The Calvert County commissioners have thrown their support behind plans to build a new nuclear reactor in the county.

The five-member Board of County Commissioners voted unanimously Tuesday to urge a national consortium of electricity companies to select the county as the site of what could become the first nuclear reactor built to generate electric power in the United States in 30 years.

The Calvert Cliffs Nuclear Power Plant in Lusby is one of six sites the consortium, NuStart Energy Development LLC, is considering as a location for a new type of advanced reactor. NuStart plans to apply to the U.S. Nuclear Regulatory Commission for licenses to build and operate plants at two of the six sites under review.

"Supporting the expansion of Calvert Cliffs was not a difficult decision," the commissioners wrote in a letter to NuStart. "Calvert Cliffs plays a vital role in the County and State Economy."

The existing nuclear power plant is the largest taxpayer and private employer in Calvert County. It paid $15.3 million in property taxes last year -- almost 10 percent of the county's revenue -- and employs about 1,000 workers.

Linda S. Vassallo, director of the county's Department of Economic Development, said the county and state intend to consider a package of financial incentives to persuade NuStart to select Calvert as a site for a new reactor.

The package "will demonstrate to NuStart that Calvert County and the State of Maryland stand ready to provide assistance and support in locating a new reactor at Calvert Cliffs," the commissioners' letter said. Vassallo said details of the package will be final by Aug. 15 but will not be made public because they are part of the county's business negotiations.

Marilyn Kray, president of NuStart, said all the sites being considered by the consortium enjoy strong support from their local communities. That's why the package of financial incentives or tax breaks offered by local and state government could have a significant effect on the consortium's selection of a site.

"That could differentiate one site from another," she said.

County officials said they will make their pitch directly to NuStart when consortium officials visit Calvert County on Aug. 9.

The commissioners spent much of Tuesday's meeting praising officials from Baltimore-based Constellation Energy, which owns the Calvert Cliffs facility. They said jobs and taxes from the plant, which went online in 1975, helped transform Calvert County from one of the poorest counties in Maryland to one of the more affluent.

The board was equally lavish in its praise of the plant's commitment to community service. George Vanderheyden, site vice president for the plant, said Calvert Cliffs employees volunteered 4,300 hours of time and raised $330,351 for local charities in 2004.

"I just want to thank you for being such a good corporate neighbor," said Commissioner Gerald W. Clark (R-Lusby).

No one spoke against the proposed expansion at Calvert Cliffs. Local opposition to the nuclear power plant is almost nonexistent.

But Jim Riccio, a nuclear policy analyst with the environmental organization Greenpeace, said anti-nuclear activists from around the nation will descend in protest on whatever sites are chosen by NuStart.

"Calvert County has never seen the type of demonstrations that would occur if it was one of the two sites picked," he said. "I would guess that you are going to see massive civil disobedience."

NuStart plans to select the two sites by Oct. 1. Consortium officials want the new reactors to be operating by 2014.