 1 and 2 utilize Westinghouse pressurized water reactors (PWRs) coupled with General Electric steam turbines and generators. These two units were completed in 1987 and 1989, respectively, delivering a combined gross output of 2,430 megawatts. The facility employs two large natural-draft cooling towers, each standing tall to facilitate main condenser cooling processes. Additionally, four smaller mechanical draft towers provide nuclear service cooling water (NSCW) essential for safety systems, auxiliary functions, and decay heat removal when the reactors are offline. Each reactor unit is supported by one natural-draft and two NSCW towers. The Nuclear Regulatory Commission extended the operating licenses for Units 1 and 2 in 2009, allowing them to function through 2047 and 2049 accordingly. Initial construction costs for these reactors escalated significantly from an estimated $660 million to $8.87 billion based on 1989 dollar values.

The development of Units 3 and 4 commenced in 2009 featuring Westinghouse AP1000 reactor designs alongside nearly equally tall natural-draft cooling towers. These newer units encountered substantial delays and budget increases, with certified cost estimates initially set at $14 billion by 2017. Factors contributing to these overruns included contractor-related setbacks and the bankruptcy filing by Westinghouse in 2017. By 2018, projected expenses had climbed to approximately $25 billion, then rose above $28.5 billion by 2021, ultimately reaching $34 billion by 2023 while Unit 4 remained under construction.

Commercial operation for Unit 3 began on July 31, 2023, representing the first startup of a new U.S. nuclear reactor in seven years. Unit 4 followed suit with its commercial launch on April 29, 2024.

Regarding financials through the third quarter of fiscal year 2024, Georgia Power reported net capital expenditures for Units 3 and 4 totaling $10.65 billion, plus an additional $83 million related to site demobilization activities. This figure includes $1.2 billion borne solely by Georgia Power without partner participation and about $1.9 billion recouped from settlements with Toshiba and customer refunds. Given Georgia Power’s ownership share of 45.7%, the total capitalized construction costs attributed to Units 3 and 4 amount to roughly $23.76 billion. Financing charges of $3.53 billion were recovered via ratepayer surcharges prior to project completion.

Units 1 and 2

The design of Vogtle’s Units 1 and 2 incorporates identical Westinghouse four-loop reactor systems. Each reactor is housed within a containment structure composed of a steel-lined concrete cylinder that is prestressed and post-tensioned, capped by a hemispherical dome. This containment configuration was engineered by the Los Angeles Regional Office of Bechtel Corporation.

Power Uprate

In 2008, Vogtle units 1 and 2 experienced a power boost of 1.7% through an "Appendix K" uprate, commonly referred to as a Measurement Uncertainty Recapture (MUR) uprate. These uprates, which remain below 2%, increase reactor output by utilizing enhanced feedwater flow measurement methods, particularly ultrasonic flowmeters, which provide greater precision in determining reactor power. This improved accuracy decreases uncertainty margins, enabling operation nearer to the design capacity while upholding safety standards.

Following a thorough safety assessment verifying the facility's ability to manage the heightened power level, the NRC granted approval for Southern Nuclear’s License Amendment Request in March 2008. Unit 1 received its uprate during the Spring 2008 refueling shutdown, with Unit 2 following suit during the Fall outage.

