part of an agreement to end an investigation into Duke's Progress Energy acquisition in 2012. In 2016, Duke Energy purchased Piedmont Natural Gas for $4.9 billion to become its wholly owned subsidiary. Duke Energy completed selling its remaining power operations in Central and South America for $1.2 billion months afterwards. At one point Duke Energy had more than 4,300 megawatts of electric generation in Latin America. It operated eight hydroelectric power plants in Brazil with an installed capacity of 2,307 megawatts. The company expects to spend $13 billion upgrading the North Carolina grid from 2017. On December 3, 2022, an attack was carried out on two Duke Energy substations located in Moore County, North Carolina. Damage from the attack left up to 40,000 residents without electrical power for several days, with officials closing schools and declaring a state of emergency. The Federal Bureau of Investigation supported local investigators in case the incident met the definition of domestic terrorism under the Patriot Act. New nuclear power plant On March 16, 2006, Duke Power announced that a Cherokee County, South Carolina site had been selected for a potential new nuclear power plant. The site is jointly owned by Duke Power and Southern Company. Duke plans to develop the site for two Westinghouse Electric Company AP1000 (advanced passive) pressurized water reactors. Each reactor is capable of producing approximately 1,117 megawatts. (See Nuclear Power 2010 Program.) On December 14, 2007, Duke Power submitted a Combined Construction and Operating License to the Nuclear Regulatory Commission, with an announcement that it will spend $160 million in 2008 on the plant with a total cost of $5 billion to $6 billion. The plant was approved in 2016. In August 2017, Duke decided to seek permission from the North Carolina Utility Commission to cancel the project due to the bankruptcy of Westinghouse and "other market activity", although they will retain the option of restarting the project at some point in the future if circumstances change. This site would have been adjacent to the old site, which was never completed and abandoned in the early 1980s, and used by James Cameron as a film set for the 1989 movie The Abyss. In 2018, Duke Energy decided not to include new nuclear power in its long-range plans. Headquarters buildings J.A. Jones designed the first headquarters building, known as the Power Building, which was completed in 1927 at 440 South Church.