Nuclear power in the United States is provided by 99 commercial reactors with a net summer capacity of 98,621 megawatts (MW), consisting of 65 pressurized water reactors and 34 boiling water reactors, producing a total of 797 terawatt-hours of electricity, which accounted for 19.47% of the nation’s total electric energy generation in 2014. As of 2015, there are five new reactors under construction with a gross electrical capacity of 6,218 MW, while 33 reactors have been permanently shut down. The United States is the world’s largest supplier of commercial nuclear power, and in 2013 generated 33% of the world’s nuclear electricity.
In October 2014, the NRC has granted license renewals providing a 20-year extension to a total of 74 reactors. However, no applications for an additional license renewal, which could extend nuclear plant operating lives beyond 60 years, have yet been filed. For about 22 reactors license is due to expire before the end of the next decade if no renewals are granted. The Vermont Yankee Nuclear Power Plant was the most recent nuclear power plant to be decommissioned on December 29, 2014. Another four aging reactors were permanently closed in 2013 before their licenses expired because of high maintenance and repair costs at a time when natural gas prices have fallen: San Onofre 2 and 3 in California, Crystal River 3 in Florida, and Kewaunee in Wisconsin, and New York State is seeking to close Indian Point in Buchanan, 30 miles from New York City.
Most reactors began construction by 1974; following the Three Mile Island accident in 1979 and changing economics, many planned projects were canceled. More than 100 orders for nuclear power reactors, many already under construction, were canceled in the 1970s and 1980s, bankrupting some companies. Up until 2013, there had also been no ground-breaking on new nuclear reactors at existing power plants since 1977. Then in 2012, the NRC approved construction of four new reactors at existing nuclear plants. Construction of the Virgil C. Summer Nuclear Generating Station Units 2 and 3 began on March 9, 2013. A few days later, on March 12, construction began on the Vogtle Electric Generating Plant Units 3 and 4. In addition, TVA’s new reactor at the Watts Bar Nuclear Generating Station is at an advanced stage, after construction was resumed after being halted in 1988.
There was a revival of interest in nuclear power in the 2000s, with talk of a “nuclear renaissance”, supported particularly by the Nuclear Power 2010 Program. A number of applications were made, but facing economic challenges, and later in the wake of the Fukushima Daiichi nuclear disaster, most of these projects have been cancelled, and as of 2012, “nuclear industry officials say they expect five new reactors to enter service by 2020 – Southern’s two Vogtle reactors, two at Summer in South Carolina and one at Watts Bar in Tennessee”; these are all at existing plants. As of August 2013, there are construction delays at Vogtle and Summer.