CHAMPAIGN, Ill. — The man in charge of the country's nuclear regulatory agency says the United States needs a generation of new scientists, engineers and skilled workers to staff, build and monitor what could be dozens new power plants.

The country is on the verge of a building boom for nuclear plants, but after almost three decades of inactivity, it's just starting to train the workers it will need, according to Dale Klein, the chairman of the Nuclear Regulatory Commission.

"We need to increase the talent pool across the board, all the way from Ph.D.s to skilled craft," Klein said.

Power companies have submitted applications to the NRC for 20 new reactors, and Klein expects about 10 more by the end of 2009.

A combination of ever-increasing demand for power, concerns about global warming and the costs of fossil fuels are driving much of the increase.

Those plans are meeting head on with an aging work force, creating the need for thousands of new nuclear industry workers.

The Nuclear Energy Institute last year estimated the industry could lose almost 20,000 workers, 35 percent of its work force, to retirement by the end of 2012. More than 6,000 more workers are expected to be lost to attrition.

The institute isn't sure how many more workers will be needed to staff new plants because there's no way to know how many of those 30 applications to build reactors will lead to construction. It estimates four to eight new reactors will be built by 2016, spokesman John Keeley said.

Companies that build the plants and their components also will need to hire new workers. Colleges will need more professors, and the NRC itself will need more people to consider applications and monitor plants.

The NRC recently handed out $20 million in grants to 60 American universities for faculty development and scholarships.

"The pipeline is not what it should be. The number of nuclear engineering programs has declined," NRC spokesman Scott said.

Accidents at Three Mile Island in Pennsylvania and Chernobyl in the Soviet Union dampened American interest in new nuclear plants through the 1980s and '90s. The country has about 104 nuclear reactors.

"Several years ago we would sarcastically say you can't mention nuclear in public," Klein said.

With that public attitude toward nuclear power, the bottom dropped out of the job market for nuclear-related jobs, said James Stubbins, head of Illinois' Department of Nuclear, Plasma and Radiological Engineering.

"Ten years ago, students didn't see a career," he said. "To be honest, the university was thinking about shutting the program down. Many of the programs that were around closed."

Now, Illinois and the other roughly 30 American universities that offer nuclear engineering degrees are turning out more graduates.

According to the Department of Energy's Oak Ridge Institute for Science and Education, 729 people earned undergraduate and graduate degrees in nuclear engineering in 2007. That's almost double the 366 who did so in 2000.

At Illinois, 174 students are enrolled in the nuclear engineering program this fall, Stubbins said. In the late 1990s, fewer than 10 students were enrolled in any given year.

Many of the companies planning to build reactors say they're already working with universities and trade schools to train and recruit a range of employees — everything from nuclear and civil engineers to welders and people with business degrees, according to Mike Cleary of St. Louis-based Ameren Corp. The company has applied to add a reactor to its 1,190-megawatt nuclear Callaway plant in Missouri.

Ameren projects the additional reactor would increase the plant's work force from the current 750 to 1,150.

"It would be people across the spectrum, a wide range of skills," Cleary said.

The company also tries to steer high school students toward nuclear-related fields through speaker appearances at schools, and brings college students to the plant for summer work, spokeswoman Susan Gallagher said.