Imagine that the twin problems of foreign-oil dependence and atmospheric pollution from the burning of fossil fuels could be significantly reduced by bringing on line more of a commercial energy source already in common use. Would you not expect a big celebration? A rush by politicians and pundits to talk about its economic and environmental benefits?

You don't need to use your imagination. Nuclear power provides about 20 percent of the nation's electricity -- safely, economically and reliably. Its benefits are real and measurable. For example, nuclear power has played a central role in replacing oil in electricity generation, and it could do the same for transportation if plug-in electric vehicles catch on.

Unfortunately, there is little public discussion about the enormous benefits of expanding the use of nuclear power, let alone celebrations.

The great environmental advantage of nuclear power is that it produces no greenhouse-gas emissions or air pollution. The 104 U.S. nuclear power plants currently in operation account for more than 70 percent of the nation's emission-free electricity generation. Without electricity from nuclear plants, we would be burning substantially more coal and natural gas.

Energy needs in the United States are projected to grow in the coming decades, even with improved efficiency and conservation. The use of nuclear power in this country is on the rise, producing a record 807 billion kilowatt-hours of electricity last year, compared to 557 billion in 1990, adding the equivalent of 25 large power plants without fanfare.

Steady improvements in the safety and efficiency of nuclear plants over the past four decades have made this possible. Major reductions in the number of significant problems at America's nuclear plants, a plunging workplace accident rate and far fewer unplanned automatic plant shutdowns reflect increased attention to training and plant safety.

There has been only one plant shutdown of more than a year for safety reasons over the past decade, compared to 26 shutdowns from 1987 to 1997 and 21 in the decade before. Everyone involved in plant operations, from reactor operators to those responsible for refueling and spent-fuel management, receive rigorous and continuous training.

There also has been an improvement in efficiency. In 2007, nuclear plants, on average, were up and running at full power 91 percent of the time, compared to 62 percent in 1980 and 71 percent in 1990. Pennsylvania has some of the top-performing plants in the country. Between 2004 and 2006, plants operating more than 90 percent of the time included Beaver Valley 1 and 2, Limerick 1 and 2, Peach Bottom 2 and 3, Susquehanna 2, and Three Mile Island 1. Spent fuel is being stored safely at plant sites until it can be moved to the permanent repository planned for Yucca Mountain in Nevada.

To ensure safety, the Institute of Nuclear Power Operations -- which the industry established 25 years ago -- monitors each plant. Inspections typically run two weeks each, and the institute shares lessons learned from experience and technological advances with all nuclear plants. The U.S. Nuclear Regulatory Commission has at least two resident inspectors and as many as four posted at each nuclear site.

In recent years the NRC and the industry have made increased use of computer-based analyses of each plant, as well. Known as probabilistic safety analyses, they provide plant personnel and regulators with a valuable tool for zeroing in on what are the most important maintenance needs and safety risks at a plant. This vigilance has produced an outstanding safety record -- no one in the public has ever been harmed by the operation of a nuclear power plant in the United States. As a result, instead of nuclear plants being shut down after their initial license periods of 40 years, half have been re-licensed by the NRC for another 20 years. Almost all remaining plants have applied to the NRC to have their licenses renewed or intend to.

To date, utilities also have applied for licenses from the NRC for 15 new nuclear plants, with the first few ready for commercial service by 2015. More applications are anticipated during 2008 and 2009.

Once these plants are on-line, construction of another group of nuclear plants will be launched. These actions demonstrate that the nuclear industry is serious about providing reliable supplies of electricity that safeguard public health and protect the environment.