PROVIDENCE, R.I. (AP) -- As climate change pushes states in the U.S. to dramatically cut their use of fossil fuels, many are coming to the conclusion that solar, wind and other renewable power sources might not be enough to keep the lights on.
Nuclear power is emerging as an answer to fill the gap as states transition away from coal, oil and natural gas to reduce greenhouse gas emissions and stave off the worst effects of a warming planet. The renewed interest in nuclear comes as companies, including one started by Microsoft founder Bill Gates, are developing smaller, cheaper reactors that could supplement the power grid in communities across the U.S.
Nuclear power comes with its own set of potential problems, especially radioactive waste that can remain dangerous for thousands of years. But supporters say the risks can be minimized and that the energy source will be essential to stabilize power supplies as the world tries to move away from carbon dioxide-emitting fossil fuels.
Tennessee Valley Authority President and CEO Jeff Lyash puts it simply: You can't significantly reduce carbon emissions without nuclear power.
"At this point in time, I don't see a path that gets us there without preserving the existing fleet and building new nuclear," Lyash said.
The federally owned utility is adding solar capacity, but also operates three nuclear plants and plans to test a small reactor. By 2050, it hopes to become net zero, which means the amount of greenhouse gases produced is no more than the amount removed from the atmosphere.
An Associated Press survey of the energy policies in all 50 states and the District of Columbia found that a strong majority-- about two-thirds-- say nuclear, in one fashion or another, will help take the place of fossil fuels. That momentum could lead to the first expansion of nuclear reactor construction in the U.S. in more than three decades.
Roughly one-third of the states and the District of Columbia say they have no plans to incorporate nuclear power in their green energy goals, instead leaning heavily on renewables. They pointed to advances in energy storage using batteries, investments in the grid for high-voltage interstate transmission, energy efficiency efforts to reduce demand and power provided by hydroelectric dams.
The split over nuclear power mirrors a similar debate unfolding in Europe.
The Biden administration has tried to take aggressive steps to reduce greenhouse gases in the U.S. The $1 trillion infrastructure package passed last year will allocate about $2.5 billion for advanced reactor demonstration projects.
U.S. Energy Secretary Jennifer Granholm told the AP the administration wants to get to zero-carbon electricity, and that means nuclear, hydropower, geothermal, wind and solar.
"We want it all," she said.
Nuclear technology still comes with significant risks that other low-carbon energy sources don't, said Edwin Lyman, director of nuclear power safety at the Union of Concerned Scientists. He's concerned the industry might cut corners on safety and security to save money and compete. The group does not oppose using nuclear power, but wants to make sure it's safe.
The U.S. also has no long-term plan for managing or disposing the hazardous waste, and there remains the danger of accidents or targeted attacks, Lyman said. Nuclear disasters at Pennsylvania's Three Mile Island, Chernobyl and more recently, Fukushima, Japan, in 2011 provide an enduring warning.
Nuclear power already provides about 20% of electricity in the U.S., or about half the nation's carbon-free energy.
The Nuclear Regulatory Commission has approved just one of the new, small modular reactor designs -- from NuScale Power in 2020. Gates' company, TerraPower, wants to build an advanced reactor in Wyoming, which has long depended on coal for power and jobs.
As utilities quit coal, Wyoming is tapping into wind. But Glen Murrell, executive director of the Wyoming Energy Authority, said it's unrealistic to expect all the nation's energy to be provided exclusively through wind and solar.
Georgia maintains that its nuclear reactor expansion will provide "ample clean energy" for 60 to 80 years. New Hampshire said the region's environmental goals would be impossible to meet as affordably without nuclear. Energy agencies in Alaska and Maryland are planning for small modular nuclear reactors.
Other officials, mostly in Democratic-led states, said they're moving beyond nuclear power. Some said they never relied heavily on it to begin with and don't see a need for it.
They said the cost of new reactors compared to installing wind turbines or solar panels, the safety concerns and the unresolved question of how to store hazardous nuclear waste are deal-breakers. Some environmentalists oppose small modular reactors for similar reasons.
New York's future energy grid will be dominated by wind, solar and hydropower, said New York State Energy Research and Development Authority President and CEO Doreen Harris.
Nevada officials don't consider nuclear power a viable option because of the failed plan to store the nation's commercial spent nuclear fuel at Yucca Mountain. Instead, they see potential for energy storage and geothermal energy.
"A focus on short-term gains can't alleviate the long-term issues with nuclear energy," David Bobzien, director of Nevada Governor's Office of Energy, said in a statement.
California is slated to close its last remaining nuclear power plant, Diablo Canyon, in 2025, as it turns to cheaper renewables to power its grid by 2045. Officials plan to sustain the expansion of clean electricity generation at a record-breaking rate. California also imports power from other states.
Skeptics have questioned whether the plan can work in a state of nearly 40 million people. Jason Bordoff, co-founding dean of the Columbia Climate School, said there is "good reason" to think about extending the life of Diablo Canyon to keep energy costs down and reduce emissions quickly.
Nuclear energy isn't risk free, he said, "but the risks of falling short of our climate goals exceed the risks of including nuclear energy as part of the zero carbon energy mix."