It's been more than 20 years since a new nuclear reactor came online in New York. That could soon change.

Unistar, a partnership between Constellation Energy and the French company AREVA, is proposing a new reactor at Nine Mile Point just outside of Oswego. The plant would produce 1,600 megawatts, reports the Syracuse Post-Standard - a single megawatt can power up to 1,000 homes. Unistar told the Nuclear Regulatory Commission that it plans to apply for the expansion this year, says the Post-Standard. The licensing process is expected to take up to four years.

This would be the fourth nuclear reactor for the Oswego area - there are two at Nine Mile Point and there's the James A. FitzPatrick plant. Statewide, there are six reactors, including the one at Ginna in Ontario, Wayne County.

Building a new nuclear plant is a complex proposition. The plants are expensive to build, though a mixture of federal incentives such as loan guarantees and production tax credits have made cost less of an issue. And safety and environmental concerns remain.

"I think it's going to be a huge fight," says Tom Drennen, a Hobart and William Smith Colleges professor who studies energy issues. "People will come out of the woodwork to protest nuclear again."

There is no national facility for storing nuclear waste. The waste that's been generated at Nine Mile Point remains on-site, he says.

Increased climate change awareness, however, could work in nuclear's favor. New York and other northeastern states this year started a new carbon dioxide cap and trade program for power plants. Power companies may look to nuclear plants as a long-term approach to meeting government emissions targets.

Many environmentalists remain opposed to the plants - waste storage issues, high-volume water use, and environmental damage and greenhouse gas emissions from uranium mining are among their objections. But some environmentalists have shifted on nuclear, namely because the reactors emit less greenhouse gases than coal or natural gas plants.

And while many environmentalists are not warming to nuclear power, they are curious. Case in point: the Federation of Monroe County Environmentalists is developing plans for a nuclear power forum this spring.