RALEIGH, N.C. — Progress Energy customers and Wake County neighbors of the Shearon Harris nuclear power plant have the opportunity to speak out Tuesday about the proposal to expand the plant.

Dozens of people turned out at a public meeting Tuesday afternoon to discuss the environmental impact of a new reactor. Another meeting was scheduled for 6 p.m. at the Holly Springs Cultural Center at 300 W. Ballentine St.

Progress Energy officials said a growing customer base and a higher demand for power justify the expansion. The company expects to add 500,000 customers in the next 20 years.

Wake County leaders are on record in support of the plan. The school district approves. "Electricity is an infastructure that we need," Joe Bryan, chairman of the county Board of Commissioners, said.

Opponents say they need a closer look.

"We really need our elected officials to provide scrutiny for these type of projects," cautioned Jim Warren, head of the watchdog group N.C. Warn.

At Tuesday's meeting, residents cited the recent drought. "Where will you get the water to cool the reactors?" Jane Smith, a member of the Lee County Environmental Affairs Board, wanted to know.

A Holly Springs councilman asked about an evacuation plan. "There is a fear amoung citizens that should there be an emergency that inadequate roads will become gridlocked," he said.

The plant was originally planned to support four nuclear reactors, but only one was built.

The Harris site offers a large amount of available land -- approximately 35 square miles -- and has an ample water supply, Progress Energy said.

A final decision on whether to build the $2 to $3 billion reactor is still years away and will depend not only on public support, but on regulatory approval, predictions of energy demand and economic conditions, Progress officials said.

A new plant could be online as early as 2018 if the Nuclear Regluatory Commission approves.

North Carolina gets 32 percent of its power from five nuclear sites, 20 percent of which is supplied by Shearon Harris. Progress Energy has two other reactors in Brunswick County and Charlotte-based Duke Power has two reactors in Cornelius, north or Charlotte.

Nationwide, 20 percent of electricity comes from 103 commercial nuclear reactors operating in 31 states.