For the first time in 34 years, the U.S. Nuclear Regulatory Commission cleared the way for licensing of new nuclear reactors in the United States.

It’s not the first step for the addition to the Vogtle site outside of Augusta, Georgia, which four years ago began what was supposed to be a streamlined approval process. Nor is it the last step—Southern Company may still face lawsuits aimed at blocking the $14 billion project, and must overcome the industry’s history of construction delays and cost overruns.

But the 4-1 vote is a major milestone: it’s the NRC’s first license approval since 1978, the year the Unit 2 on Three Mile Island in Pennsylvania was licensed. Just a year later, in