JENKINSVILLE — In a recently released year-in-review video posted to its YouTube channel, South Carolina Electric & Gas Company, principal subsidiary of SCANA Corporation, showcases the work accomplished in 2015 on its nuclear construction site at V.C. Summer Nuclear Station.
SCE&G and co-owner Santee Cooper are building two 1,117-megawatt Westinghouse AP1000 reactors. These are among the first being built in the United States in 30 years.
Once the two units are complete, SCE&G anticipates its generation mix will be about 30 percent nuclear, 30 percent natural gas, and 30 percent scrubbed coal, with the balance in hydro, solar and biomass.
The following is an overview of last year’s highlights on the construction site and in the community.
January 2015 featured delivery of the first AP1000 steam generators to arrive in the U.S. Each steam generator for V.C. Summer Unit 2 weighs more than 1 million pounds, measures 20 feet in diameter, and is more than 80 feet long.
Manufactured in Doosan, South Korea, arrival of the steam generators at the Port of Charleston goes on record as one of the heaviest energy project shipments for the South Carolina Ports Authority.
Pressurizers were among other major equipment deliveries. Manufactured in Italy, the Unit 2 pressurizer traveled by rail from the Port of Charleston and arrived on site in February.
Later in the year, the Unit 3 pressurizer was delivered. The 110-ton pressurizers will be housed inside the containment vessels, allowing water in the reactor coolant system to maintain high temperatures without boiling.
As work continued with structural modules, mechanical modules were also taking shape. Mechanical modules are racks that hold pumps, cable trays, pipes, conduits, valves or similar equipment. For example, the R151 mechanical module was completely assembled on the construction site.
This 20,000-pound module was placed in the Unit 2 nuclear island in March. Additional mechanical modules were placed later in the year.
The second quarter of 2015 closed with the achievement of two milestones within one week for V.C. Summer Unit 3. In June, workers placed the CA04 module on the containment vessel bottom head. CA04 is the reactor vessel cavity.
Standing approximately 27 feet tall and spanning 21 feet wide, CA04 is considered a super module because it is too large to transport fully assembled.
Also, the reactor vessel, which CA04 will house along with related components, was delivered to the construction site. Once CA04 is fully encased in concrete, the reactor vessel will be lowered into it and mounted on top.
In July, another major milestone was achieved: Safe and successful placement of the 2.4-million pound CA01 module within the Unit 2 containment vessel.
This multi-compartment steel structure will house a number of major components. CA01 is approximately 90 feet long, 95 feet wide, and 80 feet high. Because it was too large to transport, CA01 was assembled on the construction site in a 12- story Module Assembly Building.
This was the first Westinghouse AP1000 module of its kind to be placed in the U.S., and it is the heaviest lift on the V.C. Summer nuclear construction site. One of the world’s largest cranes, a heavy lift derrick that stands approximately 560-feet tall, was used to lift this massive module.
Just a few days before placing CA01, the first six-panel course of nearly 170 shield building panels was placed on Unit 2. Weighing 30,000 pounds and spanning 40 feet long, each panel is welded together, and then concrete is poured inside the panels to create the shield building.
Shield building work continues with two courses of panels now in place. When complete, this reinforced concrete structure will surround the containment vessel for another layer of safety.
The nuclear construction team concluded the year on a high note by placing the foundation for the Unit 2 turbine and generators. This heavily reinforced concrete deck is approximately 217 feet long, 49 feet wide and more than 10 feet thick, strengthened with 400 tons of steel bar. That adds up to nearly 2,400 cubic yards of concrete — roughly the equivalent of 250 concrete trucks — poured continuously in 20 hours.
While work continued steadily on the construction site, service in the community also occurred. This included continuing to support a neighboring healthcare facility, helping to make a local resident’s home of 50 years safer and more energy efficient, educating high school students about career opportunities in the nuclear industry, and providing tours of the nuclear construction site.
SCE&G is a regulated public utility engaged in the generation, transmission, distribution and sale of electricity to approximately 697,000 customers in South Carolina. The company also provides natural gas service to approximately 343,000 customers throughout the state. More information about SCE&G is available at www.sceg.com.
SCANA Corporation, headquartered in Cayce, is an energy-based holding company principally engaged, through subsidiaries, in electric and natural gas utility operations and other energy-related businesses. Information about SCANA and its businesses is available at www.scana.com.