U.S. nuclear energy facilities generated electricity at a record level of efficiency in 2014, demonstrating nuclear energy's value to the reliability and stability of the electric grid and to the nation's economy.

The 100 nuclear power plants operating in 31 states posted an estimated average capacity factor of 91.9 percent, based on preliminary 2014 data compiled by the Nuclear Energy Institute (NEI). That mark surpassed the industry's prior record set in 2007. Capacity factor measures total electricity generated as a percentage of year-round potential generation.

Actual electricity production from nuclear energy facilities last year was the sixth-highest ever at an estimated 798.4 billion kilowatt-hours (kWh). The industry's record high electricity generation came in 2010, when the 104 reactors then operating produced 806.9 billion kWh of electricity while posting an industry average capacity factor of 90.9 percent.

"The 2014 numbers show unequivocally how important well-performing nuclear energy is to America's energy security, the economy and our quality of life," said NEI president and chief executive officer Marvin Fertel. "Thanks to the hard work and dedication of the highly skilled men and women who work at these facilities, at the reactor vendors who provide support services, and in other capacities, U.S. nuclear power plants continue to operate at high levels of safety while generating affordable electricity that our society and our economy rely on."

For the past two decades, U.S. nuclear energy facilities have produced about one-fifth of U.S. electricity supplies, even as total electricity demand has increased significantly.

For more information, visit www.nei.org.