Electricity production

**Annual and Monthly Electricity Generation (**MWh) at Vogtle Electric Generating Plant
Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Total Annual Generation
2001	1,771,298	1,595,018	1,741,308	1,016,060	1,589,508	1,677,918	1,728,650	1,590,577	1,668,988	1,756,972	1,700,826	1,763,938	19,601,061
2002	1,766,985	1,595,144	1,003,394	1,063,031	1,748,812	1,680,300	1,727,932	1,723,792	1,668,444	993,370	851,998	1,234,136	17,057,338
2003	1,756,418	1,597,739	1,594,304	1,699,505	1,659,413	1,679,656	1,727,929	1,431,140	1,477,732	1,078,977	1,673,705	1,770,700	19,147,218
2004	1,758,609	1,605,957	1,628,483	1,314,845	1,224,113	1,669,584	1,717,020	1,646,446	1,674,477	1.744.280	1588754	1758389	19.330.957
2005	1688533	1588104	1195063	1369839	14812221	1380875	1713562	1715446	1298644	1225946	1692494	1463302	17.813.029
2006	1753949	1186635	1422733	1403832	1733444	1654782	1715255	1574770	1226224	867031	1672989	1735509	17.947.153
2007	1736443	1557456	923930	813673	1577666	1636196	1685127	1674106	1606215	1703033	1665714	1717334	18.296.893
2008	17225551	1607474	1242777	950508	1725749	1652026	1704667	1704456	1159653	1040027	1501696	1765969	17.777.553
2009	1772030	1599207	1739139	1701696	1743997	1672730	1730046	1727776	1325345	1067476	1681867	1524615	19.285.924
2010	1771935	1601769	1044133 1466689 174084 1668687 1721356 1719760 1678059 1736954 1697292 1763002	19.610.477
2011 1772047 1577982 998399 1471153 1743916 1670138 1719965 1696948 122783 1378417 1706924 1765579	18.729.299
2012 1767029 1650456 1751254 162196 173831 1678238 1716979 1723812 123867 1200884 1708873 1761729	19.558.197
2013 1759700 1521749 1064929 1593994 1742955 1444462 1719712 1722736 1674648 1405239 1671106 1757723	19.078.953
2014 1766152 1573760 1289366 1045619 173427 1664928 1559250 1572578 1123013 1260339 1707757 1763157	18.060.190
2015 1767479 1597689 1639709 169075 1699520 166646 171561 1720074 1358956 1029560 1701017 1754382	19.341.208
2016 1770487 1651326 1073319 169864 1686965 1658443 1715368 171845 1673737 1744574 1705910 1763008	19.860.229
2017 1760272 1463126 1181658 1560675 173683 1636063 1726003 1726126 1272373 1634109 1708479 1772149	19.177.863
2018 1778425 1595567 1769826 1708980 1746083 1677112 1666049 1728966 1251325 1545491 1716325 1774977	19.959.126
2019 1776734 1596282 1113145 1624150 1742464 1660324 1579918 1720092 1671583 1743399 1717369 1728840	19.674.300
2020 1769498 1649399 106498 167678 174979 158666 172203 1274347 1350907 174998 150022 1763198	18.857.818
2021 1771536 1599483 1758828 1682038 1748480 1677184 1726530 1691270 1140978 152866 171608 1745838	19.786.908
2022 1766154 1581724 1005105 148889 163497 168052 169042 173454 168891 176378 170872 177142	19.515.206
2023 1773225 1589357 986828 1864548 2075533 1969453 185272 2402000 1839998 254746 245267 241937	23.500.183
2024 2440742 2396014 280822 279642 334711 304561 306616 333560 220299 273284 246477 323529	33.871.811

Power outage event

On March 20, 1990, the plant experienced a power outage when a truck in the 230 kV switchyard collided with a support column for the feeder line that supplied electricity to Unit 1-A's reserve auxiliary transformer (RAT). At that moment, RAT 1-B was offline undergoing maintenance, leaving RAT 1-A responsible for powering both emergency electrical trains. The non-emergency trains received power through back-feed from the main step-up transformer to the unit auxiliary transformers (UAT). Additionally, emergency diesel generator (EDG) 1-B was also out of service for maintenance.

In the aftermath, EDG 1-A failed to initiate due to a safety trip, resulting in loss of power to critical circuits and causing the shutdown of the residual heat removal (RHR) pump cooling Unit 1’s core, which was nearing completion of a refueling outage. This failure prevented activation of backup RHR systems and posed a risk of core temperature increase despite Unit 1 being offline. Although non-safety power sources remained operational, they were unable to supply essential trains because of system design constraints.

At 9:40 a.m., operators declared a site area emergency (SAE) after vital power was lost for over fifteen minutes. After several unsuccessful attempts, an emergency startup procedure bypassing EDG safety mechanisms successfully started EDG 1-A at 9:56 a.m. This restored power and allowed operation of RHR-A, leading to the SAE being downgraded to an alert by 10:15 a.m. RAT 1-B was re-energized at 11:40 a.m., restoring power to the "B" safety train. By 12:57 p.m., the "A" train transitioned from EDG to RAT 1-B, enabling shutdown of EDG and termination of the alert at 1:47 p.m.

During this incident, the core coolant temperature in Unit 1 increased from 90 °F to 136 °F over a period of thirty-six minutes. The plant’s electrical system lacked capability to connect vital buses to either non-vital or Unit 2 buses under these conditions. As a result, Plant Vogtle upgraded its infrastructure post-incident to allow non-vital buses to supply vital buses during similar events.

Unit 2 also experienced impacts when breakers in the switchyard tripped, disconnecting power to RAT 2-B and vital bus "B." Emergency diesel generator EDG 2-B started and restored power to the vital bus. A protective relay on Unit 2’s main step-up transformer opened its output breaker after sensing disturbance caused by the downed line, triggering a full load rejection, turbine trip, and reactor scram.

