Democrats, environmentalists warm to nuclear power for quicker transition to a green energy future

Nuclear power, once shunned by many Democrats and environmentalists, is gaining acceptance among the party and activists as a clean alternative to fossil fuels amid soaring energy costs and a sluggish transition to renewables.

Proponents argue that the carbon-free energy source is clean and affordable, can be generated around the clock and is already prevalent. Wind and solar power, meanwhile, are intermittent and hamstrung by limited battery storage capabilities.

“There’s been a slow progression, but sufficient modeling that has been done has convinced a lot of people in the environmental...