The importance of the nuclear power industry to the nation's energy security is becoming increasingly clear. Nuclear energy is the only large-scale, carbon-free electricity source that the country can widely expand to produce large amounts of electricity. Noting that, nuclear power plants prevent the release of significant quantities of emissions that would be created by burning fossil fuels to generate the same amount of electricity. The current fleet of U.S. nuclear power plants eliminates the release of about 1 million short tons of nitrogen oxides and 2.7 million short tons of sulfur dioxide - pollutants controlled under the Clean Air Act - each year. They also prevent the emission of nearly 700 million metric tons of carbon dioxide each year; an amount nearly equal to that released from all U.S. passenger cars. The amount of nitrogen oxide emissions nuclear plants prevent annually is the equivalent of taking more than 47 million passenger cars off the road.