Resources & Stats

U.S. Nuclear Power Plants

General Statistical Information

Nuclear energy provides 19.2 percent of the United States' electricity and is its No. 1 source of emission-free electricity.  

Number of operating reactors:
104 (35 boiling water reactors, 69 pressurized water reactors)
  • 14 BWR plants have one reactor; nine have two reactors; one has three reactors
  • 15 PWR plants have one reactor; 24 have two reactors; two have three reactors
  • For reactors by state, see U.S. Nuclear Operating Plant Basic Information.

Companies licensed to operate nuclear reactors:

Number of states with operating reactors
: 31
In seven states for 2010, nuclear makes up the largest percentage of their electricity generated:

State Percent
Vermont    73.3
Connecticut   50.3
New Jersey    49.9
South Carolina    49.9
New Hamphshire   49.1
Illinois    47.8
Virginia    36.3

Largest U.S. nuclear plant:

Palo Verde (Arizona): 3 reactors at 1,311 / 1,314 / 1,317 megawatts (MW) each for a total of 3,942 MW

Smallest U.S. nuclear plant:
Ft. Calhoun (Neb.): 1 reactor at 478 MW

Newest nuclear plants:
  • June 1996: Watts Bar 1 in Tennessee, 1,123 MW
    (Tennessee Valley Authority)
  • August 1993: Comanche Peak 2, 1,158 MW
    (TXU Electric Co.)
  • August 1990: Comanche Peak 1, 1,209 MW
    (TXU Electric Co.)
  • August 1990: Seabrook 1 in New Hampshire, 1,247 MW
    (FPL Group, Inc.)
  • January 1990: Limerick 2 in Pennsylvania, 1,134 MW
    (Exelon Corp.)

Oldest operating nuclear plant/year:
Oyster Creek in New Jersey, operating license issued April 1969

Reactor Manufacturers:
* ABB's worldwide nuclear businesses were acquired by Westinghouse on May 2, 2000. The former ABB-CE fuel fabrication facility in Hematite, MO, will be closed over an 18-month period and most of the company's U.S. fuel operations will be consolidated at the existing Westinghouse facility in Columbia, S.C.

Nuclear Generation and Capacity

Percent of total U.S. electricity generation in 2011:
19.2% or 790.2 billion kilowatt-hours (bkWh).

Percent of worldwide electricity:
14% or 2,628 billion kilowatt-hours (bkWh) in 2010.

Industry capacity factor (2011):
There has been an upward trend in the capacity factor for U.S. commercial nuclear power plants since the 1980s.
Amount of electricity generated by a 1,000-MWe reactor at 90% capacity factor in one year:

7.9 billion KWh—enough to supply electricity for 740,000 households.

If generated by other fuel sources, it would require:
  • Oil: 13.7 million barrels – 1 barrel yields 576 KWh
  • Coal: 3.4 million short tons – 1 ton yields 2,297 KWh
  • Natural Gas: 65.8 billion cubic feet – 100 cubic feet yields 12 KWh
    (based on average conversion rates from the Energy Information Administration)

Nuclear Plant Performance

Longest Operating Period Between Refuelings:
LaSalle 1 (Illinois); 739 days; February 2006

Most Electricity Generated:

South Texas Project 2 (Texas); 11.8 billion KWh; 2007

Nuclear Power Uprates
For definitions, types and regulations on power uprates see Power Uprates (U.S. NRC) .

The process of increasing the maximum power level at which a commercial nuclear power plant may operate is called a power uprate. Power uprates at nuclear plants are very common and require additional capital investment.

More than 6,000 MW of power uprates have been approved by the NRC since 1977. That is the equivalent of adding another five to six nuclear reactors.
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