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 coul...