An attempt to transfer the "B" non-vital train from UAT 2-B to RAT 2-B failed, causing trips in two reactor coolant pumps and one main feedwater pump. Despite these events, safe cooldown procedures continued uninterrupted. By 9:03 p.m., RAT 2-B breakers were reset, offsite power was restored to both "B" trains, pumps were restarted, and EDG 2-B was shut down.

Investigation determined that the protective relay should not have tripped due to the fault disturbance; incorrect current transformer settings led to this unexpected shutdown. Controls were subsequently adjusted to prevent recurrence.

Planning stage

In August 2006, Southern Nuclear submitted an application for an Early Site Permit (ESP) for two new units, followed by filing for a Combined Construction and Operating License (COL) in March 2008. In April that year, Georgia Power contracted for two AP1000 reactors designed by Westinghouse, a subsidiary of Toshiba. Westinghouse collaborated with the Shaw Group on project management; Westinghouse took responsibility for engineering and design while Shaw oversaw manufacturing and on-site construction. This contract represented the first new nuclear development agreement in the United States since 1979. The Georgia Public Service Commission approved this contract in March 2009.

Construction

In August 2009, the Nuclear Regulatory Commission (NRC) granted an Early Site Permit along with a Limited Work Authorization, permitting restricted construction activities. Initially, Unit 3 was projected to become operational by 2016, followed by Unit 4 in 2017, contingent upon the final issuance of the Combined Operating License (COL).

A significant design modification occurred in December 2011 when the AP1000 Design Certification was updated, mandating a switch from a reinforced concrete containment building to one featuring a composite wall structure. This change resulted in construction setbacks since contracts had already been finalized and manufacturing processes were underway.

On February 16, 2010, President Barack Obama announced federal loan guarantees totaling $8.33 billion to support construction expenses. Despite this, Georgia Power initially postponed utilizing these guarantees pending outcomes related to licensing and legal proceedings. The project's overall estimated cost stood at $14 billion, with Georgia Power responsible for approximately $6.1 billion. Other stakeholders included Oglethorpe Power, Municipal Electric Authority of Georgia (MEAG Power), and Dalton Utilities.

Although the NRC approved the AP1000 construction license in February 2012, some dissenters raised safety concerns linked to the Fukushima incident. Environmental organizations filed lawsuits aiming to stop construction based on these safety issues; however, the D.C. Circuit Court dismissed these cases in July 2012.

In February 2013, Shaw was acquired by Chicago Bridge & Iron Company (CB&I). Official construction of Unit 3 commenced with the basemat concrete pour in March 2013. By June of that year, delays had extended the schedule by a minimum of 14 months. The basemat pour for Unit 4 was completed in November 2013.

The Department of Energy approved a $6.5 billion loan guarantee in February 2014 for Georgia Power and Oglethorpe Power Corp., waiving the initial credit subsidy fee due to Southern Company’s strong financial standing.

After additional delays and escalating costs surfaced in early 2015, CB&I withdrew from the project; Westinghouse assumed direct control and engaged Fluor Corporation to manage on-site operations. Westinghouse also acquired Shaw’s assets from CB&I to maintain progress. In 2016, Southern Company and Westinghouse brought Bechtel on board to share responsibilities for construction management.

Notable milestones included the installation of major structural components—known as the "big six"—within Unit 3’s containment vessel in May 2016, which facilitated subsequent construction phases. The final reactor coolant pump arrived in June 2016, followed by the installation of the reactor vessel in November. In 2017, Unit 3 advanced with installing reactor coolant loop piping and steam generators, while Unit 4 progressed with its last "big six" modules. By this stage, both cooling towers—each nearly tall—were completed.

Westinghouse Bankruptcy Filing in 2017

In March 2017, Westinghouse Electric Company initiated a Chapter 11 bankruptcy proceeding following significant financial setbacks linked to its two nuclear construction projects in the United States. The federal government extended $8.3 billion in loan guarantees to back the completion of the Vogtle reactors, accompanied by an agreed-upon strategy to finalize the plant. On July 31, 2017, Southern Nuclear, a subsidiary of Southern Company, assumed responsibility for construction from Westinghouse and issued requests for proposals to appoint a new construction management firm. By August 31, Southern selected Bechtel to oversee daily construction activities, replacing Fluor.

Approval for Construction Continuation, 2017

In November 2017, the Georgia Public Service Commission (GPSC) sought further documentation amid concerns regarding unapproved design plans. Subsequently, on December 21, the PSC authorized the ongoing construction of Units 3 and 4 under conditions that limited cost recovery from consumers, resulting in an anticipated $3.78 monthly rate increase after the units began generating power.

