U.S. officials expected to announce fusion energy breakthrough in clean, unlimited power

The Energy Department is expected to announce Tuesday that scientists have reached a breakthrough in nuclear fusion in their quest to produce a technology to provide clean, unlimited and affordable power.

Scientists have researched fusion since the 1950s, and the Biden administration is likely to affirm the massive, decades-long investment, according to the Washington Post reported. 

"To most of us, this was only a matter of time," a senior fusion scientist told the newspaper.

Energy Secretary Jennifer Granholm is expected to make the announcement Tuesday at a media event her department is promoting as the unveiling of a "major scientific breakthrough."

The department and the lab declined to comment to the Post, but an official said researchers are still finalizing their analysis and will not publish official findings before Tuesday.