Vogtle Electric Generating Plant, Burke County, Georgia, United States of America
Alvin W Vogtle Electric Generating Plant, or Plant Vogtle, is located in Burke County near Waynesboro, Georgia, US.
Plant Vogtle is jointly owned by Georgia Power (45.7%), a subsidiary of Southern Company, Oglethorpe Power (30%), Municipal Electric Authority of Georgia (22.7%) and Dalton Utilities (1.6%). It is operated by the Southern Nuclear Operating Company.
The Vogtle Electric Generating Plant is spread across 3,200 acres around the Savannah River. It includes units 1 and 2, which became operational in 1987 and1989 respectively. Units 1 and 2 have a combined capacity of 2,450MW, which provides sufficient electricity for 600,000 homes.
In February 2012, the US Nuclear Regulatory Commission had approved the construction and operation of units 3 and 4. The two units are the first nuclear plants to be approved in the US since the Three Mile Island plant accident in 1979.
The commercial operation of Unit 3 is anticipated to begin in the fourth quarter of 2021 and Unit 4 in the fourth quarter of 2022.
Finances and budget escalation after 1979 Three Mile Island incident
Units 1 and 2 of the Vogtle Electric Generating Plant were built at a cost of approximately $8.87bn. The partial meltdown of the Three Mile Island nuclear plant in the state of Pennsylvania in 1979 caused the initial budget, of $668m, to increase to $8.87bn owing to new safety measures and designs.
The estimated cost for constructing units 3 and 4 is $19bn. In 2010, the US Government granted the Southern Company an $8bn loan guarantee for the construction of the two units.
Units 1 and 2 of Plant Vogtle
Tlant Vogtle was named after Alvin W Vogtle Jr, a former CEO of the Southern Company. Construction on the two units began in 1974 but was suspended due to monetary problems.
Construction restarted in 1977. The two units were originally licensed until 2027 and 2029 respectively. In 2009, the licences were renewed until 16 January 2047 and 9 February 2049. The units employ more than 800 workers.
The two units were designed and constructed by the Bechtel Power Corporation and Southern Company Services.
Components of units 1 and 2 and using water from the Savannah River
The Plant Vogtle containment is a cylindrical structure measuring 140ft in diameter and 226ft-high. It has 4ft-thick walls and its interiors are layered with carbon steel plate.
The plant has two 355t reactor vessels on the ground level. Two 548ft-high cooling towers release non-radioactive water vapour. Other components include turbines, generators, a computerised control room, four reactor coolant pumps, high-voltage switchyards and a chemistry lab.
The plant receives water for cooling the condenser from the Savannah River. The two units make use of 1% of the average annual flow from the river.
Units 3 and 4 of Georgia's Alvin W Vogtle Electric Generating Plant
Georgia Power applied for certification of the two latest units with the Georgia Public Service Commission (PSC) in August 2008. The early site permit for constructing the units was granted by the NRC in August 2009, after which the groundwork started.
After a series of applications and approvals, the units were cleared by NRC in 2012. The approval was, however, not free of controversy, as the chairman of the commission voted negatively, citing the Fukushima accident in Japan in 2011.
Georgia Power filed a recommendation with the Georgia PSC to complete the construction of third and fourth units of the plant, in August 2017.
Construction of the two units is underway. The units are expected to have a capacity of 1,100MW each. The project management, engineering, procurement and construction (EPC) contract for the two units was awarded to CB&I and Westinghouse.
The CA20 module weighing more than 998t was installed into the Unit 3 nuclear island in March 2014. The module is 67ft-long and 47ft-wide, and accommodates various plant components, including the used fuel storage area.
The 460t CR10 module (or cradle) was placed into the Unit 4 nuclear island in February 2014. The Unit 4 containment vessel bottom head (CVBH), weighing over 816t, was placed into the unit's nuclear island in May 2014. The component is approximately 38ft-long and 130ft-wide and consists of dozens of individual steel plates. The CVBH rests on the CR10 module, which replicates a concave bowl with a hollow centre.
A 55-mile long, 500kV transmission line will be built by 2018 to support the two new units. It will begin at Plant Vogtle and end at the Thomson Primary substation.
PWRs used in Vogtle's units and US NRC certification
Vogtle units 1 and 2 use one four-loop pressurised water reactors (PWR), each supplied by Westinghouse Electric. The turbine generators were supplied by GE.
The new units 3 and 4 will each feature AP1000 PWRs designed by Westinghouse.
AP1000 reactor is a generation 111+ design, certified by the NRC. The simplified plant design accelerates the construction time to 36 months.