The first new nuclear reactor built from scratch in the United States in nearly half a century successfully split its first atoms last week, signaling that one of the countrys biggest and most controversial energy projects could finally be nearing completion.

Almost 14 years after receiving its first permits, Unit 3 of the Alvin W. Vogtle Electric Generating Plant, a two-reactor facility in rural eastern Georgia, finally went critical, meaning the reactor sustained a chain fission reaction using its load of uranium fuel. The successful test run, which The Macon Telegraph in central Georgia aptly compared to igniting the pilot light of a gas stove, set in motion the final stages of a process to ready the reactor to deliver electricity to the Peach States grid in as little as six months.

If its twin, Unit 4, follows suit later this year as planned, this one midsized facility near the South Carolina border will become the nations second-largest power plant, supplying millions of homes and a growing number of factories making solar panels, batteries and electric vehicles with steady, carbon-free electricity.

When you consider the history of safe and reliable operations at Vogtle Units 1 and 2 for decades now, it puts todays milestone in perspective that Plant Vogtle will be a four-unit site making it the largest of its kind in the U.S., Chris Womack, the chief executive of plant owner Georgia Power, said in a statement. This is a truly exciting time as we prepare to bring online a new nuclear unit that will serve our state with clean and emission-free energy for the next 60 to 80 years.