The Vogtle Construction Monitoring Report released in February 2018 projected operational start dates of November 2021 and November 2022 for Units 3 and 4 respectively, noting progress was ahead of schedule. However, by August 2018, project costs escalated by $2.3 billion, raising total estimates including financing to approximately $25 billion. In September, Georgia Power committed to covering expenses exceeding $9.2 billion to ensure project completion.

Federal loan guarantees were increased by $3.7 billion in March 2019, bringing total federal backing to $12 billion; Georgia Power’s CEO highlighted these guarantees as crucial for lowering financing expenses. That same month marked the installation of Unit 3’s containment cap with fuel loading planned for 2020. Key installations during 2018–2019 included the containment vessel’s third ring, reactor coolant pump, and polar crane. Visits from Secretary of Energy Rick Perry and plant leadership underscored milestones such as placing the containment vessel’s top head. Lessons learned from Unit 3 and the unsuccessful Virgil C. Summer Nuclear Generating Station project influenced modifications in Unit 4’s component installation sequence.

Important achievements toward late 2019 featured setting Unit 4’s containment vessel third ring on November 22, installing Unit 3’s shield building roof on December 8, and commissioning Unit 3’s control room on December 16. By February 2020, Southern Nuclear completed final concrete pours inside Unit 3’s containment vessel, facilitating installation of the reactor fueling machine. Work continued assembling the passive containment cooling system storage tank atop the shield building roof.

An announced delay of three months in October 2021 deferred Unit 3’s operational start to Q3 2022 and Unit 4’s to Q2 2023. Further postponements in August 2022 pushed Unit 3’s launch to Q1 2023 and Unit 4’s to Q4 2023, with total costs now expected to surpass $30 billion due to these delays.

Commissioning Phase

On October 14, 2022, Vogtle Unit 3 commenced nuclear fuel loading as technicians from Southern Nuclear and Westinghouse transferred a total of 157 fuel assemblies from the pool into the reactor core. Following fuel insertion, startup testing confirmed that primary coolant and steam systems met design specifications. Operators then advanced the unit from a cold shutdown state to first criticality, achieving a sustained nuclear chain reaction. The unit was subsequently synchronized with the electrical grid and power output was gradually increased to full capacity. Initial projections targeted commercial operation beginning in Q1 2023.

Unexpected vibrations detected during pre-operational testing in February 2023 delayed full service commencement until May or June of that year. On March 6, Vogtle Unit 3 achieved criticality for the first time, connected to the grid on April 1, and officially entered commercial operation on July 31.

On May 2, 2023, Georgia Power confirmed that Vogtle Unit 4 had successfully completed hot functional testing and was prepared for fuel loading. Fuel insertion started on August 18 with a total of 264 fuel assemblies. In October, a motor fault affecting a reactor coolant pump postponed Unit 4’s startup until Q1 2024; additional vibrations within the cooling system further delayed its service entry to Q2 of that year. Vogtle Unit 4 reached criticality on February 14, 2024, was connected to the grid on March 1, and commenced commercial operation on April 29.

Surrounding population

The Nuclear Regulatory Commission identifies two distinct emergency planning zones surrounding nuclear facilities: a 10-mile radius plume exposure pathway zone addressing airborne radioactive hazards, and a 50-mile ingestion pathway zone concerned with radioactive contamination in food and beverages.

As of 2010, the number of residents living within 10 miles of Vogtle was 5,845, representing a 16.3% decline compared to the previous ten years. The population residing within 50 miles totaled 726,640, reflecting an increase of 8.8% since 2000. Notable urban centers within this area include Augusta, situated approximately 26 miles away.

Reactors

Reactor Unit	Reactor Model	Capacity (MWe)		Construction Initiated	Grid Connection	Commercial Startup	Decommissioned
Reactor Unit	Reactor Model	Net (Summer)	Gross	Construction Initiated	Grid Connection	Commercial Startup	Decommissioned
Vogtle-1	Westinghouse 4-loop	1150	1229	August 1, 1976	March 27, 1987	June 1, 1987
Vogtle-2	Westinghouse 4-loop	1152	1229	August 1, 1976	April 10, 1989	May 20, 1989
Vogtle-3	AP1000	1117	1250	March 12, 2013	March 31, 2023	July 31, 2023
Vogtle-4	AP1000	1117	1250	November 19, 2013	March 6, 2024	April 29, 2024

Seismic risk

According to a Nuclear Regulatory Commission assessment conducted in 2010, the probability of an earthquake causing core damage at the Vogtle reactors is estimated at one in every 140,845 years.

External links