Using one of the world’s largest cranes, construction teams near Waynesboro, Ga., are making steady progress on a $14 billion project that involves building two more nuclear units at the Vogtle Electric Generating Plant. The additions of Vogtle Units 3 and 4 will reportedly create roughly 5,000 onsite construction jobs and 800 permanent jobs, and will allow the Vogtle site to generate more electricity than any other U.S. nuclear energy facility.
“We are building an advanced facility that is on the leading edge of technology and safety,” said Mark Williams, spokesman of Georgia Power. “These are among the first new nuclear units being built in the United States in the past 30 years. Once complete, they will provide enough clean, reliable, safe and affordable energy to power 500,000 Georgia homes and businesses.”
Vogtle sits on a 3,200-acre site along the Savannah River, in Burke County about 30 mi. (48.3 km) southeast of Augusta, Ga. The plant has large turbines and generators, a computerized control room, a chemistry lab and is connected to the electric grid through high-voltage switchyards. Containment buildings featuring thick walls of concrete and steel, house two 355-ton (322 t) reactor vessels on giant concrete slabs. The concrete structures shield the environment from radiation, and the 548 ft. (167 m) twin cooling towers can be seen for miles.
Roughly 900 people including engineers, mechanics and control room operators, lab technicians and security officers oversee the plant’s operations 24 hours a day.
Full-time, onsite inspectors from the U.S. Nuclear Regulatory Commission monitor the plant to ensure it is maintained and operated safely, efficiently and in accordance with established nuclear operating procedures.
As part of the expansion, Chicago Bridge and Iron (CB&I) had the massive task of fabricating the containment vessels and the cradles, as well as designing and building several other parts of the project. CB&I recently acquired the Shaw Group, which served as construction partner since the beginning of the project.
The first nuclear concrete placement was completed in March 2013. The CR-10 module, known as the “cradle,” was placed in April 2013. The Unit 3 containment vessel bottom head assembly and turbine island lower foundation work is complete. Upper foundation work is progressing and on schedule. The Unit 3 cooling tower is currently more than 40 percent finished. Design engineering activities for the facility and procurement of major components are both nearly complete.
Placing the first nuclear island concrete on Unit 3, to create the six-ft. (1.8 m) thick basemat was important. It serves as the foundation for the nuclear island, and includes the containment and auxiliary buildings. The placement of this basemat concrete is considered a crucial step, as it precedes the setting of key components inside the nuclear island.
“This historic moment marks yet another important milestone of the Vogtle expansion project and reflects the tremendous progress we’ve made at the site,” said Buzz Miller, executive vice president of Georgia Power Nuclear Development. “We are very proud of this accomplishment, and of all the hard work and collaboration that went into making it happen.”
The basemat covers 1,100 tons (99.8 t) of steel rebar and required 6,850 cu. yds. (6,263.6 cu m) of concrete to cover the area, 254 ft. (77.4 m) long and 161 ft. (49 m) across at its widest section. As a nuclear grade concrete, it was specially designed, mixed, reinforced and constructed according to strict procedures and a trained workforce with special certifications to perform the activity. Planning for the process was so strict that a mock site was constructed to simulate the concrete placement before it occurred.
Once the basemat for Unit 3 was finished, the cradle that will hold the bottom head of the Unit 3 containment vessel was placed inside the nuclear island. A 560 ft. (170.7 m) long heavy lift derrick was used during the process. The derrick has been used to move a number of large pieces at the site, with the capacity to transfer the equivalent of five 747 jets across the distance of more than three-and-a-half football fields in a single lift.
The basemat concrete placement was completed in approximately 41 hours. The placement at Vogtle Unit 3 encompassed approximately 7,000 cu. yds. (5,351.8 cu m) of concrete, and will serve as the foundation for all of the nuclear island structures, including the containment vessel and the shield building. It covered an area approximately 250 ft. (76.2 m) long and 160 ft. (48.8 m) wide at its widest point, and the concrete measured six ft. (1.8 m) thick.
“I congratulate the hundreds of workers who supported the first concrete pour at Vogtle Unit 3 in Georgia, which sets the stage for the installation of key modules in the unit’s nuclear island,” said Danny Roderick, president and CEO of Westinghouse Electric Company. “This is an important milestone for our customer, Southern Nuclear, and Westinghouse is honored that our AP1000 plant technology will enable Southern and its partners to meet the future energy needs of the citizens they serve.”
CR-10 was the first major module to be set in place at the site and is the first installed heavy lift.
“The safety processes and planning used to design the rigging have been going on for months,” said David Keech of Georgia Power. “A lot of upfront work was performed to ensure everything was where it was supposed to be and the lift was performed safely. In order to move a structure like that, it actually takes a rigging plan that’s above and beyond even the containment vessels. The weight had to be equalized to ensure there was no undo stress put on the individual structural members as it was being lifted, swung and set.”
Permanent buildings and structures are taking shape, with work progressing around the cooling towers. The first X-braces have been put in place at a rate of one per day, marking the erection of the first above-ground permanent structures. Other permanent buildings going up that will eventually be shared by all four Vogtle units are for maintenance, security, operations offices and support functions. These will make up this inner area known as the “central campus.” The new permanent buildings will eventually replace the office complexes where Georgia Power, Westinghouse, Southern Nuclear, CB&I and other employees are currently located. The modular assembly building and other temporary structures will be removed once the project is complete.
“The project is progressing extremely well, especially when compared to other large-scale infrastructure projects worldwide,” said Miller. “The Vogtle 3 and 4 project provides at least $2.2 billion more value to customers than the next best available technology, according to Georgia Public Service Commission staff.”
Southern Nuclear, a subsidiary of Southern Company, is overseeing construction and will operate the two new 1,100-mW AP1000 units for Georgia Power and co-owners Oglethorpe Power Corporation, the Municipal Electric Authority of Georgia and Dalton Utilities. Georgia Power owns 45.7 percent of the new units, with a certified cost of $6.1 billion. The company serves 2.4 million customers.
Plant Vogtle houses two nuclear reactor units that began operation in the late 1980s. Each unit can generate 1,215 mW, for a combined capacity of 2,430 mW. Power is generated using pressurized water reactors manufactured by Westinghouse, and the turbines and electric generators were manufactured by General Electric. The plant is one of three in the Southern Company.
Unit 3 is scheduled to go on line in 2017, and Unit 4 will follow in 2018. Georgia Power actually filed an Application for Certification of Vogtle Units 3 and 4 with the Georgia Public Service Commission back in 2008. The Georgia PSC granted approval to implement the proposed Vogtle expansion in 2009. In April, 2009, Vogtle Units 3 and 4 were named the U.S. nuclear industry reference plant for the AP1000. As the reference plant, these units will be the first in America licensed to operate using AP1000 technology.
The construction of Vogtle 3 and 4 is the largest job-producing project in Georgia. The project has not been without its share of controversy. At last report, construction spending is more than $380 million over budget and additional overruns are possible. Federal lawsuits have been filed, and the Georgia Women’s Action for New Directions, an anti-nuclear group, has called for an end to the project. But construction continues at the site, with no signs of slowing down. In fact, one third of the work has already been completed.
“Our goal is to build the safest, most reliable facility possible, one that will deliver clean and affordable energy for decades to come,” said Williams.